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A diverse reactivity of Sb(iii) and Bi(iii) N,C,N pincer complexes toward K[BEt3H] is reported along with a remarkable epimerization of chiral E–E bonded compounds.

The oxidative addition of CF

A remarkable activation of the CC triple bond including its stoichiometric hydrogenation was achieved by N,C,N-coordinated pnictinidenes via an element–ligand cooperative mechanism.

The titled 2,1‐benzazaphosphole (1) (i. e. ArP, where Ar=2‐(DippN=CH)C6H4, Dipp=2,6‐iPr2C6H3) showed a spectacular reactivity behaving both as a reactive heterodiene in hetero‐Diels‐Alder (DA) reactions or as a hidden phosphinidene in the coordination toward selected transition metals (TMs). Thus, 1 reacts with electron‐deficient alkynes RC≡CR (R=CO2Me, C5F4N) giving 1‐phospha‐1,4‐dihydro‐iminonaphthalenes 2 and 3, that undergo hydrogen migration producing 1‐phosphanaphthalenes 4 and 5. Compound 1 is also able to activate the C=C double bond in selected N‐alkyl/aryl‐maleimides RN(C(O)CH)2 (R=Me, tBu, Ph) resulting in the addition products 7–9 with bridged bicyclic [2.2.1] structures. The binding of the maleimides to 1 is semi‐reversible upon heating. By contrast, when 1 was treated with selected TM complexes, it serves as a 4e donor bridging two TMs thus producing complexes [μ‐ArP(AuCl)2] (10), [(μ‐ArP)4Ag4][X]4 (X=BF4 (11), OTf (12)) and [μ‐ArP(Co2(CO)6)] (13). The structure and electron distribution of the starting material 1 as well as of other compounds were also studied from the theoretical point of view., The dualistic behavior of the titled 2,1‐benzazaphosphole, behaving as a heterodiene versus a hidden phosphinidene, has been theoretically predicted based on an NTR analysis. This spectacular feature has been proven chemically as well. Thus, it is able to participate in hetero‐Diels‐Alder reactions forming expected heterocycles, but it also serves as a 4e ligand, using two phosphorus electron lone pairs, bridging two transition metals (Au, Ag and Co).

The intramolecularly N→Sn coordinated stannylene L(Cl)Sn (1), where L is {2,6-(Me2NCH2)2C6H3}−, has been used as a ligand for silver(I) and gold(I) compounds. The reactions of 1 with AgX (X = OAc, ...

The reaction of acetylferrocene hydrazone or 1,1′-diacetylferrocene dihydrazone with PCl3 gives the corresponding azines as the only organometallic product. The separation of the hydrazone function with a 1,4-phenylene or propane-2,2-diyl spacer enables the preparation of new heterocyclic compounds [(2H-1,2,3-diazaphosphol-5-yl)-4-phenyl]ferrocene (2b) and [1-(2H-1,2,3-diazaphosphol-5-yl)-1-methyl-ethyl]ferrocene (2c) but in low yields. Using acetylated hydrazones, that do not undergo transformation into stable azine molecules, led to the synthesis of (2-acetyl-1,2,3-diazaphosphol-5-yl)ferrocene (5a) and 1,1′-bis(2-acetyl-1,2,3-diazaphosphol-5-yl)ferrocene (8) in up to 70% yield. N-Acylated compounds 5a and 8 are readily converted to (2H-1,2,3-diazaphosphol-5-yl)ferrocene (2a) and 1,1′-bis(2H-1,2,3-diazaphosphol-5-yl)ferrocene (9). Analogous reactions were utilized for the preparation of (2-acetyl-1,2,3-diazarsol-5-yl)ferrocene (10), (2H-1,2,3-diazarsol-5-yl)ferrocene (11), 1,1′-bis(2-acetyl-1,2,3-diazarsol-5-yl)ferrocene (12) and 1,1′-bis(2H-1,2,3-diazarsol-5-yl)ferrocene (13). Electrochemical studies on a series of new ferrocenes showed that the 2H-1,2,3-diazapnictol-5-yl substituent possesses weak electron-withdrawing ability which is enhanced by acetylation in the 2-position of such a heterocycle. We also observed the electroactivity of the 1,2,3-diazapnictolyl substituent as it could be irreversibly reduced at potentials from −1.97 to −2.93 V vs. the Fc0/+ couple. All prepared compounds have been fully characterized using spectroscopic methods and molecular structures of 2a, 2b, 2c, 5a, 8, 9 and 10 are reported.

The reactions of two equivalents of germylene [(i-Pr)2NB(N-2,6-Me2C6H3)2]Ge (1) with carbonyl compounds RC(O)R′ resulted in carbonyl functionality activation and the formation of 4-(R,R′)-1,2-digerma-3-oxa-cyclobutanes (R/R′ = Ph/CF3 (2) or C6F5/H (3)). Surprisingly, the analogous reaction of 1 with C6F5C(O)Me led to the insertion of the germanium atom into the C–F bond of the perfluorophenyl group, thus producing a spiro compound (4) with a germanium atom sharing 1,2-digerma-3,5-diaza-4-bora-cyclopentane and 1-germa-2,4-diaza-3-boracyclobutane rings. Furthermore, the reaction of 1 with 2e− donors was investigated. In the case of 4-dimethylaminopyridine (DMAP), an expected complex [(i-Pr)2NB(N-2,6-Me2C6H3)2]Ge(DMAP) (5) was isolated, but using t-BuNC resulted in the formation of germanium(IV) cyanide [(i-Pr)2NB(N-2,6-Me2C6H3)2]Ge(CN)(t-Bu) (6) as a result of C–N bond activation in the starting isocyanide. In contrast, mixing other isocyanides RNC (R = Cy or Ad) with 1 in solution led only to an equilibrium between the starting compounds and most probably the corresponding complexes [(i-Pr)2NB(N-2,6-Me2C6H3)2]Ge(CNR) (R = Cy (7a) or Ad (8a)) based on NMR studies. From these equilibrium mixtures, fortuitously, single crystals of digerma-spiro-complexes (7 and 8) containing two germanium atoms (one of them coordinated to a particular isocyanide) were obtained and structurally authenticated by the X-ray diffraction technique.

