Search

• A novel multi-site ferrocene-based benzimidazolium receptor 1 was synthesized. • The receptor 1 had been characterized by single-crystal X-ray diffraction analysis and DFT calculation. • The receptor 1 had been proven to be highly selective and sensitive to F −and OH−. A novel multi-site receptor 1 bearing four ferrocenyl arms comprising benzimidazolium moieties was synthesized and structurally characterized by IR, NMR, elemental analysis, mass spectra. Moreover, the structure of receptor 1 was confirmed by X-ray crystallography, it was clear that the cationic heterocyclic was interacted with PF 6 − through C–H···F hydrogen bonds. Its electrochemical properties of sensing the various anions were investigated by cyclic voltammograms (CV) and differential pulse voltammetry (DPV), the receptor 1 displayed a significant cathodic shift for F −and OH−. The addition of F − and OH−to the solution of receptor 1 resulted in obvious absorption changes in the UV–Vis spectrum, showing that receptor 1 was an excellent sensor for these analytes (F −: LOD = 3.11 × 10−6 M, LOQ = 1.03 × 10−5 M, K a = 5.83 × 105 M −1; and OH–: LOD = 1.36 × 10−6 M, LOQ = 4.11 × 10−5 M, K a = 9.03 × 105 M −1). 1H NMR titrations demonstrated that anion was recognized by receptor 1 through (C–H)+··· X − and C–H···X hydrogen bonds, the binding process involve initial formation of hydrogen bond and followed by deprotonation. [Display omitted] [ABSTRACT FROM AUTHOR]

• Aqua-complexes based on the organometallic fac -[M(CO) 3 ]+ (M = Re and 99mTc) core. • The [ Re (CO) 5 Br]-catalysed mono-esterification of pyrimidine-4,6-dicarboxylic acid. • Model complexes for future design of imaging and therapeutic radiopharmaceuticals. The current study highlights on the synthesis and characterization of aqua-complexes of the fac -[M(CO) 3 ]+ (M = Re and 99mTc) core with pyrimidine-4,6-dicarboxylic acid (H 2 pmdc) and its monoester 6-(ethoxycarbonyl)pyrimidine-4-carboxylic acid (Hetpmdc), which are the model for future design of imaging and therapeutic radiopharmaceuticals. Complexes [M(CO) 3 (OH 2)(Hpmdc)] (M = Re (1) and 99mTc (2)) were formed from the reaction of H 2 pmdc with [Re(CO) 5 Br] in water and aqueous solution of [99mTc(CO) 3 (OH 2) 3 ]+ respectively. The reaction of [ Re (CO) 5 Br] with H 2 pmdc in ethanol (EtOH) has also studied and led to the complex [Re(CO) 3 (OH 2)(etpmdc)] (3), where etpmdc−is 6-(ethoxycarbonyl)pyrimidine-4-carboxylate anion which was formed from the mono-esterification of H 2 pmdc in parallel with its coordination to the fac -[Re(CO) 3 ]+ unit. The complex [99mTc(CO) 3 (OH 2)(etpmdc)] (4) was formed in parallel with 2 by reacting H 2 pmdc with aqueous solution of [99mTc(CO) 3 (OH 2) 3 ]+ and ethanol. The chemical identification of 1 and 3 was achieved by using 1H NMR, 13C NMR, IR, ESI-MS and elemental analysis. Complex 3 was furtherly identified by using single crystal X-ray crystallography. The structural similarities of 1 and 2 was assessed by coinjection of both complexes in the HPLC with UV/Vis detection coupled with a γ-detector followed by comparison of retention times of the γ-peak of 2 and the UV-peak of 1 which allowed unambiguous identification of 2. Similarly, the formation of complex [99mTc(CO) 3 (OH 2)(etpmdc)] (4) in parallel with 2 was assessed by coinjection of complexes 1 and 3 with the product from the reaction of H 2 pmdc with aqueous solution of [99mTc(CO) 3 (OH 2) 3 ]+ and ethanol in the same HPLC as one used for the structural identification of 2 followed by comparison of retention times of the γ-peaks of 2 and 4 and the UV-peaks of 1 and 3. The reaction of pyrimidine-4,6-dicarboxylic acid (H 2 pmdc) with [ Re (CO) 5 Br] and [99mTc(CO) 3 (OH 2) 3 ]+ in water and aqueous ethanol (EtOH) led to the aqua-complexes 1 – 4 , which are the model for future design of imaging and therapeutic radiopharmaceuticals. [Display omitted] [ABSTRACT FROM AUTHOR]

• Improved access to 1,3-benzotellurazoles. • Regiospecific ortho tellurination of ureas via Te-carbonyl coordination. • Preparation of previously inaccessible 1,3-tellurazole derivatives. • Organotellurium compounds with high stability to heat, light and moisture. • X-ray crystallographic data for new organotellurium compounds. A method has been developed to prepare previously inaccessible substituted 1,3-benzotellurazoles following an efficient two-step process, consisting of the tellurination of electron rich phenyl ureas with tellurium tetrachloride and subsequent ring closure of the resulting aryl tellurium trichlorides. Tellurination occurs regiospecifically ortho to the urea moiety due to intramolecular Te–O coordination, producing highly crystalline solids that are readily isolated in yields up to 83 %. Subsequent ring closure, accomplished by heating with phosphorus trichloride and subsequent reduction with hydrazine hydrate, provides access to 1,3-benzotellurazole derivatives. Selected products were characterized by X-ray crystallography. [Display omitted] [ABSTRACT FROM AUTHOR]

• Ruthenium methoxy and ruthenium vinylidene complexes with Me 3 tacn ligands were synthesized. • The prepared new ruthenium complexes were characterized by X-ray crystallography. • The photocatalytic H 2 evolution by water splitting of the complexes was investigated. Treatment of [(Me 3 tacn)RuIII(κ2-S 2 CNR 2)Cl]PF 6 (Me 3 tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) with methanol in the presence of zinc powder in air afforded four ruthenium methoxy complexes [(Me 3 tacn)RuIII(κ 2-S 2 CNR 2)(OCH 3)]PF 6 (R = Me 1 , Et 2 , nPr 3 , iPr 4). Further reactions of complexes 1–4 and phenylacetylene gave four ruthenium vinylidene complexes [(Me 3 tacn)(κ2-S 2 CNR 2)Ru=C=CHPh]PF 6 (R = Me 5 , Et 6 , nPr 7 , iPr 8). Molecular structures of complexes 1, 2, 3, 6, 7 and 8 were established by single crystal X-ray diffraction analysis. Moreover, all complexes were characterized by infrared, UV–vis, fluorescence and mass spectrometry, and their electrochemical properties were also investigated. The visible-light-induced catalytic properties of complexes 5–8 for H 2 evolution by water splitting were explored. A series of ruthenium methoxy and ruthenium vinylidene complexes stabilized by sulfur ligands, supported by saturated tridentate amine, 1,4,7-trimethyl-1,4,7-triazacyclononane, was synthesized and structurally characterized. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis of a series of substituted triarylborane-based building blocks with extended π-conjugated systems has been achieved. • Introduction of bulky sterically demanding groups around the boron atom results in air-stable triarylboranes with wide-conjugated systems. • All the triarylboron systems exhibit a propeller structure as evidenced by X-ray crystallography. • These C 3 -symmetric boron compounds are useful building blocks for 2-D framework materials such as COFs and POPs and in fields such as optoelectronics and sensing. Synthesis of C 3 -symmetric triarylboranes, tris(4-bromo-2,6-dimethylphenyl)-borane (1) , N,N',N''-(boranetriyltris(3,5-diisopropyl-3′,5′-dimethyl-[1,1′-biphenyl]-4′,4-diyl))tris(1,1-diphenylmethanimine) (2), N,N',N''-(boranetriyltris(3′,5′-dimethyl-[1,1′-biphenyl]-4′,4-diyl))tris-(1,1-diphenylmethanimine) (3), 4′,4′'',4′''''-boranetriyltris(3′,5′-dimethyl-[1,1′-biphenyl]-4-carbaldehyde) (4), 4,4′,4′'-boranetriyltris(3,5-dimethylaniline) (5), 4′,4′'',4′''''-borane-triyltris(3′,5′-dimethyl-[1,1′-biphenyl]-4-carbonitrile) (6), 4′,4′'',4′''''-boranetriyltris(3′,5′-dimethyl-[1,1′-biphenyl]-4-amine) (7), and 4,4′,4′'-boranetriyltris(3,5-dimethylbenzaldehyde) (8) has been accomplished using well-known synthetic methodologies. These new potential building blocks have been characterized by various spectroscopic and analytical techniques and their photophysical properties have been examined. It is observed that photophysical properties of these compounds are enhanced with π conjugation expansions along the branches when donor moieties such as -NH 2 groups are present at the para-position of the aryl rings. The highest quantum yield of 0.293 is observed for 4′,4′'',4′''''-boranetriyltris(3′,5′-dimethyl-[1,1′-biphenyl]-4-amine) (7). Interestingly, red-shifted fluorescence spectra follow the same trend as absorption spectra. The fluorescence lifetime increases with the number of donor moieties. The present findings demonstrate the possible use of these C 3 -symmetric boron-containing building blocks in developing new polymeric materials with improved photophysical properties for various applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new arene Ru(II) complexes bearing TPA fused benzhydrazone ligands have been reported. • The piano-stool geometry was found from X-ray diffraction studies. • Orbitals of the ligand create frontiers LUMO although LUMO+2 is localized on [(p -cymene)RuCl] fragment. • Calculated Wiberg bond indexes close to 0.76 and 0.83 for Ru-N and Ru-O, respectively. • Short intermolecular CH...π and Ru-Cl...π contacts are presented in the complex. A ruthenium complex of the type Ru[ η 6(p –cymene)Cl(L)] where L = Triphenylamine (TPA) appended O^N bidendate benzhydrazone ligand was synthesized and characterized by various analytical and spectral [UV, FT-IR, NMR (1H and 13C) and HRMS] methods. The solid state molecular structure of the ruthenium complex was investigated with the aid of X-ray crystallography results with pseudo-octahedral geometry around the metal centre. FT-IR spectroscopy confirms the coordination via the azomethine nitrogen and imidolate oxygen. Density Functional theory (DFT) calculations have been used to analyse the composition of frontiers orbitals. The bonding interactions between the ligand and ruthenium complex fragments have been examined by EDA. The spin-allowed singlet transitions were calculated with the TD-DFT method. NBO analysis shows that the donation from ligand to metal has value of 136.64 kcal/mol and the back donation is equal to 109.61 kcal/mol. Hence the ligand is a σ-donor with weak π-acceptor properties. The DOS spectrum of both ligand and complex were plotted in terms of Mullikan population analysis were calculated using the GassSum program. Further, the relative contributions to the Hirshfeld surface area for the various close intermolecular contacts of ruthenium complex are investigated and H...H interactions plays an important role for the construction of the crystal structure of the ruthenium complex. [Display omitted] [ABSTRACT FROM AUTHOR]

