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1.
Prof. Soji Shimizu 《Angewandte Chemie (International ed. in English)》2023,62(10):e202217099
Because of the rich coordination chemistry and unique optical and electrochemical properties, porphyrin analogues have been intensively investigated. Among them, subporphyrins have been long-awaited molecules, with only their boron complexes known to date because of the crucial role of the central boron atom as a template in synthesis. The challenges related to the synthesis of a genuine subporphyrin (boron-free) have finally been met and reported in a recent article from Kim, Osuka, and Song. A key strategy of their synthesis lies in the introduction of an exocyclic double bond at the meso-position and subsequent reduction to obtain macrocyclic conjugation. Considering the fact that the development of porphyrin chemistry is ultimately linked to the availability of free base porphyrins, this seminal work will facilitate studies on coordination chemistry and applications in materials science. 相似文献
2.
Vargas G Hernández I Höpfl H Ochoa ME Castillo D Farfán N Santillan R Gómez E 《Inorganic chemistry》2004,43(26):8490-8500
Three types of homo- and heterotrinuclear boron complexes have been obtained in moderate to good yields from reactions of salen-type ligands with boric acid and combinations of boric acid with phenylboronic and phenylphosphonic acid. The products are air-stable and have relatively high melting points (>290 degrees C) but are poorly soluble or insoluble in common organic solvents. They have been characterized as far as possible by elemental analysis, mass spectrometry, IR, (1)H, (11)B, and (31)P NMR spectroscopy, and X-ray crystallography. Furthermore, theoretical calculations have been performed for representative examples to permit a complete comparison of the different structure types. A detailed analysis of the molecular structures showed that the complexes are constructed around a central B(3)O(3) or B(2)PO(3) ring. The salen ligands are attached to two boron atoms of these rings, which have therefore tetrahedral coordination geometries. The complexes contain seven- and eight-membered heterocycles of the B(2)C(n)ON(2) (n = 2, 3) type with chair or twisted-chair and boat-chair or chair-chair conformations, respectively. In the homotrinuclear complexes one of the three boron atoms is three-coordinate and can therefore still act as Lewis acid, thus making these products interesting for catalytic applications, e.g. in asymmetric synthesis. Depending on the substitutents attached to the boron atoms, these complexes show a relationship with either trimetaboric acid, boroxine, or the tetraborate dianion found in Borax. 相似文献
3.
Dr. Denis Frath Dr. Julien Massue Dr. Gilles Ulrich Dr. Raymond Ziessel 《Angewandte Chemie (International ed. in English)》2014,53(9):2290-2310
Multidisciplinary research on novel organic luminescent dyes is propelled by potential applications in plastic electronics and biomedical sciences. The construction of sophisticated fluorescent dyes around a tetrahedral boron(III) center is a particular approach that has fueled the creativity of chemists. Success in this enterprise has been readily achieved with simple synthetic protocols, the products of which display unusual spectroscopic behavior. This account is a critical review of recent advances in the field of boron(III) complexes (excluding BODIPYs and acetylacetonate boron complexes) involving species displaying similar coordination features, and we outline their potential development in several disciplines. 相似文献
4.
The structures and energies of the side-on complexes B2(N2)2 and monocyclic Bn(N2)nm (n = 3~6,m = -1~+2) between N2 (1∑+g) and B (2P) have been investigated by the DFT-B3LYP and MP2 methods at the 6-311+G(2d) and aug-cc-pVTZ levels. The analyses of NICS (Nucleus Independent Chemical Shifts),NBO (nature bond orbital),AIM (atoms in molecules) and frontal orbitals have been used to reveal the origin of coordination bond between the π-electron donor N2 group and B atom,accompanied by the comparison with the end-on complexes. The results have indicated that the side-on coordination complexes can be formed due to the relative strong fluidity of the π-electrons,and the nature of the coordination bond has been exposed to be that the N2 group offers 1πu electron to the 2p orbital of boron. The coordinate energies of the side-on complexes are less than those of the end-on complexes. Furthermore,the aromaticity of side-on coordination complex is weaker than that of the corresponding end-on coordination complex. 相似文献
5.