Novel hybrid ligands based on [1,2,3]-diazaphosphole (dap) were prepared and their coordination behaviour toward selected transition metals has been studied. The syntheses and spectroscopic properties of polydentate bis(5-t-butyl-[1,2,3]-diazaphosphol-2-yl)-dimethylsilane (BdapsH,tBu) and bis(4-methyl-5-ethyl-[1,2,3]-diazaphosphol-2-yl)-dimethylsilane (BdapsMe,Et) are reported. In zerovalent compounds of the type [M(CO)4(κ2-P,P′-BdapsR1,R2)] (R1 = Me, R2 = Et, M = Cr, Mo and W; R1 = H, R2 = t-Bu, M = W) and [Ni(κ2-P,P′-BdapsH,tBu)2] the ligand serves as a P,P′-donor, giving rigid six-membered chelate rings. BdapsMe,Et is also capable of behaving as an N,N′-chelator as confirmed by isolation of high-spin chelate complex [CoBr2(κ2-N,N′-BdapsMe,Et)]. The reaction of parent 2H-4-methyl-5-ethyl-[1,2,3]-diazaphosphole with NiBr2·DME yielded paramagnetic compound [NiBr2(κ-N-dap)2], where the dap heterocycle bonds with the nickel(II) centre via a 1-nitrogen donor atom in a distorted tetrahedral environment. All the studied complexes showing different coordination modes of the new ligands were fully characterized, including single-crystal X-ray diffraction analysis.

Treatment of N,C,N-chelated organopnictogen(I) compounds ArE (1-3) (Ar=2,6-(RN=CH)2 C6 H3 , E/R=As/Dmp (1), Sb/tBu (2), and Bi/tBu (3), where Dmp=2,6-Me2 C6 H3 ) with various electron-deficient alkynes RC≡CR' (R/R'=CO2 Me (DMAD), R/R'=H/CO2 Me, or R/R'=NC5 F4 ) affords different types of heterocyclic compounds. In these reactions, 1-3 act as hidden dienes and participate in hetero-Diels-Alder (DA) reactions, a feature that has been only rarely reported for heavier pnictogen compounds. In this way, reactions of 1 furnished the set of 1-arsanaphthalenes 4-6. The most likely mechanism involves two steps, that is, an arsa-DA reaction giving a 1-arsa-1,4-dihydro-iminonaphthalene, followed by CH→NH proton migration. In contrast, this reaction sequence terminates at the first step in the case of the antimony analogue 2, thus giving the 1-stiba-1,4-dihydro-iminonaphthalenes 7 and 8. Reactions of the bismuth congener 3 gave one of two products depending on the alkyne used. Reaction of 3 with DMAD gave 1-bisma-1,4-dihydro-iminonaphthalene 9, whilst its reaction with two equivalents of HC≡C(CO2 Me) gave bismacyclohexadiene (10). All compounds have been characterized by NMR, IR, and Raman spectroscopies and X-ray diffraction analysis. The experimental data were complemented by a computational study, including a description of the reaction profiles of the hetero-DA reactions and an assessment of the aromaticities of the heterocyclic naphthalene derivatives.

The in situ reduction of the N,C,N-chelated bismuth(III) chloride (ArBiCl2) (where Ar = 2,6-(Me2NCH2)2C6H3) with 2 equivalents of K[B(s-Bu)3H] produced an unstable bismuth(I) compound ArBi (1) that was trapped by its coordination toward suitable transition metal fragments. Using this strategy a set of complexes with Group 6 metal carbonyls was obtained, i.e. [ArBiM(CO)5] (1-M; where M = Cr, Mo, W). The treatment of 1 with [Fe2(CO)9] provided the expected complex [ArBiFe(CO)4] (1-Fe) along with [ArBi(Fe(CO)4)2] (1-Fe2) as a minor by-product. By contrast, the reaction of 1 with the dinuclear complex [Co2(CO)8] furnished ionic complex [(ArBi)2Co(CO)3][Co(CO)4] (1-Co). All compounds were characterized using 1H and 13C{1H} NMR, IR and Raman spectroscopy. Molecular structures of 1-Cr, 1-Fe, 1-Fe2 and 1-Co were determined by the help of single-crystal X-ray diffraction analysis.

N,C,N-Chelated pnictinidenes ArE [where E = As, Sb or Bi; Ar = 2,6-(tBuN[double bond, length as m-dash]CH)2C6H3] were used as ligands for the coordination of various gold(i) complexes. Thus, the reaction of ArE with [AuCl(Me2S)] gave complexes [AuCl(ArE)] [where E = As (1) or Sb (2)] that exhibited only limited stability in solution. By contrast, the reaction of ArBi with [AuCl(Me2S)] led to the immediate deposition of gold metal and the oxidation of the bismuth atom giving ArBiCl2. The treatment of a tetrameric gold alkynyl complex [Au(C[triple bond, length as m-dash]CPh)]4 with ArAs and ArSb gave ionic compounds [Au(ArAs)2]+[Au2(C[triple bond, length as m-dash]CPh)3]- [denoted as 3+[Au2(C[triple bond, length as m-dash]CPh)3]-] and [Au(ArSb)2]+[Au(C[triple bond, length as m-dash]CPh)2]- [denoted as 4+[Au(C[triple bond, length as m-dash]CPh)2]-], respectively. Finally, the reaction of ArE with the carbene gold(i) complex [Au(IPr)(MeCN)]+[BF4]- [where IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene, MeCN = acetonitrile] produced ionic complexes [Au(IPr)(ArE)]+[BF4]- [for cations: E = As (5+), Sb (6+) or Bi (7+)]. All complexes were characterized using 1H and 13C NMR, high mass accuracy electrospray ionization mass spectrometry (ESI-MS), IR and Raman spectroscopy and (except for 1) by single-crystal X-ray diffraction analysis. Furthermore, the structure and bonding of both neutral and ionic complexes with different coordination patterns have also been investigated in detail using a Density Functional Theory (DFT) computational approach.