• Two rare examples of dithiocarbamates derivative complexes of Os, i.e. a trithiocarbamate-dithiocarbamate complex cis -[Os(CO) 2 (S 2 CNMe 2)(S 3 CNMe 2)] (2) and a binuclear [Os 2 (CO) 3 (S 2 CNMe 2) 2 (µ-CNMe 2)(µ-SCNMe 2)] (3) that contains dithiocarbamate, thiocarboxamide and amino-carbyne ligands. • Examples of sulfur insertion into an Os-S bond of cis -[Os(CO) 2 (S 2 CNMe 2) 2 ] (1) and the oxidative addition of a C-S bond in Me 4 TMS. • Crystal structures for all new osmium complexes Thermolytic reactions of [Os 3 (CO) 12 ] with tetramethylthiuram disulfide (Me 4 TDS) and tetramethylthiuram monosulfide (Me 4 TMS) are described. While both afford the anticipated bis(dithiocarbamate) complex cis -[Os(CO) 2 (S 2 CNMe 2) 2 ] (1) as the major product, unexpected secondary products result in both cases. With Me 4 TDS this is the trithiocarbamate-dithiocarbamate complex cis -[Os(CO) 2 (S 2 CNMe 2)(S 3 CNMe 2)] (2) resulting (formally) from sulfur insertion into an Os-S bond. Heating 1 with further Me 4 TDS did afford 2 , albeit in small amounts and on a timeframe incompatible with its formation under the initial reaction conditions. From the Me 4 TMS reaction, binuclear [Os 2 (CO) 3 (S 2 CNMe 2) 2 (µ-CNMe 2)(µ-SCNMe 2)] (3) is a secondary product. It contains dithiocarbamate, thiocarboxamide and amino-carbyne ligands, the last two resulting (formally) from the oxidative addition of a C-S bond in Me 4 TMS. Both new complexes have been characterised by X-ray crystallography. [Display omitted] [ABSTRACT FROM AUTHOR]

• Single-crystal X-ray analyses were performed for complexes 2a-2e. • Products in the catalytic reaction, in the presence of 1 mol% catalyst was obtained with good yields. • The crystal structures of the complexes revealed square planar geometry around palladium. • In reactions using different heteroaryls, the corresponding products were obtained in moderate to good yields in the presence of 1 % mole catalyst loading. Herein, we reported the synthesis of six new palladium complexes (2a-2f) containing benzimidazole core and examined their catalytic activities in the direct arylation of heteroaromatic species with aryl bromides. For this purpose, a new series of palladium(II) complexes bearing N -coordinated benzimidazole complexes have been synthesized and fully characterized by elemental analysis, FT-IR, 1H NMR and 13C NMR spectroscopies. Additionally, the structures of the complexes 2a - 2e have been characterized by X-ray crystallography. Further, direct arylation reactions, using KOAc as base and DMAc as solvent under inert conditions, were carried out with the synthesized complexes in the presence of various aryl bromides, and 1-methylpyrrole-2-carboxaldehyde, furfuryl acetate, 2-acetylfuran and 2-acetylthiophene. Moreover, moderate to high yields were obtained in the direct arylation of heteroarenes and aryl bromides under 1 % mol catalyst loading conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

• Reactions of saccharinate-bridged triosmium cluster with diphosphines. • Synthesis and structure of tri- and hexaosmium clusters bearing saccharinate and diphosphine ligands. • Different coordination modes of diphosphines. • Fluxional behavior of coordinated diphosphines in solution. The reactivity of saccharinate-bridged triosmium cluster [Os 3 (CO) 10 (μ-H)(μ-sac)] (1) with two diphosphines namely bis(diphenylphosphino)methane (dppm) and 1,1′-bis(diphenylphosphino)ferrocene (dppf) have been investigated. Cluster 1 reacts with dppm in refluxing toluene to yield triosmium [Os 3 (CO) 9 (κ1-dppm)(μ-H)(μ-sac)] (2), [Os 3 (CO) 9 (κ1-dppm)(μ-H)(μ-sac)] (3) and [Os 3 (CO) 8 (µ-dppm)(μ-H)(µ-sac)] (4) along with the hexaosmium [{Os 3 (CO) 9 (μ-H)(µ-sac)} 2 (κ2-dppm)] (5). The dppm ligand acts as a monodentate ligand in 2 and 3 by coordinating to a single osmium, while it bridges an osmium-osmium edge in 4 and connects to triosmium units in 6. A similar reaction with dppf furnishes [Os 3 (CO) 9 (κ1-dppf)(μ-H)(μ-sac)] (6), [Os 3 (CO) 8 (µ-dppf)(μ-H)(μ-sac)] (7) and [{Os 3 (CO) 9 (μ-H)(µ-sac)} 2 (κ2-dppf)] (8) which are dppf analogues of 3 – 5 , respectively. Control experiments confirms that 3 is the precursor of 4 and 5 , while 6 is the precursor of 7 and 8. All the products are formed via substitution of carbonyl by the diphosphine, and have been characterized by analytical and spectroscopic data. The molecular structures of 2 and 4 – 7 have been determined by X-ray crystallography. Cluster 7 shows fluxional behavior in solution at room temperature, and its fluxionality has been probed by VT NMR experiments. [Display omitted] [ABSTRACT FROM AUTHOR]

• Four new dinuclear lanthanide complexes derived from a mono-functionalized calix[4]arene ligand have been prepared and characterized. • The solid-state structures of [La 2 (mono-O-propargyl-calix[4]arene) 2 (MeOH) 4 ] and [La 2 (mono-O-propargyl-calix[4]arene) 2 (MeOH) 4 ] have been determined by X-ray diffraction analysis. • Their ability of the lanthanum complex to react with azides in a click reaction has been demonstrated. The ability of the propargylated calix[4]arene ligand H 3 L (= 25-(2-propynyloxy)-26,27,28-trihydroxy-calix[4]arene) to bind lanthanide ions has been studied. The triply deprotonated ligand was found to support dinuclear neutral complexes of composition [Ln 2 L 2 (MeOH) 4 ] (Ln= La (1), Gd (2), Tb (3), Tm (4)). Spectroscopic data for 1 – 4 as well as X-ray crystallographic analysis of single crystals of 1 ∙(MeOH) 2 and 2 ∙(MeOH) 2 reveal that two [Ln L ] entities dimerize via two phenolato groups to generate a centrosymmetric (MeOH) 2 O 3 Ln(μ-O) 2 LnO 3 (OHMe) 2 core structure. The Ln3+ ions reside in a distorted mono-capped octahedral coordination environment. Squid magnetic measurements for the Gd3+ and Tb3+ complexes agree with the formulation as dinuclear compounds, and reveal the presence of very weak antiferromagnetic exchange interactions (J < 0.1 cm−1). The ability of the La3+ complex to react with azides in a click reaction is also demonstrated. Dinuclear lanthanide complexes of a propargylated calix[4]arene ligand H 3 L (= 25-(2-propynyloxy)-26,27,28-trihydroxy-calix[4]arene) have been synthesized and characterized. Their ability to react with azides in a click reaction has been demonstrated. [Display omitted] [ABSTRACT FROM AUTHOR]

• New sterically bulky aryl and aliphatic substituted diamide ligands have been reported. • A series of novel germylenes were prepared and their steric profile assessed using computational models. • The extremely bulky 2,4,6-tricyclohexylphenyl substituent provides greater steric protection to the germanium centre, compared to previously reported germylenes incorporating smaller aryl groups, utilising the same ligand back-bone architectures. In this contribution, three novel diamine pro-ligands, incorporating sterically bulky aryl and aliphatic N-substituents, have been developed; viz. (NCNTCHP)H 2 (NCNTCHP = {(TCHP)NCH 2 } 2 CH 2 , TCHP = 2,4,6-tricyclohexylphenyl), (NONTCHP)H 2 (NONTCHP = {(TCHP)NSiMe 2 } 2 O), and (NONAd)H 2 (NONAd = {(Ad)NSiMe 2 } 2 O; Ad = 1-adamantyl). Through salt metathesis or transamination synthetic approaches, the N-heterocyclic germylenes, [:Ge(NCNTCHP)], [:Ge(NONTCHP)], and [:Ge(NONAd)], have been prepared and crystallographically characterized. The electronic structure of each germylene was studied by DFT calculations. The steric profile of the germanium-bound ligands was also assessed using computational models, and the results compared to those for structurally similar compounds. Significant steric crowding of the germanium centre (>70 % ligand coverage) was observed for [:Ge(NCNTCHP)] and [:Ge(NONTCHP)], while [:Ge(NONAd)] exhibited substantially less steric saturation at the metal centre (∼62 % ligand coverage). Through these studies, we have shown the potential suitably of the developed ligands to stabilise other low-valent main-group species. Synopsis: A range of very bulky 6-membered heterocyclic diamido germylenes were synthesised and their structures investigated using X-ray crystallography and computational methods. [Display omitted] [ABSTRACT FROM AUTHOR]

• Eight novel organic antimony (V) complexes were synthesized and characterized. • X-ray crystallography revealed a mono- and binuclear arrangement. • Complexes 4, 8 demonstrated enhanced activity against HepG-2 and A549 cell lines. • Complex 3 exerted a potent inhibitory effect on MRSA. • Complex 4 exhibited notable inhibition against fungal strains in PP plants. Eight new organoantimony complexes, R 3 Sb L 2 (R = Ph, p -MePh; L = L1, L2) and (R 3 Sb) 2 O L 2 (R = pHPh, m -MePh; L = L1, L2), [Ph 3 Sb(C 5 H 3 N 2 O 2) 2 ] (1), [(Ph 3 Sb) 2 O(C 5 H 3 N 2 O 2) 2 ] (2), [(p -tol) 3 Sb(C 5 H 3 N 2 O 2) 2 ] (3), [(m -tol) 6 Sb 2 O(C 5 H 3 N 2 O 2) 2 ] (4), [Ph 3 Sb(C 5 H 3 N 2 O 2) 2 ] (5), [(Ph 3 Sb) 2 O(C 5 H 3 N 2 O 2) 2 ] (6), [(p -tol) 3 Sb(C 5 H 3 N 2 O 2) 2 ] (7) and [(m -tol) 6 Sb 2 O(C 5 H 3 N 2 O 2) 2 ] (8), were designed and synthesized by the reaction of 4-pyrimidine carboxylic acid (HL1) or 5-pyrimidine carboxylic acid (HL2) with organoantimony precursors. All the complexes were characterized by elemental analysis, FT-IR, NMR (1H and 13C), and single crystal X-ray diffraction analysis. Crystal structure results reveal that the central antimony atom of all the complexes displays a triangular biconical geometry. Among them, complexes 1, 3, 5 and 7 show a monomeric structure, while complexes 2, 4, 6 and 8 have a dimeric structure with oxygen bridges. The in vitro cytostatic activities of the eight complexes against a human alveolar basal epithelial lung cancer cell lines (A549) and hepatocellular carcinoma cell lines (HepG-2) were investigated, and the results showed that the organoantimony derivatives with the tolyl groups (3, 4, 7, 8) exhibited higher in vitro cytostatic activities compared with those with the phenyl groups (1, 2, 5, 6). At the same time, bacteriostatic tests were conducted to assess the inhibitory effects of complexes 1–8 against three prevalent plant pathogenic fungi and one bacterium. The results revealed that complex 4 exhibited significant fungicidal activities, on the other hand, complex 3 exhibited higher antibacterial activity against MRSA. These results will provide significant guidance for the further exploration of potential efficient biological activity complexes. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis and characterization of two novel pyrene based rhenium (I) complexes. • Comparison of experimental findings with theoretical calculations involving DFT. • The binding of the complexes to DNA were examined by spectroscopic measurements. • The binding parameters have been calculated using equations from literature. Biologically active pyrene based rhenium (I) complexes (1 – 2) were designed as fac -[Re(CO) 3 LCl], (where L = L 1 (E)-N-(quinolin-8-ylmethylene)pyren-4-amine and L 2 (E)-N-(pyridin-2-ylmethylene)pyren-4-amine) and structurally characterized by X-ray crystallography, which suggested a distorted octahedral geometry around the metal centre. The complexes were also characterised by various spectroscopic techniques. The binding of the rhenium complexes to CT-DNA was examined by UV–Vis spectroscopy, fluorescence quenching studies with ethidium bromide and viscosity measurements. Between both the complexes, 2 showed a greater binding ability to CT-DNA, as is evident from the numerical value of the binding constant, calculated using the Benesi-Hildebrand equation. [Display omitted] [ABSTRACT FROM AUTHOR]