Reversible Reduction of Oxatriphyrin(3.1.1)—Adjusting the Coordination Abilities to the Central Ion 下载免费PDF全文
Dr. Miłosz Pawlicki Aneta Kędzia Dominik Bykowski Prof. Lechosław Latos‐Grażyński 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(52):17500-17506
Furan‐fused oxatriphyrin(3.1.1) acts as a ligand towards boron(III), phosphorous(III), and phosphorous(V) ions. The coordination abilities are adjusted by changes of the oxidation state. Two coordination modes are possible, depending on the central‐ion entrapped in the oxatriphyrin(3.1.1) environment. A free base, structurally similar to the complexes, can be easily obtained by regioselective reduction. The resulting molecules are highly emissive after conversion into a phlorin‐like oxatriphyrin(3.1.1) frame (NON donors), and show chiral activity caused by the presence of a tetrahedral carbon. 相似文献
6.
Kota Sato Tatsuo Goto Susumu Iwabuchi Hidefumi Hirai 《Journal of polymer science. Part A, Polymer chemistry》1993,31(3):763-768
The geometrical and electronic structures of the binary radical complexes of 2-methoxycarbonyl propyl radical with boron trichloride and with boron trifluoride were determined by using an ab initio molecular orbital method. The 2-methoxycarbonyl propyl radical complex was a model of the growing radical end in the copolymerization of methyl methacrylate in the presence of boron halides. The most stable structure of the binary radical complex composed of 2-methoxycarbonyl propyl radical with boron trichloride was a twisted form in which the dihedral angle between the vinyl group and the ester group was 32°, while that of the binary radical complex composed of methyl methacrylate radical with boron trifluoride was a planar form as the free radical. The frontier orbital energy of 2-methoxycarbonyl propyl radical was lowered by 0.06 au by the coordination of boron trichloride, while that was lowered only by 0.02 au by the coordination of boron trifluoride. The polymerization mechanism was elucidated on the basis of these predictions. © 1993 John Wiley & Sons, Inc. 相似文献
7.
Günter Schmid 《Angewandte Chemie (International ed. in English)》1970,9(11):819-830
“True” metal-boron compounds have been known for about ten years. The bonding between the metal and boron atoms can vary widely in nature: Not only simple covalent bonds are encountered but also coordinate bonds and boron-metal multicenter bonds. Furthermore, π complexes of transition metals with boron-nitrogen systems and metal complexes containing boron(I) compounds as ligands have recently also been prepared. 相似文献
8.
Careri M Elviri L Lanfranchi M Marchiò L Mora C Pellinghelli MA 《Inorganic chemistry》2003,42(6):2109-2114
Preparations of copper(I) and bismuth(III) complexes of hydrotris(4-ethyl-3-methyl-5-thioxo-1,2,4-triazolyl)borate (Tr(Et,Me)) are described. These complexes have been characterized by means of spectroscopy and microanalysis. Molecular structures of [Cu(Tr(Et,Me))](2) x 2.5CH(3)CN x 0.5H(2)O (3a) and [Bi(Tr(Et,Me))(2)]NO(3) x 2CHCl(3) (4a) have been determined by single-crystal X-ray diffraction. In the centrosymmetric dimeric copper(I) complex, Tr(Et,Me) acts in the k(3)S,S',H:kS' ' coordination mode. The metal is found in a distorted trigonal geometry as the ligand exhibits an "S(3)-inverted" conformation at the boron center so that a weak [B-H.Cu] agostic interaction renders the overall coordination of the (3 + 1) type. On the other hand, in the bismuth complex, Tr(Et,Me) presents the k(3)S,S',S' ' coordination mode and the "S(3)-normal" conformation. The metal is found in a regular octahedral geometry bound by six thioxo groups of two ligands. Species distributions in solution have been studied using electrospray ionization mass spectrometry upon dissolution of 3a and 4a crystals in acetonitrile. Monomeric and polynuclear copper(I) complexes with different M:L ratios are present in solution, while for 4a only the monomeric species is present. 相似文献
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11.
A Soluble Dynamic Complex Strategy for the Solution‐Processed Fabrication of Organic Thin‐Film Transistors of a Boron‐Containing Polycyclic Aromatic Hydrocarbon 下载免费PDF全文
Kyohei Matsuo Dr. Shohei Saito Prof. Dr. Shigehiro Yamaguchi 《Angewandte Chemie (International ed. in English)》2016,55(39):11984-11988
The solution‐processed fabrication of thin films of organic semiconductors enables the production of cost‐effective, large‐area organic electronic devices under mild conditions. The formation/dissociation of a dynamic B?N coordination bond can be used for the solution‐processed fabrication of semiconducting films of polycyclic aromatic hydrocarbon (PAH) materials. The poor solubility of a boron‐containing PAH in chloroform, toluene, and chlorobenzene was significantly improved by addition of minor amounts (1 wt % of solvent) of pyridine derivatives, as their coordination to the boron atom suppresses the inherent propensity of the PAHs to form π‐stacks. Spin‐coating solutions of the thus formed Lewis acid–base complexes resulted in the formation of amorphous thin films, which could be converted into polycrystalline films of the boron‐containing PAH upon thermal annealing. Organic thin‐film transistors prepared by this solution process displayed typical p‐type characteristics. 相似文献
12.