A new iron(II) bispidine complex with increased solubility in various organic solvents has been prepared and characterized by the spectroscopic methods and the X-ray crystallography. In-depth infrared study together with mechanical tests demonstrated the excellent catalytic performance of the iron compound in autoxidation process and established it as the potent drier suitable for solvent-borne alkyd binders. This study further reports the 2D-correlation analysis of the time-resolved infrared spectra, which was used for the first time for detailed analysis of the autoxidation process mechanism.

A series of tri- and diorganotin(IV) nitrates and nitrites bearing the 2-( N,N -dimethylaminomethyl)phenyl-as a C,N -chelating ligand (L CN ) has been prepared and structurally characterized. Air-stable triorganotin(IV) nitrates and nitrites of the type L CN R 2 SnX (for X = NO 3 : R = n -Bu ( 1 ), R = Ph ( 2 ); for X = NO 2 : R = n -Bu ( 7 ), R = Ph ( 8 )) and (L CN ) 2 ( n -Bu)SnX (X = NO 3 ( 3 ), NO 2 ( 9 )) are monomeric both in solution and solid state with distorted trigonal bipyramidal geometry around the central tin atom. These species were prepared in biphasic systems (water/organic solvent) using AgNO 3 and NaNO 2 , respectively. Diorganotin(IV) dinitrates ( i.e. L CN ( n -Bu)Sn(NO 3 ) 2 ( 4 ), L CN PhSn(NO 3 ) 2 ( 5 ) and (L CN ) 2 Sn(NO 3 ) 2 ( 6 )) and dinitrites ( i.e. L CN ( n -Bu)Sn(NO 2 ) 2 ( 10 ), L CN PhSn(NO 2 ) 2 ( 11 ) and (L CN ) 2 Sn(NO 2 ) 2 ( 12 )) are monomeric species due to the bidentate bonding fashion of the nitrato, nitrito and/or L CN substituents. Compounds 4–6 and 10–12 were prepared under an inert atmosphere using AgNO 3 in acetonitrile and KNO 2 in THF/benzene mixture of solvents, respectively. All these extraordinary stable compounds have been characterized by IR and NMR spectroscopy. In addition, solid-state structures of 2 , 4 , 5 , 6 , 8 , 11 , 12 and one decomposition product of 10 ( i.e. [L CN ( n -Bu)Sn(NO 3 )(μ-OH)] 2 ; 4a ) were determined by the SC-XRD techniques.

The reaction of N,C,N -chelated pnictinidenes ArE(I) [where Ar = C 6 H 3 -2,6-(CH=N t -Bu) 2 , E = As ( 1 ) and Sb ( 2 )] with dimeric complexes [(COD)M(μ-Cl)] 2 (where COD = 1,5-cyclooctadiene, M = Rh or Ir) gave pnictinidene complexes [ArEM(Cl) (COD)] [where E = As, M = Ir ( 3 ) and E = Sb, M = Ir ( 4 ), Rh ( 6 )] that were characterized by the help of 1 H and 13 C NMR spectroscopy and in the case of 3 and 6 also with the single-crystal X-ray diffraction analysis. However, the complex [ArAsRh(Cl) (COD)] ( 5 ) could not be isolated and exists only in an equilibrium with starting compounds in solution. The treatment of other Rh(I) precursors, such as [(COT) 2 Rh (μ-Cl)] 2 (COT = cyclooctene), with 1 or 2 led to the rhodium (III) pincer complex ArRhCl 2 ( 7 ) as a results of a transmetalation. Complex 7 was completely characterized including the single-crystal X-ray diffraction analysis. Finally, the reactivity toward the rhodium(I) carbonyl complex [(CO) 2 Rh (μ-Cl)] 2 was studied. In the case of the stibinidene 1 , an insoluble material was obtained, while the arsinidine derivative cis -[ArAsRh(Cl) (CO) 2 ] ( 8 ) could be isolated and characterized by NMR and IR spectroscopy.

The aim of this work was to describe polyaniline salts synthesized and to assess the mechanical and anticorrosion properties of alkyd resin-based coating materials pigmented with them, in dependence on the pigment volume concentration and type. Polyaniline salts were prepared by oxidative polymerization in the solutions of inorganic (hydrochloric, phosphoric, and sulfuric) and organic (p-toluenesulfonic and 5-sulfosalicylic) acids. Polyaniline salts were characterized by thermal analysis and spectroscopic methods. Electrical conductivity was also measured by the van der Pauw method, and the molecular weight of the polyaniline was determined by gel permeation chromatography. Furthermore, the particle size of the solid salts was measured, and the morphology was studied by scanning electron microscopy. Subsequently, the parameters required to formulate pigmented organic coatings, i.e., density and critical pigment volume concentration were determined. A soybean oil-based fast drying alkyd resin of medium oil length was used as the binder for the organic coating material. Organic coatings containing the polyaniline salts at pigment volume concentrations 0%, 1%, 5%, 10%, and 15% were formulated and subjected to a standard accelerated cyclic corrosion tests. The organic coatings (paint films) were also subjected to mechanical tests and to the electrochemical test by potentiodynamic polarization studies.