• Three 2,7-alkynyl(aryl)-3,6-dimethoxy-9,9-diphenylsilafluorenes have been synthesized. • The substituents are -(trifluoromethyl)phenyl, -(malononitrile)phenyl, and -nitrobenzene. • These new compounds are fluorescent and stable with desirable emission properties. 2,7-Disubstitution and DFT-guided design have been used to tune emission wavelengths for three new fluorescent 2,7-alkynyl(aryl)-3,6-dimethoxy-9,9-diphenyl-sila- and germafluorenes. Two germafluorenes with trifluoromethyl phenyl and nitrobenzene substituents were prepared using a Pd-catalyzed Sonogashira coupling reaction to incorporate alkynyl(aryl) groups at the 2,7-positions of the ring. Another new silafluorene was prepared by modifying a benzaldehyde-substituted silafluorene to incorporate a malononitrile group. These compounds were characterized utilizing multinuclear NMR, UV–Vis, and fluorescence spectroscopic techniques. The germafluorene with the trifluoromethyl phenyl substituent was also characterized via elemental analysis and X-ray crystallography. These metallafluorenes (MFs), which are yellow or red-orange crystals in the solid state, showed a wide range of quantum yields and spectroscopic features, with the malononitrile-containing MF exhibiting significantly red-shifted emission relative to other MFs. These data demonstrate the value in applying DFT to MF design and the dramatic impact the 2,7-substituent has on the optical properties of this class of compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

• Organometallic iridium complexes, (C^N) 2 Ir(BOX), are reported with chiral bis-oxazoline (BOX) ancillary ligands. • (C^N) 2 Ir(BOX) complexes display highly efficient phosphorescence across the visible spectrum. • Δ and Λ diastereomers with cyclometallated phenyl-pyridine ligands, (ppy) 2 Ir(BOX), complex were isolated and characterized. • Diastereomers have identical properties, except for circular dichroism (CD) and circularly polarized emission (CPL) spectra. • An unprecedented match/mismatch effect between ligand chirality and the CPL magnitude is observed in these diastereomers. Organometallic iridium complexes with two cyclometalated ligands (C^N) and one bis-oxazoline derived ancillary ligand (L^X), i.e. (C^N) 2 Ir(L^X), are reported. The C^N ligands are 1-phenylpyrazoline (ppz), 2-(4,6-difluorophenyl)pyridine (F 2 ppy), 2-phenylpyridine (ppy), 1-phenylisoquinoline (piq). The box ligand is (4S-+)-phenyl-α-[(4S)- phenyloxazolidin -2- ylidene ]-2-oxazoline-2-acetonitrile. The emission of these complexes span across the visible and into the near-ultraviolet region of the electromagnetic spectrum with moderate to high photoluminescence quantum yields (Φ PL = 0.45–1.0). These complexes were found to emit from a metal-ligand to ligand charge transfer (ML'LCT) state and have lifetimes (1.3–2.1 μs), radiative rates (105 s−1), and nonradiative rates (104–105 s−1) comparable to state-of-the-art iridium emitters. The (ppy) 2 Ir(BOX-CN) complexes were resolved into the Δ- and Λ- diastereomers using differences in their solubility and additionally characterized by x-ray crystallography, stability, and chiroptic studies. The high Φ PL of these isomers results in the best to date brightness for circularly polarized luminescence (CPL) from iridium complexes (7.0 M−1 cm−1), with dissymmetry factors of −0.57 × 10−3 and +1.9 × 10−3 for 3Δ and 3Λ , respectively. The significant difference in CPL magnitude between 3Δ and 3Λ likely arises from interligand interactions (edge-to-face arrangement versus strong π-π interaction) for the pendant phenyl ring of the BOX-CN ligand which differ for the two isomers. [ABSTRACT FROM AUTHOR]

Dimethylpalladium complex bearing PS 3 -type tripodal tetradentate ligand, [PdMe 2 {P(C 6 H 4 -2-S- i -Pr) 3 }], was synthesized by the reaction of [PdCl{P(C 6 H 4 -2-S- i -Pr) 3 }]X (X = Cl, BF 4) with methyllithium (Br free). The dimethylpalladium complex reacted with an equimolar amounts of HCl to give the corresponding chloromethylpalladium complex, [PdClMe{P(C 6 H 4 -2-S- i -Pr) 3 }], while the similar reaction using 2 M amounts of HCl afforded the dichloropalladium complex, [PdCl{P(C 6 H 4 -2-S- i -Pr) 3 }]Cl. The detailed structures of the complexes were revealed by X-ray crystallography and variable temperature 1H NMR studies. Image 1 • [PdMe 2 (L)] (L: PS 3 -type tripodal tetradentate ligand) was synthesized. • Reaction of [PdMe 2 (L)] with HCl afforded [PdClMe(L)] or [PdCl 2 (L)] selectively. • The detailed structure of [PdMe 2 (L)] and [PdClMe(L)] was studied by X-ray analysis. • The dynamic behavior of [PdMe 2 (L)] and [PdClMe(L)] was studied by VT NMR. [ABSTRACT FROM AUTHOR]

Phosphine-arenesulfonate ligands that contain 1-3 methoxy substituents on the benzo linker, P(2-OMe-Ph) 2 (2-SO 3 Na-5-OMe-Ph) (Na[ 1a ]), P(2-MeO-Ph) 2 (2-SO 3 Na-4,5-(OMe) 2 -Ph) (Na[1b]) and P(2-MeO-Ph) 2 (2-SO 3 Li-3,4,5-(OMe) 3 -Ph) (Li[ 1c ]) were synthesized and isolated in 52–85% yield. Reaction of Na[ 1a,b ] and Li[ 1c ] with (COD)PdMeCl and pyridine generates the corresponding (PO)PdMe(pyridine) complexes 2a-c. 2a and 2b were isolated in crystalline form in 59% and 86% yield, respectively, while 2c decomposed during attempted isolation. 2a,b polymerize ethylene to linear polyethylene and copolymerize ethylene with vinyl fluoride (VF) to linear copolymer with ca. 0.5 mol % VF incorporation. The phosphine-arenesulfonate ligands Na[1a , b] and Li[1c] react with (COD)PdMeCl and pyridine to generate (PO)PdMe(pyridine) complexes 2a-c , which contain 1-3 methoxy groups on the benzo linker. 2a , b have been characterized by X-ray crystallography while 2c is thermally unstable. The ethylene polymerization and ethylene/vinyl-fluoride copolymerization behavior of 2a , b have been investigated. Image 1 • Phosphine-arenesulfonate ligands with OMe-substituted benzo linkers were prepared. • The corresponding (PO)PdMe(py) complexes were prepared and characterized. • These (PO)PdMe(py) complexes polymerize ethylene to linear polyethylene. • These (PO)PdMe(py) complexes copolymerize ethylene and vinyl fluoride. [ABSTRACT FROM AUTHOR]

Benzoylhydrazine based Schiff base-ligated two new copper(II) complexes, [Cu(L1) 2 ] (1) and [Cu(L2) 2 ] (2) were synthesized by the reaction of Cu(CH 3 COO) 2 ·H 2 O with respective Schiff base ligand 1-[(4-nitrophenyl)ethylidene] benzohydrazide (HL1) or 1-[(4-methoxyphenyl)ethylidene] benzohydrazide (HL2). Both complexes were isolated as greenish solid and fully characterized by elemental analysis, FT-IR, EPR, thermo-gravimetric (TG) analysis and Cyclic Voltammetry. The molecular structures of both complexes have also been determined by single crystal X-ray crystallography, which confirmed the coordination of Schiff base ligands through N, O donor atoms and distorted square planar geometry around the Cu(II) ion. Both complexes were found to be good homogeneous catalysts for the synthesis of a wide range of substituted thioethers and 5-substituted 1 H -tetrazoles in 92% and 93% yield, respectively, at a low catalyst loading (0.5 mol%). The bond angles and distances, as discerned from the DFT calculations, commusurated with the experimental findings. The energy difference between the HOMO and the LUMO, calculated from DFT studies, was found to be 5.645 eV and 6.459 eV for complex 1 and complex 2 , respectively. These results are in harmony with the observed higher catalytic activity of complex 1. Image 1 • Synthesis of benzoylhydrazine based Schiff base-ligated two new copper(II) complexes. • Fully characterized by elemental analysis, FT-IR, EPR, TGA and Cyclic Voltammetry. • Structures of the complexes were confirmed by single crystal X-ray crystallography. • Efficient catalysts for synthesis of thioethers and 5-substituted 1 H -tetrazoles. • DFT calculations are consistent with the experimental bond lengths/bond angles and catalytic activities. [ABSTRACT FROM AUTHOR]