E. A. Malinina V. V. Avdeeva L. V. Goeva N. T. Kuznetsov 《Russian Journal of Inorganic Chemistry》2010,55(14):2148-2202
This survey concerns the coordination ability of B
n
H
n
2− (n = 6, 10, 12) boron cluster anions and their derivatives in complex formation. Boron cluster anions form four types of compounds:
salts of organic cations and alkali-metal cations, including Cat2B
n
H
n
, where specific interactions can be observed between a cation Cat and a boron cluster anion; salts of protonated anions CatB6H7 and CatB10H11, analogues of Cat[MB
n
H
n
] complexes, where an extra hydrogen atom appears bound with the BBB face of a boron polyhedron and performs as a hard acceptor;
metal complexes with outer-sphere boron cluster anions where specific ligand-ligand interactions may be observed between a
boron cluster anion and an inner-sphere ligand; and true metal complexes with boron cluster anions that enter the inner coordination
sphere. The last case characterizes closo-hydroborate anions as polydentate ligands whose denticity can vary widely under the effect of substituents or other ligands
in the complex. 相似文献
13.
Chusaku Ikeda 《Tetrahedron letters》2009,50(26):3349-251
Novel boron-dipyrrins bearing an aryl group and a phenyloxy group linked directly to the boron center have been prepared in high yields from arylboronic acid. The unique coordination geometry around the boron was determined by an X-ray crystallographic analysis. The complexes showed a strong fluorescence, and alkylation of the OH group shifted the emission to a longer wavelength with a larger Stokes shift. 相似文献
14.
The products of reaction of α-hydroxyanthraquinones with boric acid are mixtures of 9,10-, 1,10 -, 1,4- and 1,5-quinoid tautomeric
complexes of boric acid and borate esters differing by the coordination bonds with carbonyl groups existing in the dynamic
equilibrium. The deepening of the reagents color in the presence of boron does not a result only of the complexation, but
in the accompanying shift of the tautomeric equilibria. 相似文献
15.
Albrett AM Conradie J Ghosh A Brothers PJ 《Dalton transactions (Cambridge, England : 2003)》2008,(33):4464-4473
The structures of a number of mono- and diboron corrole complexes have been optimized using DFT methods in order to establish regio- and stereochemical preferences for bonding of one or two boron atoms to the corrole macrocycle. The formulations of the complexes were suggested either from preliminary experimental results (to be reported elsewhere) or by analogy with related diboron porphyrin compounds. The computational results suggest for the monoboron corroles BF(2)(H(2)corrole) and BPhH(H(2)corrole) that the regioisomer in which the boron is bound to a dipyrromethene site adjacent to the bipyrrole is preferred over the other possible regioisomers in which boron coordinates either in the bipyrrole or in the dipyrromethene site opposite the bipyrrole. In the N-substituted corrole complexes there are only two possiblities and, for each complex, the regioisomer with boron in the dipyrromethene site adjacent to the bipyrrole is lower in energy. For all four monoboron complexes the stereoisomers in which boron and both its substituents are displaced out of the mean N(4) plane are more stable than the boron in-plane stereoisomers. These regio- and stereochemical preferences are rationalised by an analysis of the deformations to the corrole macrocycle and the geometry at the boron atoms. The lowest energy structures in all cases correspond to the least strained configurations. In addition, all four complexes show significant BFHN hydrogen bonding and BHHN dihydrogen bonding interactions, which are maximised in the lowest energy configurations for each structure, indicating that these are important additional stabilising interactions. Three different regioisomers, each with cisoid or transoid stereochemistry were optimised for the diboron complex PhBOB(corrole) which contains a bridging BOB group. The dipyrromethene/dipyrromethene isomer is more stable than either of the dipyrromethene/bipyrrole isomers and cisoid stereochemistry is preferred over transoid. This contrasts with porphyrin complexes containing BOB groups for which both stereochemical possibilities are observed, and reflects the contracted size of the corrole macrocycle. Three further diboron corroles were investigated, the diboranyl cation [B(2)(corrole)](+) and its one- and two-electron reduced derivatives B(2)(corrole) and [B(2)(corrole)](-). These calculations were undertaken to determine whether the site of reduction of [B(2)(corrole)](+) is likely to be the diboron moiety or the macrocycle. The B-B bond lengths do not shorten upon reduction and an analysis of the molecular orbitals of each species indicates that reduction will be most likely to occur at the macrocycle, offering a potential route to an example of the two-electron reduced corrole ligand, an analogue of the 20-electron isophlorin ligand observed in the corresponding reduced porphyrin complex B(2)(porphine). 相似文献
16.