The synthesis of the monomeric organogermanium(II) hydrides {(LGeH)M(CO)5} (M = Cr (4), W (5)) utilizing the C,N-chelated ligand L (L is [2-(CH2NEt2)-4,6-tBu2-C6H2]-) is reported. The stabilization of the GeH terminal bond in 4 and 5 is accompanied by the combination of the electronic and steric protection of the ligand L. The reactivity of the GeH terminal bond was also investigated and attempts to reduce the polar C≡N bond in tBuNC provided unexpected N-C bond cleavage reaction yielding organogermanium(II) cyanides {(LGeCN)M(CO)5} (M = Cr (6), W (7)) instead of hydrogermylation reaction

N,C,N-intramolecularly coordinated antimony(III) and bismuth(III) oxides (ArMO)2 [where Ar = [2,6-(Me2NCH2)2C6H3]−, M = Sb (1) or Bi (2)] reacted with 1,1′-ferrocenedicarboxylic acid fc(COOH)2 (fc = ferrocene-1,1′-diyl) under formation of corresponding carboxylates fc(COO)2SbAr (4) and [fc(COO)2BiAr]2 (5). Similarly, the treatment of fc(COOH)2 with tin(IV) carbonate ArSnPhCO3 (3) led to the carboxylate fc(COO)2Sn(Ph)Ar (6). All compounds were characterized by the help of multinuclear NMR, Raman, IR and UV–Vis spectroscopy and in the case of 4 and 5 using single-crystal X-ray diffraction analysis.

N,C,N-Chelated pnictinidenes ArE [where E = As (1), Sb (2) or Bi (3); Ar = C 6H 3-2,6-(CH=Nt-Bu) 2] were used as ligands for the coordination of transition metal carbonyls. Thus, the reaction of 1-3 with [M(CO) 5THF] (where M = Cr, W) or [Mo(CO) 5(Me 3N)] gave complexes [(ArE)M(CO) 5] [where E = As and M = Cr (1a), Mo (1b), W (1c); E = Sb and M = Cr (2a), Mo (2b), W (2c); E = Bi and M = Cr (3a), Mo (3b), W (3c)]. Analogously, the treatment of 1-3 with [Fe 2(CO) 9] resulted in the formation of the complexes [(ArE)Fe(CO) 4] [where E = As (1d), Sb (2d) or Bi (3d)]. All compounds were characterized by 1H and 13C NMR spectroscopy, Raman, IR and UV-Vis spectroscopy. The molecular structures of the majority of the compounds (except 1b and 1c) were also determined by the single-crystal X-ray diffraction analysis. Furthermore, the structure and bondingof the title compounds have also been thoroughly investigated using a computational approach.

The coordination behavior of the polydentate ligand bis(1,2,4-diazaphospholyl)methane (Bdapm) toward group 6 and group 10 metals has been studied. From the reaction with [W(CO)5(NMe3)], three species with different coordination patterns were isolated and characterized. Thus we proved that the polydentate Bdapm ligand could serve as a terminal κ-P, bridging μ2-P,P and chelating κ2-N,N ligand in the complexes [W(CO)5(κ-P-Bdapm)], {[W(CO)5]2(μ2-P,P-Bdapm)} and {W(CO)4(κ2-N,N-Bdapm)}, respectively. The κ2-N,N chelate bonding mode has been also detected in the molybdenum(II) and nickel(II) derivatives [Mo(η3-C3H5)(κ2-N,N-Bdapm)(CO)2Cl] and [Ni(acac)2(κ2-N,N-Bdapm)]. The reaction of Bdapm with [M(C,N-Ar)Cl] fragment sources [Ar = 2-(N,N-dimethylaminomethyl)phenyl or 2-(N,N-dimethylaminomethyl)ferrocenyl, M = Pd or Pt] gives unstable κ-P bonded species, which are readily converted to the multimetallic complexes {[M(C,N-Ar)Cl]2-μ2-P,P-Bdapm}. The different coordination modes of the Bdamp ligand in such compounds were easily distinguished by multinuclear NMR spectroscopy. The crystal structures of five transition metal complexes demonstrating the coordination variability of Bdapm are reported. On inspection of the acquired data it is evident that the stability of the studied species increases in the order of the binding modes κ-P

The 2,1-benzazaarsole (1) showed a diene-like reactivity towards selected alkynes RC≡CR (R=CO 2 Me, C 5 F 4 N) thus forming 1-arsa-1,4-dihydro-iminonaphthalenes 2 a and 3 a as hardly isolable intermediates, that underwent facile CH→NH proton migration leading to before elusive substituted 1-arsanaphthalenes 2 b and 3 b that could be completely structurally characterized.

Monomeric organogermanium(II) hydrides {(LGeH)M(CO) 5 } (M = Cr (1), W (2), L = [2-(CH 2 NEt 2 )-4,6-tBu 2 -C 6 H 2 ] – ) were treated with ortho-quinones and terminal alkyne HC≡CCO 2 Me to give {[(LH)Ge(κ 2 -O 2 -3,5-tBu 2 C 6 H 2 )]M(CO) 5 } (M = Cr (3), W (4)), {[(LH)Ge(κ 2 -O 2 -3,4,5,6-Cl 4 C 6 )]M(CO) 5 } (M = Cr (5), W (6)) and {[LGeCH=CH(COOMe)]Cr(CO) 5 } (11). These reactions proceeded as catalyst-free reductions of C=O and C≡C bonds. Experimental data demonstrated zwitterionic character of Ge(II) complexes 3–6, where the 1,3,2-benzodioxagermylenolato anion involving the GeO 2 C 2 five membered ring coordinates the M(CO) 5 fragment. This anionic part is compensated by the NHEt 2 counter cation that is part of ligand L. Reactions of 1 and 2 differ mutually in the case of reduction of HC≡CCO 2 Me. The experimental and theoretical data suggest that compound 1 reacts with HC≡CCO 2 Me to give vinyl germylene 11 as the product of the anti-Markovnikov cis-1,2-addition, while complex 2 is inactive. These results thus suggest that the reactivity of the terminal GeH bond may be tuned by its coordination to various transition metals.