The reaction of (NHC)ZnEt 2 (1) with 2,6-dimethylphenol in the molar ratio 1:2 at room temperature resulted in a monomeric zinc dimethylphenoxide [(NHC)Zn(OC 6 H 3 -2,6-Me 2) 2 ] (NHC = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) (2). Whereas, the reaction of 1 with 2,6-dimethylphenol in the presence of water in the molar ratios 1:2:0.5 or 1:2:1 afforded [(NHC) 2 Zn 2 (μ -OH)(μ -OC 6 H 3 -2,6-Me 2)(OC 6 H 3 -2,6-Me 2) 2 ] (3) and [(NHC)Zn(μ -OH)(OC 6 H 3 -2,6-Me 2)] 2 (4) respectively. Moreover, reaction of 1 with 2,6-diisopropylphenol in the presence of a base led to the isolation of [(NHC)Zn(μ -OH)(OC 6 H 3 -2,6- i Pr 2)] 2 (5). Compounds 2 – 5 have been fully characterized by spectroscopic and single crystal X-ray diffraction studies. In this paper, we have discussed the synthesis, structural characterizations of 2 – 5 and the mechanism for the formation of compounds 3 – 5 from 2. In this paper we report the synthesis and structural characterization of NHC stabilized zinc hydroxyaryloxides [NHC) 2 Zn 2 (μ -OH)(μ -OC 6 H 3 -2,6-Me 2)(OC 6 H 3 -2,6-Me 2) 2 ] (3), [(NHC)Zn(μ -OH)(OC 6 H 3 -2,6-Me 2)] 2 (4) and [(NHC)Zn(μ -OH)(OC 6 H 3 -2,6- i Pr 2)] 2 (5) by controlled hydrolysis. Image 1 • Role of sterics in the prevention of oligomers and the synthesis of zinc aryloxide and hydroxyalkoxide is demonstrated. • Controlled hydrolysis of Zinc aryloxide by stoichiometric variation of H 2 O is achieved. • Both the bridged zinc dihydroxide and bridged zinc hydroxyaryloxide is isolated. • The addition of base assists the hydrolysis of metal aryloxides [ABSTRACT FROM AUTHOR]

The efficiency of various gold compounds containing bis(phosphino)ferrocene ligands for catalyzing ring-closing reactions was examined. Six commercially available bis(phosphino)ferrocene ligands: 1,1′-bis(di tert -butylphosphino)ferrocene (dtbpf), 1,1′-bis(diphenylphosphino)ferrocene (dppf), 1,1′-bis(dicylohexylphosphino)ferrocene (dcpf), 1,1′-bis(di iso -propylphosphino)ferrocene (dippf), 1-diphenylphosphino-1′-di- tert -butylphosphinoferrocene (dppdtbpf) and 1,1′-bis(5-methyl-2-furanylphosphino)ferrocene (dfurpf) were employed in this study. In addition to the previously reported [Au 2 Cl 2 (μ-PP)] (PP = dtbpf, dppf, dcpf, dippf or dppdtbpf) compounds, [Au 2 Cl 2 (μ-dfurpf)] was synthesized and characterized by NMR spectroscopy, cyclic voltammetry and X-ray crystallography. All of these gold compounds react with Na[BArF 24 ] (BArF 24 = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) to remove a chloride and yield the cationic monochlorides, [Au 2 (μ-Cl)(μ-PP)]+. The effectiveness of the [Au 2 Cl 2 (μ-PP)] and [Au 2 (μ-Cl)(μ-PP)][BArF 24 ], either pre-formed or generated in situ , compounds for the catalytic intramolecular alkyne hydroalkoxylation of (Z)-3-methylpent-2-en-4-yn-1-ol was examined in CDCl 3 and toluene-d 8. The ring-closing of N -(prop-2-yn-1-yl)benzamide was also examined and was efficiently carried out in toluene-d 8 using [Au 2 (μ-Cl)(μ-PP)][BArF 24 ] (PP = dtbpf, dppf, dcpf, dippf, dppdtbpf or dfurpf). In addition, [Au 2 Cl 2 (μ-dppe)] and [Au 2 (μ-Cl)(μ-dppe)][BArF 24 ] were examined as catalysts for these ring-closing reactions in order to determine if the ferrocene backbone of the bis(phosphino)ferrocene ligands was important for catalysis. For several ring-closing reactions, catalytically inactive [Au 2 Cl 2 (bis(phosphino)ferrocene)] compounds were activated by the addition of Na[BArF 24 ] (BArF 24 = [B(3,5-C 6 H 3 (CF 3) 2) 4 ]-) to give [Au 2 (μ-Cl)(bis(phosphino)ferrocene)][BArF 24 ]. The activated compound were generally good catalysts, and the substituents on the phosphorus atoms influence the effectiveness of the catalysts. Image 1 • Activation of [Au 2 Cl 2 (PP)] (PP = bis(phosphino)ferrocene) by Na[B(3,5-C 6 H 3 (CF 3) 2) 4 ]-. • [Au 2 (μ-Cl)(PP)][B(3,5-C 6 H 3 (CF 3) 2) 4 ] catalysis of several ring-closing reactions. • [Au 2 Cl 2 (dfurpf)] (dfurpf = 1,1′-bis(5-methyl-2-furanylphosphino)ferrocene) structure. • Electrochemistry of [Au 2 Cl 2 (PP)] compounds. [ABSTRACT FROM AUTHOR]

Abstract An acyclic flexible bis(α-iminopyridine) ligand has been employed for the stabilization of chlorostannyliumylidene and a tin(II) dication. The syntheses involve the abstraction of chloride from the tin dichloride precursor using trimethylsilyl trifluoromethane sulfonate. The apically disposed tin(II) dication exhibits electrophilic behaviour and undergoes transmetallation reaction with GeCl 2.dioxane resulting in stabilizing the Ge(II) dication. All the compounds have been characterized by NMR techniques and single crystal X-ray crystallography. Graphical abstract A pyramidal tin(II) dication has been stabilized within an acyclic bis(α-iminopyridine) ligand framework. The apical disposition of the tin(II) dicationic center allows its further reactivity. While the dication is inherently electrophilic, the presence of significant s -character restricts nuclephilicity. The tin(II) diaction undergoes transmetallation with GeCl2.dioxane stabilizing Ge(II) dication. Image 1 Highlights • A Sn(II) dication has been stabilized by bis(α-iminopyridine). • The Sn(II) dicationic site is apically disposed allowing further reactivity. • High s -character of the lone pair on Sn(II) dication prohibits its nucleophilicity. • The Sn(II) dication shows electrophilic behaviour. • The Sn(II) dication undergoes transmetallation reaction with GeCl2.dioxane. [ABSTRACT FROM AUTHOR]

Abstract New water soluble and optically active cyclopentadienyl titanium derivatives [(η5-C 5 H 5) 2 Ti{(1 R, 4 S)-ĸON,(R)NH}Cl] (R = Bn (Benzyl) 1a ', 2-pic (2-picolylamine) 1b ') have been synthesized. The novel compounds along with those previously described [(η5-C 5 H 5) 2 Ti{(1 S, 4 R)-ĸON,(R)NH}Cl] (R = Bn 1a , 2-pic 1b) were evaluated by polarimetry, ultra-violet and circular dichroism spectroscopy. The structure of 1b was determined by single crystal X-ray crystallography and showed a unique terminal monohapto Ti O disposition of the oximato ligand. All enantiomers have been tested against several cancer cell lines in vitro : prostate PC-3 and DU-145, lung A-549, pancreas MiaPaca-2, colorectal HCT-116, leukemia Jurkat and cervical HeLa. In addition, 1a , 1b and 1b ' were tested against non-tumorigenic prostate RWPE-1 cell line. After 24 h of incubation, 1b and 1b ' were moderately active against Jurkat and A-549 cells. The anti-proliferative effect of titanium compounds on prostate PC-3, DU-145 and RWPE-1 cell lines was also assessed after 72 h of drug exposure. The cytotoxic profile of the enantiomers was similar, exception made for the PC-3 cells, with S,R- isomers exhibiting cytotoxicities 2 to 3 times higher than R,S -compounds. Under these conditions, derivative 1b showed calculated IC 50 values better than those of Tacke's Titanocene-Y (bis-[(p -methoxybenzyl)cyclopentadienyl]titanium(IV) dichloride) on both the prostate PC-3 and DU-145 cells. 1a and 1b cytotoxic behaviour shows certain selectiveness, with activities 2–4 times lower on normal prostate RWPE-1 than on cancer PC-3 cells. Furthermore, 1b produces higher cytotoxicity on prostate PC-3, DU-145 and RWPE-1 cells than the additive dose of titanocene dichloride and pro-ligand b·HCl. Additionally, compound-DNA interactions have been investigated by equilibrium dialysis, Fluorescence Resonance Energy Transfer (FRET) melting assays and viscometric titrations, which suggest that these metal complexes and/or their hydrolysis products bind DNA either in the minor groove or externally. Graphical abstract Image 1 Highlights • Synthesis of novel enantiopure titanocene amino-oximato compounds is reported. • The X-ray crystal structure of one of the compounds shows a unique monohapto Ti-ON coordination. • One enantiomer shows IC 50 values lower than Titanocene-Y on both PC-3 and DU-145 cells. • One enantiomer is more active than additive doses of Ti(η5-C 5 H 5)Cl 2 and oxime pro-ligand. [ABSTRACT FROM AUTHOR]

Abstract The Sonogashira reaction of 9-bromoanthracene and ethynyltrimethylsilane furnishes not only the anticipated 9-(trimethylsilylethynyl)anthracene and 2-(trimethylsilyl)aceanthrylene but also (E)-4-(9-anthracenyl)-1,3-bis(trimethylsilyl)-but-3-en-1-yne, all in moderate yields. A mechanistic rationale is proposed that invokes the intermediacy of bromo(anthracenyl)bis(triphenylphosphine)palladium(II) that can undergo coupling either directly, or after coordination and migratory insertion of the free alkyne. Graphical abstract Coupling of bromoanthracene and substituted acetylenes using copper-free palladium catalysis conditions leads to unexpected diverse products: phenylacetylene yields a Sonogashira-type product (left), but the more electron-rich trimethylsilylacetylene gives, in two steps, an insertion product (right). Image 1 Highlights • Sonogashira coupling of 9-bromoanthracene and TMS-acetylene yields three products. • They were identified as an alkyne, an aceanthrylene and an enyne. • Yields are very sensitive to reaction conditions and the identity of the catalyst. • The products are formed competitively, not consecutively. • A mechanistic rationale is offered to account for all the products. [ABSTRACT FROM AUTHOR]

Abstract The reaction of [(η6-C 6 H 6)RuCl(μ -Cl)] 2 with chalcogenoether substituted 1 H -pyrazole ligands (L1 - L3) in methanol have yielded three novel Ru(II) half-sandwich complexes [(η6-C 6 H 6)RuCl(L)]PF 6 (1 – 3) in high yield under the ambient reaction conditions. The NMR, MS and FT-IR analytical techniques were used to identify their structures. The molecular structures of the complexes 2 and 3 were established with X-ray crystallographic analysis and revealed a pseudo-octahedral half sandwich piano-stool geometry around ruthenium in each complex. Complexes 1–3 are thermally robust and were found to be insensitive towards the air and moisture. All the complexes were found to be catalytically active and produced the excellent yields of amides (up to 95%) from corresponding aldehydes. In contrast to the previous reported catalytic systems for aldehyde to amide transformation, the present complexes 1 – 3 are very efficient and have several advantages in terms of low catalyst loading, reaction time, temperature and wide applicability for various substituted aldehydes. Owing to the stronger σ-donor coordination properties of selenium containing ligands, the complex 2 was found to be more efficient as compare to the sulphur and tellurium analogues. Graphical abstract Image 1 Highlights • Synthesis and characterization of three novel Ru(II) half-sandwich complexes of pyrazolated chalcogenoether ligands. • Catalytic potential of the complexes for one-pot conversion of aldehyde to amide. • Due to the stronger σ-donor properties of selenium, the Ru complex of Se ligand was found to be more efficient as compare to the sulphur and tellurium analogues. [ABSTRACT FROM AUTHOR]

