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Crossed aldol reactions of the CF3-containing pseudo C2 symmetric cyclic imide 3 were carried out by way of the corresponding boron bisenolate to stereoselectively furnish the desired products 4 and this procedure allowed the preferential construction of the diastereomers of the compounds previously obtained from the acyclic counterpart 1. [ABSTRACT FROM AUTHOR]

A formal N-heterocyclic carbene insertion into the B–H bond of 9-BBN followed by a ring expansion reaction is reported. NHC-9-BBN adducts were reacted in one or two steps to give the corresponding di- or triazaborines. Hydride abstraction of selected species with [Ph3C]+ is facile, giving rise to 6π-aromatic cations with Lewis acidity comparable to Lewis acids commonly employed in frustrated Lewis pairs. [ABSTRACT FROM AUTHOR]

In this study, diamond crystals co-doped with boron and nitrogen were synthesized via a temperature gradient method at 5.3–5.8 GPa and 1300–1550 °C by adding B and N dopants to a system of carbon and an Fe-based solvent catalyst. The obtained co-doped diamond crystals were characterized via optical microscopy (OM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Our results indicated that the obtained B/N-co-doped diamond crystals were green in color and nearly transparent. The surface characteristics were different for the (100) and (111) crystal faces. In the B/N-co-doped diamonds, B, C, and N combined with each other and formed stable chemical bonds. The nitrogen concentration of the co-doped diamond crystals was much higher than that of the single doped crystals, and the form of nitrogen atoms was also different. The Raman characteristic peak of the co-doped diamond crystals almost did not shift as compared to that of the undoped or single doped crystals. [ABSTRACT FROM AUTHOR]

A homogeneous series of well-defined butadiynylene-BODIPY oligomers containing up to four BODIPY moieties have been synthesized from a “one-pot” oxidative homocoupling reaction of 2,6-di((trimethylsilyl)ethynyl)BODIPY. Further derivation of the resultant BODIPY dimer generates a water-soluble, red-emitting butadiyne-linked BODIPY dimer with pyridinium ions, which can ratiometrically detect viscosity, based on the two fluorescent conformers with the two BODIPY cores twisted and planar to each other depending on the viscosity of the environment. [ABSTRACT FROM AUTHOR]

We present the selective atom economical synthesis of borasiloxanes using a multi-component approach directly by the one-pot ruthenium catalysed reaction of boranes, silanes and water. [ABSTRACT FROM AUTHOR]

In this report, an efficient high-yield method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones via a three-component Biginelli reaction with various aldehydes, β-ketoesters/β-diketones and urea/thiourea is described. The reaction was catalyzed by sulfated polyborate under solvent free conditions at 100 °C. The catalyst was prepared and used as a Brønsted as well as Lewis acid catalyst. The catalyst was prepared by dehydration of boric acid followed by sulfonation and was characterized by different analytical techniques. The key advantages of the present method are the ability to tolerate a variety of functional groups, high yields, short reaction times, solvent free conditions, easy work-up, and recyclability of the catalyst, thus providing economical as well as ecological advantages. [ABSTRACT FROM AUTHOR]

A series of borocations have been synthesised from the addition of haloboranes to synthetically accessible N,N′-1,4-diazabutadiene precursors, which are derived from commercially available anilines. The synthesis and structural studies of the borocations are described. [ABSTRACT FROM AUTHOR]