In this study, the importance of Sb behavior under different pH conditions has been addressed with respect to its stabilization in aqueous solutions using Mg-Fe layered double hydroxides (LDHs). The Sb(V) adsorption onto Mg-Fe LDHs was performed at different initial Sb(V) concentrations and pH values (pH 5.5, 6.5 and 7.5). The removal rate and the maximal adsorbed amount increased with decreasing pH values. Moreover, the surface complexation modeling (SCM) predicted preferable formation of monodentate mononuclear and bidentate binuclear complexes on the Mg-Fe LDH surface. Spectroscopic (X-ray diffraction analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy) and microscopic (scanning electron microscopy and energy-dispersive X-ray spectroscopy) techniques were used to further specify the adsorption mechanisms. The influence of chemical adsorption, surface-induced precipitation of brandholzite Mg[Sb(OH)6]2·6H2O, formation of brandholzite-like phases and/or anion exchange was observed. Moreover, Sb(V) was nonhomogeneously distributed on the Mg-Fe LDH surface at all pH values. The surface complexation modeling supported by solid-state analyses provided a strong tool to investigate the binding arrangements of Sb(V) on the Mg-Fe LDH surface. Such a complex mechanistic/modeling approach has not previously been presented and enables prediction of the Sb(V) adsorption behavior onto Mg-Fe LDHs under different conditions, evaluating their possible use in actual applications.

Modified iron(II) bispidine complex was synthesized and characterized by analytical methods including crystal structure determination on single crystal. Catalytic activity of the title compound toward autoxidation process was established on alkyd resin of long oil length. The standardized mechanical tests as well as kinetic studies, performed on thin layers of alkyd coatings, revealed high activity at considerably lower concentrations than usual for commercial cobalt(II) 2-ethylhexanoate. Due to high solubility in non-polar solvents, title compound is applicable without necessity of pre-dissolution in a polar organic solvent as in case of parent [Fe(bispi)Cl]Cl. Železnatý komplex s modifikovaným bispidinovým ligandem byl připraven a charakterizován analytickými metodami, které zahrnovaly RTG analýzu na monokrystalu. Katalytická aktivita tohoto komplexu byla studována na alkydu dlouhé olejové délky.

The treatment of N,C,N-chelated antimony(III) and bismuth(III) chlorides [C6H3-2,6-(CH=NR)2]MCl2 [R = tBu and M = Sb (1) or Bi (2); R = Dmp and M = Sb (3) or Bi (4)] (Dmp = 2,6-Me2C6H3) with one molar equivalent of Ag[CB11H12] led to a smooth formation of corresponding ionic pairs {[C6H3-2,6-(CH=NR)2]MCl}+[CB11H12]– [R = tBu and M = Sb (7) or Bi (8), R = Dmp and M = Sb (9) or Bi (10)]. Similarly, the reaction of C,N-chelated analogues [C6H2-2-(CH=NDip)-4,6-(tBu)2]MCl2 [M = Sb (5) or Bi (6), Dip = 2′,6′-iPr2C6H3] gave compounds {[C6H2-2-(CH=NDip)-4,6-(tBu)2]MCl}+[CB11H12]– [M = Sb (11) or Bi (12)]. All compounds 7–12 were characterized with 1H, 11B and 13C{1H} NMR spectroscopy, ESI-mass spectrometry, IR spectroscopy, and molecular structures of 7–9 and 12 were determined by the help of single-crystal X-ray diffraction analysis. In contrast, all attempts to cleave also the second M–Cl bond in 7–12 using another molar equivalent Ag[CB11H12] remained unsuccessful. Nevertheless, the reaction between 7 (or 8) and Ag[CB11H12] produced unprecedented adducts of both reagents namely {[C6H3-2,6-(CH=NtBu)2]SbCl}22+[Ag2(CB11H12)4]2– (13) and {[C6H3-2,6-(CH=NtBu)2]BiCl}+[Ag(CB11H12)2]– (14) in a reproducible manner. The molecular structures of these sparingly soluble compounds were determined by single-crystal X-ray diffraction analysis.

Oxovanadium(IV) compounds, [VO( O , O -R 1 COCHCOR 2 ) 2 ] (R 1 = R 2 = Me; R 1 = Me, R 2 = Ph; R 1 = R 2 = Ph), were established as a new class of environmentally friendly primary driers for solvent-borne alkyd binder. The performed experiments clearly show that the catalytic activity of oxovanadium compounds is, in some terms, considerably higher than observed for commercial cobalt-based drier ( Co-Nuodex ). The detailed study of the drying process reveals several differences in mechanism of autoxidation. The enhanced activity at low concentrations together with very low overall toxicity imply the oxovanadium compounds as promising catalysts of autoxidation reactions implying a great perspective in paint-producing industry.

The reactivity of N,C,N-intramolecularly coordinated antimony(III) and bismuth(III) oxides (LMO)2 [where M = Sb 1, Bi 2 and L is an abbreviation for (2,6-Me2NCH2)2C6H3] with sterically demanding organoboronic acid DipB(OH)2 (where Dip = 2,6-i-Pr2C6H3) was studied. Stoichiometric reactions of 1 and 2 with DipB(OH)2 in 1:4 molar ratio gave compounds LM[OB(Dip) (OH)]2 (where M = Sb 3, Bi 4). Compounds 3 and 4 are in solution liable to further dehydration leading to the formation of six-membered heteroboroxine rings LM[OB(Dip)]2O (where M = Sb 5, Bi 6). Changing of the stoichiometry to 1(oxide):2(acid) led to the isolation of eight-membered heteroboroxine rings LM[OB(Dip)O]2ML (where M = Sb 7, Bi 8), but both compounds are unstable in solution and slowly decomposed to 5 (or 6) with concomitant elimination of oxides 1 (or 2). Studied compounds were characterized by the help of multinuclear NMR spectroscopy, IR spectroscopy and in the case of 5 by single-crystal X-ray diffraction analysis.