Abstract The ylide-phosphonium salt [PPh 3 CH 2 C(O)CH 2 Cl]+Cl− was reacted with Pd(OAc) 2 to give the chloro-bridged dinuclear complex [Pd{C(H)PPh 3 C(O)CH 2 Cl}(μ-Cl)(OAc)] 2 , which experienced bridge cleavage reactions with triphenylphosphine (PPh 3) and pyridine (Py), and to prepare the new orthometallated complexes [Pd{(C,C) C 6 H 4 PPh 2 C(H)C(O)CH 2 Cl}L]Cl, [L = PPh 3 (1) and Py (2)]. The complexes were identified and characterized using various techniques. X-ray crystallography was used to determine the crystal structure of 1, which revealed the presence of an orthometallated C 6 H 4 -PPh 2 unit. CT-DNA binding interaction of the synthesis compounds was tested by fluorescence spectroscopy, UV–Vis absorption spectroscopy, and the viscometric titration method. The analysis of the obtained data indicated that the Pd complexes could bind to DNA via groove binding by the partial intercalation mode. The emission titration of bovine serum albumin (BSA) with two Pd complexes showed a static process for the fluorescence quenching mechanism of BSA. In addition, the results of competitive binding by Eosin-Y, Ibuprofen and Digoxin site markers revealed that the complexes were bound to the site I of BSA. The donor (BSA) - acceptor (Pd complexes) distance was calculated using fluorescence resonance energy transfer (FRET). Notably, molecular docking studies were used for the determination of DNA and BSA-Pd (II) complexes binding. Finally, the two complexes exhibited significant in vitro cytotoxicity against human leukemic T cell (Jurkat) and chronic myelogenous leukemia (K562) cancer cell lines using MTT([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] colorimetric. In cell cycle analysis conducted on Jurkat and K562 cells treated with ligand and Pd complexes, a decrease in DNA cell content and shift in the main population of cells toward the subG1 phase were observed. Graphical abstract Image 1 Highlights • The reactivity and coordination chemistry of phosphorous ylides are important. • The complex was characterized by single crystal X-ray diffraction study. • The complexes interact with CT-DNA via groove binding with partial intercalation. • The complexes exhibit significant in vitro cytotoxicity against cancer cell lines. [ABSTRACT FROM AUTHOR]

Abstract A new heterobimetallic [CuZn(bz) 3 (bpy) 2 ]PF 6 has been synthesized from commercially available starting materials. Its structure has been established by molar conductance, magnetic moment, IR, electronic, ESR and X-ray crystallography. Its catalysis has been established in hydrogen peroxide mediated oxidation of alcohols to aldehydes and ketones and direct formation of oximes. Graphical abstract Image 1 Highlights • A heterobimetallic [CuZn(bz) 3 (bpy) 2 ]PF 6 complex was synthesized. • Its catalytic oxidation reaction of alcohols to aldehydes and ketones has been established. • The complex was also used as catalyst for the direct formation of oxime from alcohols. [ABSTRACT FROM AUTHOR]

Abstract New dioxido-vanadium(V) complexes derived from hydrazone ligands have been synthesized in good yield. The complexes were characterized by elemental analysis, IR, UV–Visible and 1H NMR spectroscopies. The structure of both the complexes was established by Single Crystal X-ray crystallography. Complex 1 crystallized in monoclinic P2 1 /n space group, with cell parameters a = 8.3725(5) Å, b = 15.0475(17) Å, c = 32.227(3) Å, α = 90°, β = 91.846(5)o, γ = 90°. Complex 2 crystallized in triclinic P-1 space group, a = 8.1871(7) Å, b = 11.2605(17) Å, c = 11.4031(18) Å, α = 105.961(14)°, β = 110.528(12)o and γ = 96.387(10)o. Both the complexes act as efficient catalyst which can catalyse the C H bond functionalization reaction. Graphical abstract Image 1 Highlights • Dioxovanadium(V) complexes containing simple hydrazone ligands has been synthesized in good yield. • The complexes were characterized by IR, UV–Visible and 1H NMR spectroscopies. • The structure of complexes has been established by Single Crystal X-ray crystallography. • The complexes act as catalyst which efficiently catalyzed C H bond activation reaction. [ABSTRACT FROM AUTHOR]

• A strongly luminescent Re (I) complex with anionic cyanopentafluorophosphate [NCPF 5 ]–. • Characterizations of isocyanopentafluorophosphate [CNPF 5 ]– and cyanopentafluorophosphate [NCPF 5 ]– through vibrational spectroscopy. • Detailed investigation revealed the exceptionally strong π-accepting ability of anionic [NCPF 5 ]–. A tricarbonyl Re (I) phenanthroline complex (1) with anionic cyanopentafluorophosphate [NCPF 5 ]– ligand has been synthesized and characterized. Although the structure of the complex has also been determined by X-ray crystallography, the identity of the [NCPF 5 ]– needs to be confirmed by the vibrational spectroscopic study. The cyanopentafluorophosphate Re (I) phenanthroline complex 1 also exhibits phosphorescence derived from a 3MLCT excited state. Importantly, as the MLCT absorption and emission energies of 1 are comparable to those of the structurally related complexes with the strongest π-accepting anionic isocyanoborate ligands, it reveals the exceptionally strong π-accepting ability of [NCPF 5 ]–. This result suggests that [NCPF 5 ]– is a promising alternative to isocyanoborate ligands for designing phosphorescent materials, catalysts and photocatalysts. [ABSTRACT FROM AUTHOR]

• The impact of solvent on the products of the Schlenk dimerisation of 1,1-diphenylethene is explored. • The first potassium complex of the 1,1,4,4-tetraphenylbutane-1,2-diide dicarbanion is reported. • The use of 12-crown-4 enables crystallisation of the "free" 1,1,4,4-tetraphenylbutane-1,2-diide dicarbanion. The reaction between 1,1-diphenylethene and two equivalents of lithium in THF gave the complex [(Ph 2 CCH 2 CH 2 CPh 2)Li 2 (THF) 4 ] (3), which crystallised from Et 2 O/THF as the dialkyllithate salt [Li(THF) 4 ][(Ph 2 CCH 2 CH 2 CPh 2)Li(THF)] (3a). A similar reaction between 1,1-diphenylethene and sodium metal in THF gave [(Ph 2 CCH 2 CH 2 CPh 2)Na 2 (THF) 1.5 ] (4), which crystallised from THF as the polymer [(Ph 2 CCH 2 CH 2 CPh 2)Na 2 (THF) 3 ] ∞ (4a). In contrast, reactions between 1,1-diphenylethene and potassium under the same conditions gave intractable mixtures of products. However, treatment of 3 with two equivalents of KO t Bu in THF yielded the complex [(Ph 2 CCH 2 CH 2 CPh 2)K 2 (THF) 0.5 ] (5) as a deep red powder; treatment of 5 with two equivalents of 12-crown-4, followed by crystallisation from methylcyclohexane/THF, gave the adduct [(Ph 2 CCH 2 CH 2 CPh 2)K 2 (THF) 2 (12-crown-4) 2 ] (5a). A similar reaction between 3 and 12-crown-4 gave the separated ion pair [Li(THF)(12-crown-4)][Li(THF) 0.5 (OEt 2) 0.5 (12-crown-4)](Ph 2 CCH 2 CH 2 CPh 2) (3b), which contains the free 1,1,4,4-tetraphenyl-1,4-butanediide dicarbanion. X-ray crystallography revealed that the C 3 C centres of the ligands adopt a near planar geometry, irrespective of whether a metal cation is in close contact. [Display omitted] [ABSTRACT FROM AUTHOR]

• Three new ferriostannylenes having different tin substituents, ArSnFeCp(CO) 2 (1), ArSnFeCp*(CO) 2 (2), and ArSnFeCp(CO)(PMe 3) (3) were isolated. • Increasing the aryl substituent size causes closure of the interligand angle the tin atom. • Replacement of a CO group with a phosphine causes the interligand angle at the tin atom to widen. A series of ferriostannylenes of formula ArMe6SnFeCp(CO) 2 (ArMe6 = −C 6 H 3 -(C 6 H 2 –2,4,6-Me 3) 2 , Cp = η 5-C 5 H 5) (1), ArMe6SnFeCp*(CO) 2 (Cp* = η 5-C 5 Me 5) (2), and ArMe6SnFeCp(CO)(PMe 3) (3) with differing iron and/or tin substituents was synthesized. Their structures and spectroscopic properties were examined by X-ray crystallography, NMR, IR, and UV–vis spectroscopy and compared with data for related species. The structural data showed that, as the size of the terphenyl substituent increases, the C-Sn-Fe angle decreases slightly which is contrary to steric expectations. The 1H and 119Sn NMR chemical shifts of the least crowded species 1 is similar to, but slightly upfield of those of its more hindered ferriostannylene analogs. Unexpectedly, 3 displayed a 119Sn NMR chemical shift that is ca. 800 ppm downfield of 1 as a result of the substitution of one of the iron carbonyl groups with a PMe 3 ligand. This unusual finding is probably a reflection of a decreased paramagnetic shielding of the 119Sn nucleus by the more electron releasing character of the PMe 3 ligand which decreases the n→p energy gap. The infrared spectrum of 1 also displayed slightly higher ν CO frequencies, and its electronic spectrum indicated a small hypsochromic shift in the energy of its n→p transition whereas both 2 and 3 displayed much greater hypsochromic shifts than 1 consistent with the more electron donating character of the iron phosphine substituent. The results were interpreted in terms of the electronic/steric properties of the various substituents and their effects on metal electron density. [Display omitted] [ABSTRACT FROM AUTHOR]

• Ligand substitution kinetics for the reaction of Os 5 C(CO) 15 with (Z)-Ph 2 PCH=CHPPh 2. • Nido to arachno polyhedral expansion in Os 5 C(CO) 15 upon ligand addition. • DFT analysis on the stepwise conversion of arachno Os 5 C(CO) 15 [κ1-P eq -dppen] to nido Os 5 C(CO) 13 [κ2-P a ,P b -dppen] + 2CO. The reaction of the pentaosmium cluster Os 5 C(CO) 15 (1) with the diphosphine (Z)-Ph 2 PCH CHPPh 2 (dppen) has been studied over the temperature range 328–358 K. Diphosphine addition to Os 5 C(CO) 15 yields the arachno cluster Os 5 C(CO) 15 (κ1-P eq -dppen) (2) as the initially observed product. Cluster 2 transforms to the arachno cluster Os 5 C(CO) 14 (κ2-P eq ,P eq -dppen) (3) upon CO loss and chelation of the pendent phosphine moiety. The loss of a second CO in cluster 3 is accompanied by polyhedral contraction to give the square pyramidal nido cluster Os 5 C(CO) 13 (κ2-P a ,P b -dppen) (4). Clusters 2 – 4 were characterized in solution by IR and NMR spectroscopies, and the molecular structure of each new cluster was established by X-ray crystallography. The kinetics for the formation of 2 from 1 and dppen support a bimolecular process involving dppen addition to 1 analogous to the reported ligand additions to the family of M 5 C(CO) 15 clusters (where M = Fe, Ru). Cluster 2 is labile and serves as the precursor to 3 + CO, which undergoes conversion to 4 + CO. The kinetics for these reactions have been explored, and these data, in conjunction with DFT calculations, have provided mechanistic insight into the stepwise conversion of 1 and dppen to 4 + 2CO. [Display omitted] [ABSTRACT FROM AUTHOR]