The synthesis of novel dialkylboron guanidinates is reported: the symmetrical compounds, (Me2N)C(NR)2BR′2 [R = iPr, R′ = Nrb (1); R = Cy, R′ = Nrb (2); R = iPr, R′ = Cy (3); R = R′ = Cy (4); R = 2,6-iPr2-C6H3; R′ = Cy (5); Nrb = exo-2-norbornyl] and the asymmetrically coordinated {iPr(H)N}C(NiPr)(NAr)BCy2 [Ar = Ph (6), 4-Me-C6H4 (7), 4-tBu-C6H4 (8)] were prepared by the salt metathesis method from the appropriate lithium guanidinates and chloroboranes. Moreover, the bis(dicyclohexylboron)guanidinate(−2) {iPr(Cy2B)N}C(NiPr){N(4-tBu-C6H4)}BCy2 (9) was also prepared from the corresponding dilithium guanidinate Li2[{N(4-tBu-C6H4)}C(NiPr)2] and ClBCy2. The structures of compounds 1, 3, 6 and 9 were confirmed by X-ray diffraction and all displayed a chelate coordination of the guanidinate ligand to the BR′2 fragment, the latter displaying an additional BCy2 attached to the exocyclic N atom. Solutions of compounds 1–4 reached an equilibrium with the aminoboranes Me2NBR′2 [R′ = Nrb (10), Cy (11)] and the corresponding carbodiimides, which was slow at 25 °C. The thermodynamic parameters for these equilibria are also reported. The activation parameters for the equilibrium for compound 1 have been calculated after a kinetic study. Compounds 5–8, with one or two N-aryl fragments bound to a B centre, are more robust and need higher temperatures (80 °C) and prolonged times to give similar carbodiimide de-insertion reactions. [ABSTRACT FROM AUTHOR]

The condensation reactions of 2-formylindole (1) or 2-formylphenanthro[9,10-c]pyrrole (2) with various aromatic amines afforded the corresponding phenyl or phenanthrene ring fused mono-/bis-iminopyrrole ligand precursors 3–8, which, upon reaction with BPh3 in an appropriate molar ratio, led to the new mono- and diboron chelate compounds Ph2B[NC8H5C(H)=N-2,6-Ar] (Ar = 2,6-iPr2C6H39; C6H510), Ph2B[(NC8H5C(H)=N)2-1,4-C6H4]BPh211, Ph2B(NC16H9C(H)=N-Ar) (Ar = 2,6-iPr2C6H312; C6H513), and Ph2B[(NC16H9C(H)=N)2-1,4-C6H4]BPh214, respectively. Boron complexes 12–14, containing a phenanthrene fragment fused to the pyrrolyl C3–C4 bond, are highly fluorescent in solution, with quantum efficiencies of 37%, 61% and 58% (in THF), respectively, their emission colours ranging from blue to orange depending on the extension of π-conjugation. Complexes 9–11, containing a benzene fragment fused to the pyrrolyl C4–C5 bond, are much weaker emitters, exhibiting quantum efficiencies of 10%, 7% and 6%, respectively. DFT and TDDFT calculations showed that 2,6-iPr2C6H3N-substituents or, to a smaller extent, the indolyl group prevent a planar geometry of the ligand in the excited state and reveal the existence of a low energy weak band in all the indolyl complexes, which is responsible for the different optical properties. Non-doped single-layer light-emitting diodes (OLEDs) were fabricated with complexes 9–14, deposited by spin coating, that of complex 13 revealing a maximum luminance of 198 cd m−2. [ABSTRACT FROM AUTHOR]

Conjugated boron heterocycles have emerged as attractive synthetic targets due to their potential in medicinal chemistry and as electronic materials. However, the development of unsaturated boracycles has been hampered by difficulties in their preparation. Recently, a new synthetic avenue to access these species has been developed that takes advantage of the high reactivity of boroles. These five-membered anti-aromatic heterocycles can react with substrates to furnish ring expansion products via the insertion of one, two, or three atoms into the boracyclic ring. The ring expansion can occur via two pathways, the first exploits the activated diene moiety of the heterocycle in Diels–Alder chemistry with the resulting bicyclic species undergoing further rearrangements. The second reaction pathway is initiated by the coordination of the Lewis basic site of a substrate to the highly Lewis acidic boron center rendering the endocyclic B–C bond of the borole nucleophilic, inducing the formation of larger boracycles via attack at the electrophilic site of the substrate. This review summarizes the current state of this chemistry and details the mechanisms leading to the products. The methodologies described herein could very well be extended to other substrates, as well as applied to other anti-aromatic heterocycles. [ABSTRACT FROM AUTHOR]

The Ph2P-stabilized borenium 1 reacts cleanly with PhNH2, NH3 and HNTf2 to give a variety of boron compounds, namely the amino-substituted borenium 2 (substitution reaction at B), the neutral phosphine–borane 3, the mixed P/N-stabilized boronium 4 and the dicationic boron species 6. Remote modulation of the Lewis acidity at boron has been studied by preparing the related iPr2P-stabilized borenium 7 and reacting it with dihydrogen. [ABSTRACT FROM AUTHOR]