A boraguanidinato-stabilized germylene, [(i-Pr)2NB(N-2,6-Me2C6H3)2]Ge, reacts with alkynes RCCR selectively in a 2 : 1 molar ratio to afford 3,4-R,R′-1,2-digermacyclobut-3-enes 1a–e as the products of formal [2 + 2 + 2] cyclization [R/R′ = Me/Me (1a), Ph/Ph (1b), Ph/H (1c), t-Bu/H (1d) and Cy/H (1e)]. Ferrocenyl-substituted alkynes react similarly, yielding the corresponding ferrocenylated 3,4-R,R′-1,2-digermacyclobut-3-enes 2a–d [where R/R′ = Fc/H (2a), Fc/Me (2b), Fc/Ph (2c), and Fc/Fc (2d); Fc = ferrocenyl]. By contrast, only one of the triple bonds available in conjugated diynes RCCCCR is activated with the germylene, while the second one remains intact even in the presence of an excess of the germylene. The exclusive formation of 3,4-R,(CCR)-1,2-digermacyclobut-3-enes 3a–c [R = Ph (3a), t-Bu(3b), and Fc (3c)] was ascribed to a steric repulsion around the second triple bond. On the other hand, the reaction of the germylene with more flexible dialkyne fc(CCPh)2 (fc = ferrocene-1,1′-diyl) proceeded in the expected manner, producing compound 4, where both triple bonds are transformed into 1,2-digermacyclobut-3-ene rings by reaction with four equivalents of the germylene. All compounds were characterized by multinuclear NMR spectroscopy, Raman and IR spectroscopy, and in the case of 1a–c, 2a, 2c, 3a, 3b and 4, also by single-crystal X-ray diffraction analysis. The ferrocenyl substituted compounds were studied by cyclic voltammetry (CV). Finally, the plausible reaction pathway was studied for a model reaction of [(i-Pr)2NB(N-2,6-Me2C6H3)2]Ge with MeCCMe using DFT computations.

N,C,N-Chelated pnictinidenes ArE [where E = As (1), Sb (2) or Bi (3); Ar = C

A series of new acyl-functionalized molybdenum(II) complexes [(η3-C3H5)(η5-C5H4COR)Mo(CO)2] have been successfully synthesized and crystallographically characterized, and the relationship between the reactivity and electronic properties of these organometallic compounds has been studied in detail. The X-ray analysis revealed [(η3-C3H5)(η5-C5H4COCF3)Mo(CO)2] to exist as a rare endo conformer, the first time that this structure has been observed in the crystal lattice of a [(η3-C3H5)(η5-Cp′)Mo(CO)2] (Cp′ = substituted Cp) complex without any disorder. It has also been demonstrated that the derivatives bearing very strong electron-withdrawing acyl groups (e.g., -CHO, -COCF3) show different outcomes in the protonation reactions compared with the parent cyclopentadienyl compound or derivatives bearing less electron-withdrawing groups (e.g., -COMe, -COPh). This study has also revealed the increased reactivity of the formyl derivative [(η3-C3H5)(η5-C5H4CHO)Mo(CO)2] towards aromatic amines. An IR spectroscopic analysis revealed that the aldimine-functionalized products formed very quickly even under the mild conditions that fulfill the basic rules of click chemistry.

Allyl molybdenum complex [( η 3 -C 3 H 5 )( η 5 -C 5 H 5 )Mo(CO) 2 ] ( Mo-A ) was examined as a new drier for solvent-borne alkyd binder. The drying activity of pure Mo-A and the of combinations of Mo-A with cobalt(II) 2-ethylhexanoate ( Co-Nuodex ) was examined using standard methods for measurements of the drying time and hardness development of the alkyd film. The detailed study of the drying process was studied by time-resolved infrared spectroscopy on ethyl linoleate as well as on thin coating of alkyd binder.

The allyl molybdenum(II) complex bearing tetrafluoro-4-pyridyl substituted cyclopentadienyl ligand, [(η3-C3H5){η5-C5H3(C5F4N)}Mo(CO)2], was synthesized and characterized by analytical and spectroscopic methods. This compound was found to be suitable precursor for complexes of the type [{η5-C5H4(C5F4N)}Mo(CO)2(NNL)][BF4] where NNL is N,N-chelating ligand. The biological study has shown that these complexes are cytotoxic active toward human leukemia cells MOLT-4. The cytotoxicity strongly depends on nature of the coordinated N,N-chelating ligand. The compounds bearing 1,10-phenanthroline (phen) and 2,2′-biquinoline (bq) are only medium active while the complexes with 4,7-diphenyl-1,10-phenanthroline (4,7-Ph2-phen) and 5-amino-1,10-phenanthroline (5-NH2-phen) show considerably higher activity than cisplatin. This study further describe the X-ray structures of [(η3-C3H5){η5-C5H4(C5F4N)}Mo(CO)2], [(η3-C3H5){η5-C5H3(1,3-C5F4N)2}Mo(CO)2], [{η5-C5H4(C5F4N)}Mo(CO)2(phen)][BF4] and [{η5-C5H4(C5F4N)}Mo(CO)2(5-NH2-phen)][BF4].