• The crystal structures of several Pt(P(OR) 3) 2 X 2 were obtained and compared with spectral data. • Michaelis-Arbuzov-type dealkylation during synthesis was observed for some of the phosphite ligands. • Computational studies were used to understand the electronic structure of phosphite ligands. Air-stable phosphite-ligated platinum complexes of the form cis -Pt(P(OR) 3) 2 Cl 2 and cis -Pt(P(OR) 3) 2 Me 2 based on five small alkyl phosphite ligands have been synthesized and characterized. The crystal structures for several of these species are reported, allowing for comparison between spectroscopic and structural parameters. Michaelis-Arbuzov-type dealkylation during synthesis was observed for some of the phosphite ligands, and a dealkylated product was structurally characterized. Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) was also used to examine the electronic structure of the phosphite compounds. The QTAIM results support the increased π-acidity of the phosphite ligands compared to analogous phosphines. Thermolysis experiments were performed to examine the stability and reactivity of Pt(P(OR) 3) 2 X 2 species. It was found that coordinated P(OiPr) 3 ligands decompose via cyclometallation and propylene extrusion. Air- stable phosphite-ligated platinum complexes of the form cis -Pt(P(OR) 3) 2 Cl 2 and cis -Pt(P(OR) 3) 2 Me 2 based on five small alkyl phosphite ligands have been synthesized and characterized. The crystal structures for several of these species are reported, allowing for comparison between spectroscopic and structural parameters. Michaelis-Arbuzov-type dealkylation during synthesis was observed for some of the phosphite ligands, and a dealkylated product was structurally characterized. Density Functional Theory (DFT) and Quantum Therory of Atoms in Molecules (QTAIM) was also used to examine the electronic structure of the phosphite compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

• Crystals of single enantiomers of CpMo(NO)(η3-Methallyl)NCO contain both bent and linear NCO complexes whereas the racemic complex shows only one structure in the solid with an intermediate angle of 165.7(4)°. • Azide attack on [CpMo(NO)(CO)(η3-Methallyl)]+ proceeds primarily by attack on the carbonyl to yield the isocyanate with retention of configuration. • Substantial variations in Mo-NCO bond angle are observed in crystal structures of pure racemic and optically pure CpMo(NO)(η3-Methallyl)NCO. • Mixtures of isocyanate and azide complexes can yield X-ray structures with apparently anomalous bond metrics. • Mixtures of isocyanate and azide complexes in mixed crystals produce anomalies like bond stretch isomers and bond distortion isomers. The displacement of the iodide ligand in (+)-(Cp)Mo(NO)(η3-methallyl)I, (+)- 1 , by treatment with silver(I) isocyanate yields (+)-(Cp)Mo(NO)(η3-methallyl)(NCO), (+)- 2 , with retention of configuration at the metal and was found to have the S Mo configuration by X-ray crystallography. The X-ray data also showed the presence of two structure types in the unit cell of (+)- 2 , one bent and one linear with ∠MoNC bond angles of 154.4(4)° and 173.4(4)° respectively. In contrast, crystals of rac - 2 show only one structure in the solid with an intermediate angle of 165.7(4). If (+)- 2 is prepared via conversion of (+)- 1 first to the carbonyl, by abstraction of iodide and treatment with CO, and subsequently sodium azide, yielded crystals of (+)- 2 which showed varying angles ∠MoNC that appeared to be distortion isomers. Closer inspection of these products revealed an admixture of the intermediate azide compound, (+)-(Cp)Mo(NO)(η3-methallyl)N 3, (+)- 3 , in the sample that was predominantly (+)- 2. Mixtures of (+)- 3 and (+)- 2 or (-)- 3 and (-)- 2 -co-crystallize and the results of X-ray structures of such mixtures appear to show 2 with varying bond angles ∠MoNC depending on the percentage of 3 in them. For example crystals with 85% of (-)- 2 show ∠MoNC bond angles of 148.9(5)° and 171.9(5)°. This compares with the ∠MoNN in pure azide (+)- 3 of 123.7(6)° [Display omitted] [ABSTRACT FROM AUTHOR]

• The previously unknown Si-containing heterocycles, derivatives of 3-phenyl-2,3-dihydro-4 H -1,3,2-oxazasylin-4-one were obtained. • The procedures are experimentally simple and allow for the cost efficient synthesis of these hetrocycles. • The structure new Si-containing heterocycles was proved by NMR and X-ray methods. The interaction of acetoacetanilide with diorganyldichlorosilanes Me 2 SiCl 2 , MePhSiCl 2 and Ph 2 SiCl 2 led to the formation previously unknown polyfunctional six-membered Si-containing heterocycles. Their structure was characterized by NMR, IR and X-ray crystallography. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Trichlorostannyl complexes [Ru(SnCl 3) (Cp')L] (2a-c) were prepared by treatment of optically active half-sandwich chlorocomplexes [RuCl(Cp')L] (1a-c) with an excess of SnCl 2.2H 2 O in ethanol. Treatment of trichlorostannyl complexes 2a-c with NaBH 4 afforded trihydridostannyl derivatives [Ru(SnH 3) (Cp')L] (3a - c) in moderated yields. Treatment of 2a-c with MgBrMe gave the trimethylstannyl complexes Ru(SnMe 3) (Cp')L (4a - c). Alkynylstannyl derivatives [Ru{Sn(C≡CPh) 3 }(Cp')L] (5a-c) were prepared by treatment of trichlorostannyl compounds 2a-c with an excess of LiC≡CPh in thf. All the complexes present optical activity. The complexes were characterized spectroscopically and by X-ray crystal structure determination of [RuCl(η5-C 5 Me 5)L] (1b) , [Ru(SnCl 3) (η5-C 5 Me 5)L] (2b) , and [Ru(SnCl 3) (η5-C 9 H 7)L] (2c). The influence of different ligands on the Ru P interaction in several complexes 1a-c , 2a-c and 3a-c was evaluated by DFT calculations. These calculations indicate that [SnCl 3 ]- has a stronger stabilization effect than [Cl]- and the same occurs between C 9 H 7 and C 5 Me 5. These relative stabilities combined with the distortion energies of the fragments produce a stabilizing effect in the Ru P bonds of complex 2c that is twice as strong as in the 1b complex. Graphical abstract Image 1 Highlights • Synthesis of optically active half-sandwich chloro, diphosphinite, stannyl ruthenium complexes. • Calculated NPA charges indicate high polarization of the Ru-P bonds. • X-ray crystal structure of [RuCl(η5-C5Me5)L], [Ru(SnCl3)(η5-C5Me5)L] and [Ru(SnCl3)(η5-C9H7)L] (L= (R,R)-(+)-1,2-[bis(diphenyl)phosphanyloxy]-1,2-diphenylethane). [ABSTRACT FROM AUTHOR]

Abstract Refluxing equimolar amounts of 1-ferrocenyl-1,3-butanedione (Fcacac) with BrRe(CO) 5 in THF yielded the labile solvent complex fac -Re(CO) 3 (THF)[κ2-O,O-FcC(O)CHC(O)Me] (1) in 80% isolated yield. 1 may also be prepared in quantitative yield using fac -BrRe(THF) 2 (CO) 3 as the starting rhenium complex. The THF molecule in 1 is replaced by H 2 O during chromatographic purification to furnish the corresponding aqua complex fac -Re(CO) 3 (H 2 O)[κ2-O,O-FcC(O)CHC(O)Me] (2) while the reaction of 1 with PPh 3 gives fac -Re(CO) 3 (PPh 3)[κ2-O,O-FcC(O)CHC(O)Me] (3). Treatment of 1 with the terminal alkynes phenylacetylene and methyl propiolate proceeds rapidly at room temperature to give the π intermediates fac -Re(CO) 3 (alkyne)[κ2-O,O-FcC(O)CHC(O)Me] [ 4 (PhC≡CH); 6 (MeO 2 CC CH)] that are not stable and undergo a 1,4-addition with regiospecific alkyne attack at the γ-methine site of the Fcacac moiety to afford fac -Re(CO) 3 [κ3-C,O,O-FcC(O)CH(E-PhC = CH)C(O)Me] (5) and fac -Re(CO) 3 [κ3-C,O,O-FcC(O)CH(Z-HC=CCO 2 Me)C(O)Me] (7). The solid-state structure for 5 and 7 was established by X-ray crystallography, and the computed mechanisms that account for the formation of these two products from 1 and alkyne are presented. 1 reacts with the internal alkyne dimethyl acetylenedicarboxylate (DMAD) to furnish the novel dimeric compound [ fac -Re(CO) 3 {FcC(O)CH 2 C(CO 2 Me)C(CO 2 Me)}] 2 (9). The structure of 9 confirms the linking of the monomeric fac -Re(CO) 3 {FcC(O)CH 2 C(CO 2 Me)C(CO 2 Me)} fragments through the intermolecular coordination of the ester oxygen atom associated with the α-carbomethoxy moiety of the E-metalated alkene; the latter moiety is traced to the initial DMAD insertion into the 6-membered metallocyclic ring in the π precursor fac -Re(CO) 3 (MeO 2 CC CCO 2 Me)[κ2-O,O-FcC(O)CHC(O)Me]. Graphical abstract Image 1 Highlights • Reactive solvent complex fac -Re(CO) 3 (THF)[κ2-O,O-FcC(O)CHC(O)Me]. • Regiospecific alkyne insertion in fac -Re(CO) 3 (alkyne)[κ2-O,O-FcC(O)CHC(O)Me]. • Alkyne dimerization in fac -Re(CO) 3 (DMAD)[κ2-O,O-FcC(O)CHC(O)Me]. The labile solvent complex fac -Re(CO) 3 (THF)[κ2-O,O-FcC(O)CHC(O)Me] (1) has been prepared and investigated in ligand substitution reactions. Terminal alkynes displace the THF ligand in 1 to afford the metalated alkenyl compounds fac -Re(CO) 3 [κ3-C,O,O-FcC(O)CH(alkenyl)C(O)Me]. The regiochemistry attendant in the formal 1,4-addition reaction has been explored by electronic structure calculations. [ABSTRACT FROM AUTHOR]