The thermal dehydrogenative coupling of aryl phosphine–borane adducts with iridium complexes bearing a bis(phosphinite) pincer ligand is reported. This catalysis produces high molecular weight poly(phosphinoboranes) [ArPH–BH2]n (Ar = Ph, pTol, Mes). Furthermore, we investigated the reactivity of these pincer complexes towards primary phosphines and their respective borane adducts on a stoichiometric scale. [ABSTRACT FROM AUTHOR]

The synthesis of a series of (formazanate)boron difluorides and their 1-electron reduction products is described. The neutral compounds are fluorescent with large Stokes shifts. DFT calculations suggest that a large structural reorganization accompanies photoexictation and accounts for the large Stokes shift. Reduction of the neutral boron difluorides occurs at the ligand and generates the corresponding radical anions. These complexes are non-fluorescent, allowing switching of the emission by changing the ligand oxidation state. [ABSTRACT FROM AUTHOR]

Two boron complexes coordinated with N,O-ligands based on oxadiazole were synthesized, and their structures, thermal behaviors, optical and electron transport properties were investigated in detail. The results demonstrate that both of the boron complexes could be used as deep blue emitting materials and excellent electron transporting materials. The electron mobilities, measured by the time-of-flight (TOF) technique, are 2.09 × 10−4 and 7.27 × 10−6 cm2 V−1 s−1. To understand their optoelectronic properties better, theoretical calculations of the electronic orbitals of the complexes were carried out. The energy levels and distribution of their lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) were investigated. The results illustrate that the LUMO of the boron complexes are favorable for electron transportation. [ABSTRACT FROM AUTHOR]

It has been demonstrated that the reaction of [2,2,2-(H)(PPh3)2-closo-2,1-RhSB8H8] (1) with PPh3 affords the boron substituted rhodathiaborane–PPh3 adduct, [6,6-(PPh3)2-9-(PPh3)-arachno-6,5-RhSB8H9] (2). Building upon this reaction, we report herein that the 10-vertex hydridorhodathiaborane 1 reacts with the Lewis bases, PCy3, py, 2-Mepy, 2-Etpy, 3-Mepy and 4-Mepy to form the rhodathiaborane–ligand adducts, [6,6-(PPh3)2-9-(L)-arachno-6,5-RhSB8H9], where L = PCy3 (3), 2-Mepy (4), 2-Etpy (5), py (6a), 3-Mepy (7a) or 4-Mepy (8a), and [8,9-μ-(H)-9-(PPh3)2-8-(L)-arachno-9,6-RhSB8H8], where L = py (6b), 3-Mepy (7b) or 4-Mepy (8b). The selectivity of the reactions depended on the nature of the entering Lewis bases, affording the 6,5-isomers, 2, 3, 4 and 5 as single products for PPh3, PCy3, 2-Mepy and 2-Etpy; and mixtures of the 6,5-/9,6-regioisomers, 6a/6b, 7a/7b and 8a/8b for py, 3-Mepy and 4-Mepy, respectively. The molecular structures of both regioisomers were characterized by X-ray diffraction analysis for the 6,5-isomers, 3 and 4, and for the 9,6-isomers, 7b and 8b. Variable temperature NMR studies of the reaction between 1 and PPh3 or 2-Mepy demonstrated that at low temperatures there is formation of the 9,6-species that subsequently isomerizes to the 6,5-regioisomer, indicating that for the more sterically hindered Lewis bases, PPh3, 2-Mepy and PCy3, the latter isomer is more stable and accessible through an intramolecular {Rh(PPh3)2} vertex flip. The formation of both isomers with py, 3-Mepy and 4-Mepy indicates that the kinetic and thermodynamic energies of the 6,5 and 9,6 rhodathiaborane–ligand adducts are similar for these Lewis bases. Lewis base bonding to exo-polyhedral boron vertices results in a change of the metal coordination from pseudo-octahedral Rh(iii) in 1 to pseudo-square planar Rh(i) in the adducts. The chemistry described here highlights the remarkable structural flexibility of these polyhedral boron-containing compounds, their modular architecture and their easy postsynthetic modification. [ABSTRACT FROM AUTHOR]