The reaction of N,C,N-chelated stibinidene ArSb (1) (Ar=C6 H3 -2,6-(CH=NtBu)2 ) with selected N-alkyl/aryl-maleimides RN(C(O)CH)2 (R=Me, tBu, Ph) gave the addition products with bridged bicyclic [2.2.1] structure containing an antimony atom at the bridgehead position, fused with a 6-membered benzene and a 5-membered N-alkyl/aryl-pyrrolidine ring. These compounds were completely characterized. More importantly, additional studies showed that these reactions are reversible in solution, thereby representing an unprecedented reversible activation of a C=C bond by an antimony(I) compound.

The reaction of N,C-intramolecularly coordinated organoantimony(III) compound L2SbCl (1) (where L is [2-(2′,6′-i-Pr2C6H3)N CHC6H4]) with one molar equivalent of the K-selectride (K[B(s-Bu)3H]) gave compound LSb{2-[CH2N(2′,6′-i-Pr2C6H3)]C6H4} (2) containing five membered aza-stiba heterocycle. On the contrary, analogical reaction between the organobismuth(III) compound L2BiCl (3) and K-selectride gave only inseparable mixture of products. Reactions of 2 with selected acids HX resulted in the cleavage of the present Sb–N bond and formation of novel N,C-chelated compounds LSb(X){2-[CH2NH(2′,6′-i-Pr2C6H3)]C6H4} (where X = Cl (4), CH3COO (5), CF3COO (6), CF3SO3 (7) or FcCOO (8); Fc = ferrocenyl). Compounds 4–8 were characterized by the help of elemental analysis, electrospray ionization (ESI) mass spectrometry, multinuclear NMR spectroscopy, IR spectroscopy and in the case of 5 by the single-crystal X-ray diffraction analysis. The molecular structures of compounds LSb(X){2-[CH2NH(2′,6′-i-Pr2C6H3)]C6H4}·HX (where X = CF3COO (6a), CF3SO3 (7a)) were determined by the single-crystal X-ray diffraction analysis as well. Compounds 6a and 7a are most probably products of partial hydrolysis of compounds 6 and 7.

Reaction of Cp2VCl2 with α-amino acids bearing functional group in the side chain gives N,O-chelate complexes [Cp2V(N,O-aa)]Cl (aa = ser, thr, asp, glu, asn, gln, lys, arg). These complexes were studied by spectroscopic methods (ESR, IR and Raman). All prepared complexes contain amino acid ligand bonded via oxygen atom of carboxylic group and nitrogen atom of amino group in α-position giving five-membered chelate ring. We have observed that hydroxy, amine, carboxylic, amide and guanidinium groups present in α-amino acid ligand are not able to coordinate to the central vanadium atom.

Two selectively 18O-labeled phthalides containing 18O either in the carbonyl (i.e., C18O) or in the alkoxy group (i.e., OC–18O) of the lactone ring were prepared in good yields (ca. 70%) from the corresponding methyl 2-(bromomethyl)benzoate and its selectively C18O labeled derivative, respectively, using water-assisted cyclization. The reaction mechanism involving formation of a cyclic carboxonium bromide and its water-assisted decomposition to the lactone is proposed.

The mechanism of synthesis of [(η3-Ind′)(η5-Cp)Mo(CO)2] was studied on methyl-substituted derivatives (Ind′ = 2-MeC9H6; 4,7-Me2C9H5). It was observed that the initial step involving reaction with HCl gives dimeric chloride species [{(η5-Ind′)Mo(CO)2(μ-Cl)}2]. This outcome differs from the structure suggested in the literature. Furthermore, it was demonstrated by various examples that compounds of the formula [{(η5-Ind′)Mo(CO)2(μ-Cl)}2] are convenient starting materials giving [(η3-Ind′)(η5-Cp′)Mo(CO)2] through the reaction with appropriate cyclopentadienides. The variability of this method was demonstrated on several examples including weakly donating Cp ligands bearing strong electron-withdrawing functional groups [C5H4COOMe, (1,2-MeOCO)2C5H3, and 1,2-(tBuNHCO)2C5H3] as well as Cp ligands bearing a pendant amine arm (C5H4CH2CH2NMe2). Similar η3-indenyl complexes are formed when using other univalent six-electron ligands such as carbaborane (9-Me2S-7,8-nido-C2B9H10) or scorpionate (Tp, Tp*). The attempts ...

Trimethylsilylcyclopentadienes bearing alkoxysilyl functionality, C 5 H 4 (SiMe 3 )(SiMe 2 OR), where R is Me ( 2 ), i -Pr ( 3 ) and t -Bu ( 4 ), were prepared and characterized. Methoxy derivative 2 reacts with TiCl 4 giving unstable [Ti( η 5 -C 5 H 4 SiMe 2 OMe)Cl 3 ] ( 5 ), which is slowly transformed to chlorosilyl complex [Ti( η 5 -C 5 H 4 SiMe 2 Cl)Cl 3 ] ( 6 ) and a mixture of cyclopentadienyltitanium(IV) methoxides on heating. Fully alkoxylated derivatives of the type [Ti( η 5 -C 5 H 4 SiMe 2 OR)(OR) 3 ] [R = Me ( 7 ), i- Pr ( 8 ), t -Bu ( 9 )] and {Ti[ η 5 -C 5 H 4 SiMe(OMe) 2 ](OMe) 3 } ( 10 ), were synthesized in low-to-moderate yields from respective chlorosilylcyclopentadienyltitanium trichlorides. All prepared alkoxysilyl compounds were characterized by spectroscopic techniques including 29 Si NMR. Polymerization activity of 7 – 10 in the presence of methylaluminoxane was determined and compared with [TiCp(OMe) 3 ] and corresponding trimethylsilyl-substituted compounds [Ti( η 5 -C 5 H 4 SiMe 3 )(OR) 3 ], where R is Me, i -Pr and t -Bu. The highest conversion of styrene has been observed in systems based on [Ti( η 5 -C 5 H 4 SiMe 3 )(OMe) 3 ], [TiCp(OMe) 3 ] and [Ti( η 5 -C 5 H 4 SiMe 3 )(OBu t ) 3 ], respectively. The new alkoxysilyl compounds 7 – 10 have significantly lower activity of 500–1800 kg of polystyrene/(mol Ti mol styrene h). All prepared polystyrenes showed both high melting point and high degree of syndiotacticity as determined by DSC and NMR measurements.