Abstract A number of mononuclear triphenylantimony(V) 3,5-di- tert -butylcatecholates of the type (6-AlkOCH 2 -3,5-DBCat)SbPh 3 functionalized with alkoxymethyl group in the 6th position of aromatic ring in catecholato ligand, where Alk = Me ( 1 ), Et ( 2 ), iPr ( 3 ), tBu ( 4 ), n-Hexyl ( 5 ), and binuclear bis-catecholate Ph 3 Sb(3,5-DBCat-CH 2 OCH 2 -3,5-DBCat)SbPh 3 ( 6 ) have been synthesized and characterized in details. The molecular structures of 1 ·0.5 (n-hexane), 2 , 3 , 4 , 5 ·2MeOH, 6 ·2 (n-hexane) and 6 ·acetone have been determined by means of single-crystal X-ray analysis. The presence of alkoxymethyl-group in catecholate ligand does not lead to its coordination to the central antimony atom. Complexes 1 – 4 and 6 possess pentacoordinated environment of the central antimony atoms varying from the trigonal bipyramidal to the distorted tetragonal pyramidal. In crystal, molecules of complexes 1 – 5 form pairs where the “C Ph –H … π-system” interactions were found. The coordination environment of the central antimony atom in 5 ∙2MeOH is a distorted octahedral with coordinated methanol; the second methanol molecule is fixed between thehydroxyl group of coordinated methanol and the oxygen atom of hexyloxymethyl-group in the 6th position of catecholate ligand through the intramolecular hydrogen bonding. The electrochemical oxidations of complexes 1 – 4 proceed as two one-electron oxidations (the quasireversible oxidation “catecholate/o-semiquinolate” and the irreversible oxidation “o-semiquinolate/o-benzoquinone”). The first half-wave potential (E1 1/2 ) depends weakly on the alkyloxy substituent in AlkO-CH 2 group due to a weak inductive effect of AlkO group to the catecholate aromatic ring through the methylene linker. For binuclear bis-catecholate 6 , the first redox stage is two-electronic quasi-reversible peak without the separation of two stages into two one-electron processes, which indicates the absence of the electronic interaction between the two catecholate fragments. Graphical abstract A series of new 6-substituted 3,5-di-tert-butylcatecholato complexes of triphenylantimony(V) based on 6-alkoxymethyl-3,5-di-tert-butylcatechols and o-benzoquinones (where alkoxy group is methoxy, ethoxy, isopropoxy, tert-butoxy, n-hexoxy functions) have been synthesized. Novel redox active catechol, o-benzoquinone ligands and triphenylantimony(V) catecholates have been characterized in details. The molecular structures of mono- and binuclear triphenylantimony(V) catecholates in crystal were determined using single-crystal X-ray analysis. The electrochemical behaviour of complexes and influence of alkoxy methyl group were studied by cyclic voltammetry. Image 1 Highlights • Mononuclear triphenylantimony(V) catecholates with additional functional group. • Binuclear bis-catecholate Ph 3 Sb(3,5-DBCat-CH 2 OCH 2 -3,5-DBCat)SbPh 3. • New functionalized 3,5-di- tert -butylcatechol and o-benzoquinone with AlkylOCH 2 group. • The weak influence of AlkOCH2 group on the first oxidation potential of complexes. [ABSTRACT FROM AUTHOR]

Abstract Tin selenide (SnSe and SnSe 2 ) nanostructures have been synthesized by a one-pot reaction involving thermolysis of diorganotinbis (5-methyl-2-pyridyl selenolates), [R 2 Sn{SeC 5 H 3 (Me-5)N} 2 ] (R = tBu ( 1 ), Et ( 2 ) or Me ( 3 )) in a high boiling coordinating solvent. The latter have been isolated by treatment of R 2 SnCl 2 with sodium 5-methyl-2-pyridyl selenolate. They were characterized by elemental analysis, NMR (1H, 13C, 77Se, 119Sn) spectroscopy and single crystal X-ray diffraction analysis. The phase and composition tunability of tin selenide nanostructures has been demonstrated by thermolysis of [tBu 2 Sn{SeC 5 H 3 (Me-5)N} 2 ] through proper choice of high boiling solvent. pXRD, SEM, TEM and EDS were used to investigate the phase purity, morphology and composition of nanostructures. The band gap of nanostructures as deduced from DRS was found to be in the range of 1.75–2.1 eV (direct) and 1.36–1.49 eV (indirect). The band gap values of the nanostructures are blue shifted relative to bulk material indicating quantum confinement. The nanostructures showed photo response which make them promising candidate for alternative low-cost photon absorber material. Graphical abstract Image 1 Highlights • Tin selenide nanostructures have been synthesised conveniently from organotin selenolate. • Subtle tuning of reaction conditions has been used to isolate SnSe and SnSe 2. • Air stable [R 2 Sn{SeC 5 H 3 (Me-5)N} 2 ] precursors for tin selenide have been developed. • SnSe 2 nanostructures are photo-responsive while SnSe is inert. [ABSTRACT FROM AUTHOR]

Abstract In exploring the suitability of tetraborylmethane precursors as C4− synthons, we have studied the limits of stepwise trimethylsilyl and trimethylgermyl substitutions on tetrakis (1,3-propanediolatoboryl)methane. In contrast to previous reports indicating minimal silylation of tetraborylmethanes, we have shown that organolithium-mediated deborylation-metalation methodologies readily proceed for up to two substitutions. This enables the synthesis of new borylmethane derivatives including (TMS) 2 CB(pg) 2 and (TMG) 2 CB(pg) 2 (pg = 1,3-propanediolate, TMS = trimethylsilyl, TMG = trimethylgermyl). While further base-activated deborylation attempts lead to protodeboronation, limited reactivity, or de-esterification of the boronate ester, increasing the degree of substitution imparts air- and water-stability to the boronate esters. Graphical abstract Diboryldisilyl- and diboryldigermyl- methanes were synthesized via stepwise deborylation-metalation of a tetraborylmethane. The new compounds were characterized by NMR spectroscopy and X-ray crystallography. The disubstituted compounds are air- and water-stable and can be readily purified by column chromatography. Image 1 Highlights • Diboryldisilyl- and diboryldigermyl-methanes were synthesized via stepwise deborylation-metalation of a tetraborylmethane. • The new compounds were characterized by NMR spectroscopy and X-ray crystallography. • The disubstituted compounds are air- and water-stable and can be readily purified by column chromatography. [ABSTRACT FROM AUTHOR]

A row of dimeric diisobutylaluminum aryloxides bearing different sterically crowded substituents in ortho-positions of the aryl ligand [(ArO)Al i Bu 2 ] 2 (ArO = 2- t Bu-C 6 H 4 O ( Al TBP ), 2-Me,6- t Bu-C 6 H 3 O ( Al MTBP ), 2,6- i Pr 2 -C 6 H 3 O ( Al DIPP ), 2-Ph-C 6 H 4 O ( Al PP ), 2,6-Ph 2 -C 6 H 3 O ( Al DPP ), 1-C 10 H 7 O ( Al N-1 )) was synthesized. The Molecular structures of Al MTBP , Al DIPP , Al PP , Al DPP , and Al N-1 have been determined by X-ray crystallography. All dimeric diisobutylaluminum aryloxides were tested as activators of rac -Et (2-MeInd) 2 ZrMe 2 in homopolymerization of ethylene, propylene, copolymerization of ethylene with propylene and terpolymerization of ethylene/propylene/5-ethylidene-2-norbornene. It was shown that only Al MTBP and Al DPP work as effective activators in all polymerization processes, with activity of Al MTBP system being significantly higher than that of Al DPP . The evaluation of dimerization energies of synthesized aryloxides by means of DFT calculations have shown Al MTBP and Al DPP to form the least stable dimers. The activation of rac -Et (2-MeInd) 2 ZrMe 2 was modeled as bonding of diisobutylaluminum aryloxide with zirconocene followed by the first insertion of ethylene into Zr + –Me bond. As per that model, DFT calculations demonstrated the process to be the most favorable for Al MTBP and Al DPP which well corresponds to experimental observations. [ABSTRACT FROM AUTHOR]

The synthesis of mono-nuclear β-pyridylenolate zinc complexes L 1 2 Zn ( 1 ) (L 1 = (2-C 5 H 4 N)–CH=C(CH 3 )–O–) and L 2 2 Zn ( 2 ) (L 2 = (2-C 5 H 4 N)–CH=C (2-CH 3 C 6 H 5 )–O–) were performed by the protonolysis of the corresponding β-pyridylenol bidentate ligands 1-(2-pyridinyl)-2-propanone (L 1 H) and 1-(2-methylphenyl)-2-(2-pyridinyl)-ethanone (L 2 H) with diethylzinc in a 2:1 M ratio, respectively. The unanticipated tetra-nuclear β-pyridylenolate zinc complex [L 1 2 Zn- μ -O (Et)ZnEt] 2 ( 3 ) was isolated by the reaction of L 1 H with an equiv. of ZnEt 2 and oxygenation with air. All the complexes were well characterized by single crystal X-ray crystallography. Complexes 1 – 3 were tested as an initiator for the ring opening polymerization (ROP) of ε-caprolactone and l -lactide. In the same conditions, 1 and 2 are shown inefficient for ROP due to the lack of suitable initiating group for polymerization, however, tetra-nuclear complex 3 is a highly active single-component initiator in the ROP of ε-caprolactone and l -lactide. Complex 3 was also researched for its catalytic activity in block (PCL- b -PLLA) and gradient (LA- grad -CL) copolymerization of ε-caprolactone and l -lactide. [ABSTRACT FROM AUTHOR]

Mixed μ -azido-Schiff-base palladacycles [Pd{ C , N - κ 2 -(4-R)C 6 H 3 CH = N-C 6 H 3 -2,6- i -Pr 2 }( μ 2 -N 3 )] 2 (R = H, 1 ; OMe, 2 ) served as a metal-template for the synthesis of unusual dicarbodiimido bridged complexes [( μ 2 -NCN-Xyl)Pd{ C , N - κ 2 -(4-R)C 6 H 3 CH = NC 6 H 3 -2,6- i -Pr 2 }] 2 (R = H; OMe) and mixed tetrazolato-isocyanido complexes [Pd( C , N - κ 2 -(4-R)C 6 H 3 CH = NC 6 H 3 -2,6- i -Pr 2 )(CN 4 -Xyl)(CN-Xyl)] (R = H; OMe). Reactions of ethyl isothiocyanate with 1 and 2 gave the ditetrazole-thiolato bridged Pd complexes [( μ 2 -SCN 4 -C 2 H 5 )Pd( C , N - κ 2 -(4-R)C 6 H 3 CH = NC 6 H 3 -2,6- i -Pr 2 )] 2 . All these complexes were fully characterized by FT-IR, NMR spectroscopy, elemental analysis and/or X-ray crystallography. [ABSTRACT FROM AUTHOR]