New borophosphates Li3Cs2M2B3P6O24 (M = Pb, Sr) have been synthesized by high-temperature solid-state reactions. The single-crystal X-ray diffraction data reveal their non-centrosymmetric cubic space group P213 and lattice parameters of a = 12.7246(3) Å and 12.687(2) Å and V = 2060.31(8) Å3 and 2042.3(4) Å3 for Li3Cs2Pb2B3P6O24 and Li3Cs2Sr2B3P6O24, respectively. They are three-dimensional (3D) [BP2O8]3−∞ anionic frameworks formed by a new double six-membered ring building unit consisting of BO4 and PO4 units joined alternately. Interestingly, such a double six-membered ring is regarded as the structural variation of the 12-membered ring in the known KSrBP2O8, fusing at the BO4 tetrahedron induced by the coexistence of the Li+ and Cs+ cations with their large size difference. The title compounds show weak SHG intensity and exhibit photoluminescence emissions at 410 nm for Li3Cs2Pb2B3P6O24 and 440 nm for Li3Cs2Sr2B3P6O24. [ABSTRACT FROM AUTHOR]

New borophosphates Li3Cs2M2B3P6O24 (M = Pb, Sr) have been synthesized by high-temperature solid-state reactions. The single-crystal X-ray diffraction data reveal their non-centrosymmetric cubic space group P213 and lattice parameters of a = 12.7246(3) Å and 12.687(2) Å and V = 2060.31(8) Å3 and 2042.3(4) Å3 for Li3Cs2Pb2B3P6O24 and Li3Cs2Sr2B3P6O24, respectively. They are three-dimensional (3D) [BP2O8]3−∞ anionic frameworks formed by a new double six-membered ring building unit consisting of BO4 and PO4 units joined alternately. Interestingly, such a double six-membered ring is regarded as the structural variation of the 12-membered ring in the known KSrBP2O8, fusing at the BO4 tetrahedron induced by the coexistence of the Li+ and Cs+ cations with their large size difference. The title compounds show weak SHG intensity and exhibit photoluminescence emissions at 410 nm for Li3Cs2Pb2B3P6O24 and 440 nm for Li3Cs2Sr2B3P6O24. [ABSTRACT FROM AUTHOR]

We report the synthesis and characterization of a photosensitizer containing boron-dipyrromethene and diarylethene. The photosensitizer has photo-controlled reversible photosensitivity and offers potential applications in photochemical catalysis and the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

A functional Cu(i) boron imidazolate framework (BIF) with a ladder-chain structure can not only change to another single-chain structure by incorporating 4,4′-bipyridine, but can also act as a reducing agent to load trimetal Au–Ag–Pd nanoparticles directly; the BIF with loaded noble NPs showed an excellent reduction effect on 4-nitrophenol. Moreover, we obtained a porous borocarbonitride by the direct carbonisation of this low-dimensional BIF. The resulting porous borocarbonitride exhibits fast adsorption behavior for 4-nitrophenol and can be a high-temperature conductor. [ABSTRACT FROM AUTHOR]

Boronate affinity molecularly imprinted polymer inverse opal particles were developed for the multiplex label-free detection of glycoproteins with high sensitivity and specificity. [ABSTRACT FROM AUTHOR]

The synthesis of the borondifluoride complex of a biscurcuminoid system is described, and its electrochemical and photophysical properties are compared to those of a series of monochromophoric models. The data show that the meta-linked biscurcuminoid exhibits enhanced optical properties in solution, such as high optical brightnesses obtained at one- and two-photon excitation (B1 = 87 000 M−1 cm−1 and B2 = 313 GM, respectively). UV/visible absorption of solid-state particles formed in water solution revealed that the four investigated dyes are strongly aggregated and fluorescence spectroscopy showed that they are emissive in the NIR with fluorescence quantum yields spanning from 1.5 to 12.5%. In the case of the meta-linked biscurcuminoid, a high brightness is obtained using one- and two-photon excitation (B1 = 6952 M−1 cm−1 and B2 = 70 GM, respectively). Such red-shifted emission combined with a yet significant brightness in the solid-state is believed to arise from the choice of the meta-linkage which limits strong intermolecular packing. [ABSTRACT FROM AUTHOR]