The synthesis of N→M intramolecularly coordinated group 14 and 15 chalcogenites is reported. The N→Sn intramolecularly coordinated organotin(IV) carbonate L(Ph)SnCO3 (1), where L is the N,C,N-chela...

The reaction of stibinidene and bismuthinidene ArM [where Ar=C6 H3 -2,6-(CH=NtBu)2 ; M=Sb (1), Bi (2)] with transition metal (TM) carbonyls Co2 (CO)8 and Mn2 (CO)10 produced unprecedented ionic complexes [(ArM)2 Co(CO)3 ](+) [Co(CO)4 ](-) and [(ArM)2 Mn(CO)4 ](+) [Mn(CO)5 ](-) [where M=Sb (3, 5), Bi (4, 6)]. The pnictinidenes 1 and 2 behaved as two-electron donors in this set of compounds. Besides the M→TM bonds, the topological analysis also revealed a number of secondary interactions contributing to the stabilization of cationic parts of titled complexes.

Ferrocenes bearing acyl substituents in the cyclopentadienyl rings [Fe(η5-C5H4COR)(η5-C5H5)] and [Fe(η5-C5H4COR)2] (R = CH3, CF3 and Ph) were examined as new driers for solvent-borne alkyd binder. All studied ferrocenes were found to be active catalysts for cross-linking reaction of the alkyd. These iron(II) compounds give solid polymeric films with hardness and drying time comparable to the commercial cobalt(II) drier. Acetyl- and benzoyl-substituted ferrocenes show an excellent synergic effect with the cobalt drier giving hard polymeric films within short drying time. The kinetics of the alkyd autoxidation was followed by FTIR spectroscopy. Spin-trapping ESR technique has proven the important role of the ferrocenium cation upon decomposition of hydroperoxides by ferrocene-based driers. The peroxy and alkoxy radicals, appearing in drying process, were resolved by the new spin trap methyl-N-mesityl nitrone.

The reaction of PhBCl2 with 1H-1,2,4-λ3-diazaphosphole in the presence of NEt3 gives a new scorpionate ligand, phenyl-tris(1,2,4-diazaphospholyl)borate (PhTdap). The coordination behaviour of this ligand toward transition and non-transition metals has been comprehensively studied. In the thallium(I) complex, Tl(PhTdap), κ2-N,N bonding supported with intramolecular η3-phenyl coordination has been observed in the solid state. Tl(PhTdap) also shows unusual intermolecular π-interactions between five-membered diazaphosphole rings and the thallium atom giving infinite molecular chains in the crystal. In the square planar complex [Pd(C,N-C6H4CH2NMe2)(PhTdap)], κ2-bonded scorpionate has been detected in both solution and in the solid state. For other studied compounds with the central metal ion Ti(IV), Mo(II), Mn(I), Fe(II), Ru(II), Co(II), Co(III), Ni(II) and Cd(II), the κ3-N,N,N coordination pattern was observed. Electronic properties of PhTdap and its ligand-field strength were elucidated from UV-Vis spectra of transition-metal species. The CH/P replacement on going from tris(pyrazolyl)borate to the ligand PhTdap causes a slight increase in electronic density rendered to the central metal atom. The following order of ligand-field strength has been established: HB(3,5-Me2pz)3 < PhB(pz)3 < HB(1,2,4-triazolyl) < HB(pz)3 < PhB(1,2,4-triazolyl) < PhTdap. The crystal structures of ten metal complexes bearing the new ligand are reported. The possibility of PhTdap coordination through the phosphorus atom is also briefly discussed.

The reaction of the organoantimony and organobismuth oxides [LSbO] 2 (1) and [LBiO] 2 (2), where L = [2,6-(Me 2 NCH 2 ) 2 C 6 H 3 ] ― , with phenylphosphinic acid in a 1:4 molar ratio gave the molecular organoantimony and organobismuth phosphinates LM[OP(H)(O)(Ph)] 2 [M = Sb (3), Bi (4)]. Similarly, the reaction of 1 and 2 with H 3 PO 3 gave the secondary phosphites LM[OP(H)(O)(OH)] 2 [M = Sb (5), Bi (6)] or the fully deprotonated phosphite {LM[O 2 P(H)(O)]} 2 [M = Sb (7), Bi (8)] depending on whether the molar ratio of the starting materials was 1:4 or 1:2. The syntheses of novel mixed phosphinate-phosphite LSb[OP(H)(O)(OH)][OP(H)(O)(Ph)] (9), phosphonate-phoshinate LSb[OP(tBu)(O)(OH)][OP(H)-(O)(Ph)] (10) and phosphonate-phosphite LSb[OP(tBu)-(O)(OH)][OP(H)(O)(OH)] (11) compounds are also described. While the organoantimony compounds 3, 5 and 7 are stable in solution, the organobismuth congeners showed only limited stability in solution and underwent a redox process involving to the reduction of the bismuth ions, and oxidation of the phosphorus ions from the +III to +V oxidation state. The reaction pathway associated with the redox process was studied with the system bismuth oxide 2 + Ph 2 P(O)(H), which gave compound LBi[OP(O)(Ph) 2 ] 2 (14) as a result of the oxidation of the phosphorus ion. All compounds were characterized by elemental analysis, 1 H, 13 C and 31 P NMR spectroscopy and IR spectroscopy. The solid-state molecular structures of compounds 3, 5a {LM[O 2 P(H)(O)][(HO) 2 P(H)-(O)]} and 7 were determined by X-ray diffraction.