Five diiron ethanedithiolate complexes bearing acetate ester have been prepared and characterized. Esterification of complex [{ μ -SCH 2 CH(CH 2 OH)S}Fe 2 (CO) 6 ] ( 1 ) with acetic acid in the presence of N , N ′-dicyclohexylcarbodiimide and 4-dimethylaminopyridine gave the acetate ester [{ μ -SCH 2 CH(CH 2 O 2 CCH 3 )S}Fe 2 (CO) 6 ] ( 2 ) in 94% yield. Further treatment of complex 2 with a monophosphine ligand triphenylphosphine, tricyclohexylphosphine, tris(2-methoxyphenyl)phosphine or tris(4-tolyl)phosphine in the presence of Me 3 NO·2H 2 O resulted in the formation of the corresponding monophosphine-substituted diiron derivatives [{ μ -SCH 2 CH(CH 2 O 2 CCH 3 )S}Fe 2 (CO) 5 L] (L = PPh 3 , 3 ; PCy 3 , 4 ; P(C 6 H 4 OCH 3 -2) 3 , 5 ; P(C 6 H 4 CH 3 -4) 3 , 6 ) (Cy = cyclohexyl) in 69–87% yields. The complexes 2 – 6 were characterized by elemental analysis and spectroscopy, together with X-ray crystallography. Furthermore, the electrochemical properties were investigated by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

The reaction of lithiated N,N-dimethylaniline π-coordinated to Cr(CO) 3 with W(CO) 6 and alkylation with [Et 3 O][BF 4 ] afforded the o -, m - and p -isomers of the σ,π-bimetallic complexes {η 6 -Me 2 NC 6 H 4 C(OEt)W(CO) 5 }Cr(CO) 3 ( o -, 1 , m -, 2 and p -isomer, 3 ). A by-product of the reaction is found by the substitution of a carbonyl ligand in 1 by the aniline nitrogen atom to give {η 6 -C,N- o -Me 2 NC 6 H 4 C(OEt)W(CO) 4 }Cr(CO) 3 ( 4 ). As a result, the W-chelate ring dominates the HOMO rather than the{η 6 -arene Cr(CO) 3 } fragment, affecting the site of the first oxidation. Enhanced activation of anisole by π-coordination to Cr(CO) 3 , and subsequent reactions with n BuLi, W(CO) 6 and [Et 3 O][BF 4 ] gave only o -substituted products {μ,η 6:1 - o -MeOC 6 H 4 C(OEt)W(CO) 5 }Cr(CO) 3 ( 5 ), the monocarbene chelate {μ,η 6:2 -C,O- o -MeOC 6 H 4 C(OEt)W(CO) 4 }Cr(CO) 3 ( 6 ) by carbonyl substitution, and by reaction of two molar equivalents of these reagents, the unique σ,π-heterotrimetallic biscarbene complex {μ 3 ,η 6:1:1 - o , o -MeOC 6 H 3 (C(OEt)W(CO) 5 ) 2 }Cr(CO) 3 ( 7 ). Attempts to synthesise the m - and p -isomers of 5 were unsuccessful due to transmetallation of the lithiated precursors. NMR data confirmed that lithiation and subsequent reactions of m - or p -bromoanisole chromiumtricarbonyl afforded only the o -isomer 5 and {η 6 -MeOC 6 H 5 }Cr(CO) 3 . Crystal structure determinations of complexes 1 – 7 confirmed their molecular structures. Spectroscopic data, electrochemistry studies and DFT calculations of the complexes are reported and are in line with a shifting of the HOMO from the Cr(CO) 3 to the W(CO) 4 chelate entity and with an unusually large delocalization of the HOMO of the other complexes onto the π-coordinated arene ligand and the carbene-bonded metal atom. [ABSTRACT FROM AUTHOR]

Reaction of O -trimethylsilyl ( O -TMS) derivatives of α-dimethylamino ketones with chloro(chloromethyl)dimethylsilane led to the formation of six-membered heterocyclic compounds with tetracoordinated silicon atom - 3,4-dihydro-2 H -1,4,2-oxazasilin-4-ium chlorides. The exchange reactions of 2,2,4,4-tetramethyl-6-phenyl-3,4-dihydro-2 H -1,4,2-oxazasilin-4-ium chloride were examined with Me 3 SiI and NaBPh 4 and the corresponding iodide or tetraphenylborate of 2,2,4,4-tetramethyl-6-phenyl-3,4-dihydro-2 H -1,4,2-oxazasilin-4-ium were isolated. 2,2,4,4-Tetramethyl-6-phenyl-3,4-dihydro-2 H -1,4,2-oxazasilin-4-ium chloride easy reacts with MeOH to give N -((methoxydimethylsilyl)methyl)- N , N -dimethyl-2-oxo-2-phenylethanaminium chloride. The structure of synthesized compounds 10 – 15 was proved by multinuclear NMR spectroscopy, 11 was also characterised by X-ray crystallography. [ABSTRACT FROM AUTHOR]

The three-component reactions of ArNHC(=Se)OCH 3 , Et 3 N and Fe 3 (CO) 12 afford the [Et 3 NH] + salt of the (μ-ArN=COCH 3 )Fe 2 (CO) 6 (μ-Se - ) cluster anion. The Se-centered cluster anion reacts with CH 3 I to give two pairs of isomers (μ-k 2 N,C-ArN=COR)Fe 2 (CO) 6 (μ-SeCH 3 ) ( 1 -e, 1 -a, Ar = C 6 H 5 ) and (μ-k 2 N,C-ArN=COR)Fe 2 (CO) 6 (μ-SeCH 3 ) ( 2 -e, 2 -a, Ar = 4-ClC 6 H 4 ). Furthermore, trapping the Se-centered cluster anion (μ-ArN=COR)Fe 2 (CO) 6 (μ-Se - ) with PPh 2 Cl offers (μ-k 2 N,C-ArN=COR)Fe 2 (CO) 6 (μ-k 2 Se,P-SePPh 2 ) ( 3 , Ar = C 6 H 5 , 5 , Ar = 4-ClC 6 H 4 , R = CH 3 ; 4 , Ar = C 6 H 5 , 6 , Ar = 4-ClC 6 H 4 , R = CH 2 Ph). Reactions of 1 with monophosphine L lead to the corresponding substituted complexes (μ-k 2 N,C-PhN=COCH 3 )Fe 2 (CO) 5 (L)(μ-SeCH 3 ) ( 7 -e, 7 -a, L = PPh 3 ; 8 -e, L = PPh 2 Py). All the new complexes have been completely characterized by elemental analyses, IR, 1 H NMR, 13 C NMR, and 31 P NMR spectroscopy and structurally determined by X-ray crystallography. Electrochemical studies reveal that when using HOAc or TFA as a proton source, all of the complexes can catalyze H 2 production. [ABSTRACT FROM AUTHOR]

The reactions of monoanionic tridentate alkylthiophenylazonaphthols featuring both C(sp 3 )–S and aryl C(sp 2 )–S bonds with low-valent group 9 metal compounds afforded monomeric metal complexes via either C(sp 2 )–S or C(sp 3 )–S cleavage. Rhodium(I) and iridium(I) selectively cleave C(sp 2 )–S bond of 2-hydroxy-1-(2′-alkylthiophenylazo) naphthalenes (HL 1 -HL 5 ) and 1-hydroxy-2-(2′-alkylthiophenylazo) naphthalenes (HL 6 -HL 10 ) with concomitant two-electron metal based oxidation resulting in the formation of novel M(III) cyclometallates. The molecular structures of the resulting complexes have been determined by single crystal X-ray crystallography. Rhodium(III) or iridium(III) binds desulfurized modified HL 1 -HL 10 ligands via O, N, C(aryl) donor set. Cobalt(I), the remaining member of the group 9, regiospecifically cleaves the C(sp 3 )–S bond of the diazene ligands with concomitant two-electron oxidation leading to the formation of novel cobalt(III) complexes. The molecular structures of one of the resulting cobalt(III) complex has been determined by single crystal X-ray crystallography. The cobalt(III) center binds one monoanionic ligand (HL) via O, N,S donor set along with a dianionic modified HL through O, N, S(thiolato) donor set. [ABSTRACT FROM AUTHOR]

Two seven-coordinate organotin complexes, namely, [(Me 2 Sn) ( μ -L) (4,4′-bipy) 0.5 (CH 3 OH) (DMF)] n ( 1 ) and [(Me 2 Sn) ( μ -L) (1,10-phen)] n ( 2 ) (H 2 L = 6,6′-dithionicotinic acid, 4,4′-bipy = 4,4′-bipyridine and 1,10-phen = 1,10-phenanthroline), were synthesized in a 1:1:1 M ratio reaction of Me 2 SnCl 2 , 6,6′-dithionicotinic acid and different N-donor ligands. Both complexes have been characterized by elemental analysis, IR, PXRD, TGA, and X-ray crystallography. The structural analysis reveals that complex 1 contains hexanuclear 78-membered macrocycles which further construct a 2D wavelike polymeric structure, while complex 2 displays 1D right-handed helical chain. Complex 1 is further linked into a 3D supramolecular architecture through the intermolecular C13-H13B⋯O2 interactions, and complex 2 is connected into a 2D supramolecular structure by the intermolecular C14-H14⋯N3 interactions. In such a system, both the μ -L 2 − anion ligand and nitrogen-containing ligands act as bipodal linkers facilitating the formation of metal-organic frameworks. [ABSTRACT FROM AUTHOR]

Ruthenium(II) complex namely [Ru(L 1 )(PPh 3 )Cl 2 ] ( 1 ) [where L 1  =  N -(pyridin-2-ylmethylene)quinolin-8-amine] derived from the tridentate ligand containing two pyridine and one imine donors was synthesized. This ruthenium(II) complex was treated with acidified nitrite solution to afford a ruthenium nitrosyl complex [Ru(L 2 )(PPh 3 )(NO)Cl](ClO 4 ) ( 2 ) [where L 2  =  N -(quinolin-8-yl)picolinamide]. These complexes were characterized by elemental analysis, electronic absorption, NMR ( 1 H and 31 P NMR) and IR spectral studies. The molecular structure of 2 was confirmed by X-ray crystallography and the redox property of metal centers was investigated. During nitrosylation of complex 1 , we found out the oxidation of imine functional group to amide functional group in the nitrosyl complex ( 2 ). Here, we also examined probable mechanism of nitric oxide (NO) mediated oxidation of imine to carboxamido group. The resultant nitrosyl complex 2 was found to be photoactive and could deliver NO on demand upon illumination of light. [ABSTRACT FROM AUTHOR]

A diastereoselective catalytic asymmetric hydrophosphination reaction was performed using a palladacycle catalyst to produce chiral PCP phosphine ligand with high dr (95:5) and excellent enantioselectivity (>99% ee). Subsequent facile metalation of the chiral ligand with Pt and Pd metal salts yielded the desired pincer complexes. The protonated form of these pincer complexes was also synthesised, and their structures were confirmed through the use of X-ray crystal diffraction and NMR spectroscopy analyses. [ABSTRACT FROM AUTHOR]