The synthesis and preliminary characterization of a boron-based 2D framework are presented. The peculiar electronic and morphological properties of this compound, together with its facile formation process, enable it to be used as a novel smart material for the design of electronic devices. [ABSTRACT FROM AUTHOR]

A stereoselective and electrocatalytic coupling reaction of isoeugenol has been reported for the first time in a 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)/boron-doped diamond (BDD) electrode system. This particular C–C bond formation and diastereoselectivity is driven by a solvate interaction between the radical species and another isoeugenol molecule. Due to an electrocatalytic cycle, only understoichiometric amounts of charge are necessary. Since electric current is directly employed as the oxidant, the reaction is metal and reagent-free. In addition, the electrolysis can be conducted in a very simple undivided beaker-type cell under constant current conditions. Therefore, the protocol is easy to use, suitable for scale-up, and inherently safe. [ABSTRACT FROM AUTHOR]

A series of bis-BODIPYs 1–6 bridged via thiophene, furan, N-alkylcarbazole, triphenyl-amine, para- and meta-phenylene groups have been synthesized and characterized by various spectroscopic techniques. The change in the spectroscopic properties of bis-BODIPYs upon varying the size of spacers was studied. X-ray crystal structures of three bis-BODIPYs containing triphenylamine, para- and meta-phenylene bridges were solved. Intermolecular C(H)…π and π…π stacking interactions were observed in solid state structures of three bis-BODIPYs. The dihedral angles between the spacer unit and two boron-dipyrrin units were lower in all three compounds as compared to their corresponding monomers. This suggests increased interactions between the two boron-dipyrrin units in molecules which are in turn reflected in the anodic shifts in their reduction potentials. DFT studies indicated effective electronic interactions between spacers and two boron dipyrrin units in all the bis-BODIPYs. The calculated HOMO–LUMO gap was found to be lower for bis-BODIPY having bulky carbazole spacers and higher for bis-BODIPY having smaller furan spacers. Changing the spacer size clearly affected the spectroscopic properties of the bis-BODIPYs and red shifted absorption and emission maxima were observed for bis-BODIPYs with furan and thiophene spacers as compared to bis-BODIPYs with phenylene or bulky aromatic spacers. [ABSTRACT FROM AUTHOR]

Novel boron fluorine complex molecules were designed and synthesized using the maleimide core moiety. Significant features such as a large Stoke shift, high quantum yield, and long range absorption and emission wavelengths were observed for these molecules. The lower LUMO level of these molecules indicates their potential application as electron transport materials. The optical band gap was calculated and compared by using UV-absorption edge, density functional theory and electrochemical studies, revealing the charge transfer characteristics. [ABSTRACT FROM AUTHOR]

Halogenated and alkoxylated closo-dodecaborates [B12X11OR]2− (X = Cl, Br; R = propyl, octyl, dodecyl) have been synthesized by halogenation of the known [B12H11OH]2− anion followed by alkylation in the superbasic medium DMSO/KOH. The obtained sodium salts were transformed by simple metathesis reactions in aqueous solution to the tetrabutylammonium ([NBu4]+) and 1-hexyl-3-methylimidazolium ([C6mim]+) salts. All compounds were fully characterized by heteronuclear NMR, IR and Raman spectroscopy, ESI mass spectrometry, and thermal analytical measurements. Selected anions were also structurally characterized as their [Ph4P]+ salts by single crystal X-ray diffraction. The [C6mim]+ salts are thermally stable up to more than 300 °C and show clear melting points. Surprisingly, the compound [C6mim]2[B12Cl11O-propyl] having the short propyl group bound to the boron cluster shows the lowest melting point (96 °C) of all the investigated compounds. Thus this compound is a rare member of the class of ionic liquids consisting of dianions. [ABSTRACT FROM AUTHOR]

BODIPY (boron dipyrromethene) derivatives and Ru(ii) complexes are two types of functional compounds that have found wide applications in the fields of biology and medicine. We herein synthesized two new Ru(ii) arene complexes based on an iodized BODIPY-containing pyridine (py-I-BODIPY) ligand, [(p-cym)Ru(bpy)(py-I-BODIPY)]2+ (2) and [(p-cym)Ru(2-pydaT)(py-I-BODIPY)]2+ (3), where p-cym = para-cymene, bpy = 2,2′-bipyridine, and 2-pydaT = 2,4-diamino-6-(2-pyridyl)-1,3,5-triazine. The photophysical, photochemical and photobiological properties of 2 and 3 were compared with that of [(p-cym)Ru(bpy)(py-BODIPY)]2+ (1). While 1 undergoes efficient monodentate ligand dissociation upon visible light irradiation and therefore may photobind DNA as a potential photoactivated chemotherapy (PACT) agent, 2 and 3 can generate 1O2 effectively and thus may serve as photosensitizers in photodynamic therapy (PDT). In electrophoresis experiments, 2 and 3 are even able to retard the mobility of plasmid DNA in the dark at high concentrations. More importantly, the cytotoxicities of 2 and 3 against human ovarian adenocarcinoma SKOV3 cells are enhanced about ten times under irradiation, leading to cytotoxicities more than one order of magnitude higher than that of cisplatin, demonstrating an efficient hybridization of the iodized BODIPY chromophore and the Ru(ii) arene complex. [ABSTRACT FROM AUTHOR]

A series of novel benzene centered mono-, bis- and tris-1,3,5-triazapentadiene ligands 6a–e was synthesized and investigated with respect to their reactivity towards triphenylborane. The resulting blue-fluorescent boron complexes 14a–e with a six-membered ring chelate structure show excellent thermal and chemical stability. All title compounds were completely characterized including X-ray diffraction studies for 14a–c and 14e. Whereas the absorption spectra of all three classes of compounds are similar, the fluorescence spectra show distinct differences. Thus, the emission spectra of 14a,b show Stokes shifts of 4100–6700 cm−1 with low quantum yields both in solution and in the solid state. However, the more bulky compounds 14c–e show markedly larger molar extinction coefficients and smaller bathochromic shifts compared to 14a,b. For all compounds, we observe significantly more intense red-shifted fluorescence in the solid state compared to that in dichloromethane solutions. For the interpretation of the absorption properties TD-DFT studies were performed based on DFT geometry optimizations. [ABSTRACT FROM AUTHOR]

Metallaheteroboranes are versatile compounds that can be conveniently modified and eventually tailored by ligand modification at either the metal centre or the boron vertices. Recently, we have discovered that protonation of some rhodathiaboranes affords cationic clusters with interesting reaction chemistry. In order to tune the reactivity of some of these polyhedral boron-based compounds, we have prepared air-stable orange [1,1-(η2-dppe)-3-(NC5H5)-closo-1,2-RhSB9H8] (2) by the treatment of the known hydridorhodathiaborane [8,8,8-(H)(PPh3)2-9-(NC5H5)-nido-8,7-RhSB9H9] (1) with dppe. The new 11-vertex rhodathiaborane, 2, reacts readily with triflic acid (TfOH) in CH2Cl2 to give orange cationic [8,8-(η2-dppe)-9-(NC5H5)-nido-8,7-RhSB9H9]+ (3). VT NMR experiments have allowed the characterization of a structural closo↑nido tautomerism, which involves hapticity changes in the ligation of the {SB9H9-(NC5H5)} moiety to the {Rh(dppe)} fragment, with the proton moving between the Rh(1)–B(3) and the B(9)–B(10) edges of the closo- and nido-isomers, respectively. The proton enhances the stereochemical non-rigidity and Lewis acidity of 3versus the neutral 2. This modification of the chemical and structural basis permits the efficient heterolytic splitting of the H–H bond, leading to the formation of new hydridorhodathiaborane isomers [8,8,8-(H)(η2-dppe)-μ-8,9-(H)-9-(NC5H5)-nido-8,7-RhSB9H10]+ (4) that are in equilibrium with the reactants, H2 and 3. [ABSTRACT FROM AUTHOR]

A new dual-boron-cored luminogen ligated with a nitrogen-containing multidentate ligand and four bulky phenyl rings was readily synthesized. The unique molecular structure endows this BN-containing luminogen with rich photophysical properties in either solution or in the solid state, including a large Stokes shift, aggregation induced emission activity and reversible piezochromism. Furthermore, this BN-containing luminogen exhibits good capabilities for imaging living cells and sensing of fluoride anions. [ABSTRACT FROM AUTHOR]

The frustrated Lewis pair comprised of B(C6F5)3 and a boryl–borate lithium salt Li[pinBB(Ph)pin] can efficiently activate dihydrogen, pinacolborane and ethylene at ambient temperature. Theoretical studies suggest that the nucleophilic sp2 boryl moiety of Li[pinBB(Ph)pin] plays different roles in these reactions. [ABSTRACT FROM AUTHOR]

This study is motivated by the recent discovery of the first all-boron fullerene analogue, a B40 cluster with D2d point-group symmetry, dubbed borospherene (Nat. Chem., 2014, 6, 727). Insight into the electronic structures and spectral properties of B40 is timely and important to understand the borospherene and the transition from open-ended plate or ribbon-like structures to a hollow-cage structure at B40. Optimized geometries of borospherene B40 for both the ground state and the first excited state allow us to compute spectral properties including UV-vis absorption, infrared (IR) and Raman spectra. Highly resolved absorption and emission spectra are obtained, for the first time, for the fullerene at the time-dependent density-functional theory (TD-DFT) level within the Franck–Condon approximation and including the Herzberg–Teller effect. Assigned vibrational modes in absorption and emission spectra are readily compared with future spectroscopy measurements to distinguish the hollow-cage structure of D2d-B40 from other quasi-planar boron structures. [ABSTRACT FROM AUTHOR]

This study is motivated by the recent discovery of the first all-boron fullerene analogue, a B40 cluster with D2d point-group symmetry, dubbed borospherene (Nat. Chem., 2014, 6, 727). Insight into the electronic structures and spectral properties of B40 is timely and important to understand the borospherene and the transition from open-ended plate or ribbon-like structures to a hollow-cage structure at B40. Optimized geometries of borospherene B40 for both the ground state and the first excited state allow us to compute spectral properties including UV-vis absorption, infrared (IR) and Raman spectra. Highly resolved absorption and emission spectra are obtained, for the first time, for the fullerene at the time-dependent density-functional theory (TD-DFT) level within the Franck–Condon approximation and including the Herzberg–Teller effect. Assigned vibrational modes in absorption and emission spectra are readily compared with future spectroscopy measurements to distinguish the hollow-cage structure of D2d-B40 from other quasi-planar boron structures. [ABSTRACT FROM AUTHOR]

An efficient route for the large scale synthesis of boron nitride (BN) micro-nano structures called nanosheet-assembled microwires is demonstrated for the first time, by annealing amorphous boron powder with ferric chloride (FeCl3) at elevated temperatures in flowing ammonia. The microwires have a very well-proportioned diameter of about 2 μm, while the nanosheets have an average thickness of less than 20 nm. The nanosheets are mostly separated with a bending and crumpling morphology and nearly vertically aligned to the microwire trunk. This micro-nano structure shows strong photoluminescence (PL) emission at 357 nm. It is revealed that FeCl3 reacts with B to generate BCl3, a vital vapor for the growth of BN micro-nano structures in addition to the provision of catalyst Fe. A combination growth mechanism of vapor–liquid–solid (VLS) and vapor–solid (VS) models is proposed to be responsible for the formation of this BN micro-nano structure. [ABSTRACT FROM AUTHOR]

A new domino strategy for selective synthesis of enaminones and their difluoroboron complexes through aryl migration has been developed. The reaction features low-cost and readily accessible starting materials, reliable scalability, and bond-forming efficiency as well as simple one-pot operation, which makes this strategy highly viable for future applications. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and X-ray analysis of dichloro- and dibromo-borenium cations stabilized by a 4-membered carbene are reported. The ligand's structural changes, atypical for similar systems, were caused by coordination to electron deficient fragments and its CN2P ring strain. [ABSTRACT FROM AUTHOR]

Triethylchalcogenostiboranes Et3SbvE (E = S 1, Se 2) were synthesized and their solid state structures were determined. The Sb-Se bond length is the shortest ever reported. Short Sb?E contacts were not observed. According to quantum chemical calculations, the bonding situation in 1 and 2 is best described as a polarized Sb-E single bond. [ABSTRACT FROM AUTHOR]

Heating a benzene solution of [η5-C2B9H10] Ta(NMe2)3 (1) in the presence of pyridine gave an unprecedented complex [η¹:η6-(Me2NCH2CH2)C2B9H10]Ta (NMe2)NC5H5(2). On the other hand, reaction of (η5-C2B9H11)TaMe3 with adamantly isonitrile (AdNC) in dimethoxyethane (DME) at room temperature afforded another unexpected complex (η6-C2B9H11)Ta[η³-C,C,N-CH2C(CH3)NAd](DME) (4). These results show that pyridine and DME are essential for the formation of 2 and 4, respectively. It is suggested that the n/do-η5-C2B9H10R2- ligand in tantallacarboranes takes up two electrons released by reductive elimination to form an arachno-η6-C2B9H10R4- fragment via the cage C-C bond cleavage. [ABSTRACT FROM AUTHOR]

A series of meso-pyridyl substituted BODIPY molecules has been synthesized, characterized and their optical and electrochemical properties compared. By utilizing ethanol and dichloromethane during the initial condensation reactions, there is a significant increase in the isolated yields compared to standard protocols. The properties of the highly fluorescent BODIPYs could be tuned by modifying the substituents of the pyridine, leading to pyridyl BODIPY as prospective ligands for future metal complexes. Furthermore, the presented BODIPY derivatives are shown to be applicable for fluorescence pH sensing over selective pH ranges. [ABSTRACT FROM AUTHOR]

A cubic cationic cage is rationally designed by using tridentate boron-imidazolate ligands to link tetrahedral metal Zn(ii) centers, which displays excellent properties in the Cr2O72− exchange and can reduce Au3+ ions into Au nanoparticles directly. [ABSTRACT FROM AUTHOR]

Two-electron reduction of bis(carbene) boronium salts allows for the preparation of unsymmetrically substituted nucleophilic boron derivatives of type (L1)(L2)BH, which are characterized by X-ray crystallography. A single electron reduction of the same starting materials leads to the corresponding boron-centered radical cations (L1)(L2)BH.+, X--. [ABSTRACT FROM AUTHOR]

A novel triarylboron compound, MPB, exhibiting reversible thermochromic dual-fluorescence in solid-state polymers and in liquid solvents was designed and synthesized. The fluorescent solid-state polymer with MPB can serve as a highly sensitive self-reference temperature indicator with a concentration independent feature. [ABSTRACT FROM AUTHOR]

The synthesis of boron-pyridyl-imino-isoindoline dyes, a novel type of BODIPY analogue, involves a facile and scalable two-step reaction. Broad envelopes of intense vibrational bands are observed for the main spectral bands in the absorption and emission spectra. High fluorescence quantum yields are obtained in solution, with significant intensity also observed in the solid-state. [ABSTRACT FROM AUTHOR]

Boron complexes of [14]triphyrins(2.1.1) were prepared from free-base [14]triphyrins(2.1.1) with phenylboron dichloride. The absorption spectrum of the meso-free β-alkyl–triphyrin boron complex in CH2Cl2 showed a broad weak band at around 640 nm assigned to transition from B-phenyl to the triphyrin, while that of the meso-aryl benzotriphyrin boron complex showed only Soret and Q bands. [ABSTRACT FROM AUTHOR]

BODIPY derivatives with one or two benzene units fused at different positions are prepared using novel synthetic methods. The resulting dye 1 shows deep red fluorescence with a large Stokes shift. Dyes 2 and 3 are reported for the first time and 3 exhibits near infrared absorption. The impact of benzannulation at different positions of BODIPY is discussed, and the geometry and electronic structure are studied by DFT calculations. [ABSTRACT FROM AUTHOR]