Tracey M. McLean Deidre M. Cleland Samuel J. Lind Keith C. Gordon Prof. Shane G. Telfer Dr. Mark R. Waterland Dr. 《化学:亚洲杂志》2010,5(9):2036-2046
A recently reported new class of ruthenium complexes containing 2,2′‐bipyridine and a dipyrrin ligand in the coordination sphere exhibit both strong metal‐to‐ligand charge‐transfer (MLCT) and π–π* transitions. Quantitative analysis of the resonance Raman scattering intensities and absorption spectra reveals only weak electronic interactions between these states despite direct coordination of the bipyridyl and dipyrrin ligands to the central ruthenium atom. On the basis of DFT calculations and time‐dependent DFT (TD‐DFT), we propose that the electronic excited states closely resemble “pure” MLCT and π–π* states. Resonance Raman intensity analysis demonstrates that a large amplitude transannular torsional motion provides a mechanism for relaxation on the π–π* excited‐state surface. We assert that this result is generally applicable to a range of dipyrrin complexes such as boron–dipyrrin and metallodipyrrin systems. Despite the large torsional distortion between the phenyl ring and the dipyrromethene plane, π–π* excitation extends out onto the phenyl ring which may have important consequences in solar‐energy‐conversion applications of ruthenium–dipyrrin complexes. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(19):3139-3179
AbstractInverse coordination is an emerging novel chemical concept describing the formation of metal complexes in which the arrangement of acceptor and donor sites is opposite to that occurring in conventional coordination complexes. Inverse coordination complexes are formed around a non-metal species as central atom (ion or small molecule) surrounded by a number of metal atoms (ions) connected or not by internal bridging (intramolecular) linkers. This article illustrates the diversity of species described under this concept with structures in which the coordination center is nitrogen (mono- and poly-nitrogen moieties). 相似文献
18.
19.
Ojo WS Jacob K Despagnet-Ayoub E Muñoz BK Gonell S Vendier L Nguyen VH Etienne M 《Inorganic chemistry》2012,51(5):2893-2901
The synthesis and characterization (mainly by (19)F NMR and X-ray diffraction) of highly fluorinated aryl-4,5,6,7-tetrafluoroindazoles and their corresponding thallium hydrotris(indazolyl)borate complexes are reported [aryl = phenyl, pentafluorophenyl, 3,5-dimethylphenyl, 3,5-bis(trifluoromethyl)phenyl]. Thanks to N-H···N hydrogen bonds, the indazoles crystallize as dimers that pack differently depending on the nature of the aryl group. The thallium hydrotris(indazolyl)borate complexes Tl[Fn-Tp(4Bo,3aryl)] resulting from the reaction of aryl-4,5,6,7-tetrafluoroindazoles [aryl = phenyl, 3,5-dimethylphenyl, 3,5-bis(trifluoromethyl)phenyl] with thallium borohydride adopt overall C(3v) symmetry with the indazolyl groups bound to boron via their N-1 nitrogen in a conventional manner. When the perfluorinated pentaphenyl-4,5,6,7-tetrafluoroindazole is reacted with thallium borohydride, a single regioisomer of C(s) symmetry having one indazolyl ring bound to boron via its N-2 nitrogen, TlHB(3-pentafluorophenyl-4,5,6,7-tetrafluoroindazol-1-yl)(2)(3-pentafluorophenyl-4,5,6,7-tetrafluoroindazol-2-yl) Tl[F27-Tp((4Bo,3C6F5)*)], is obtained for the first time. Surprisingly, the perfluorinated dihydrobis(indazolyl)borate complex Tl[F(18)-Bp(3Bo,3C6F5)], an intermediate on the way to the hydrotris(indazolyl)borate complex, has C(s) symmetry with two indazolyl rings bound to boron via N-2. The distortion of the coordination sphere around Tl and the arrangement of the complexes in the crystal are discussed. 相似文献
20.
Verkerk U Fujita M Dzwiniel TL McDonald R Stryker JM 《Journal of the American Chemical Society》2002,124(34):9988-9989
A topologically unique, conformationally constrained tetradentate ligand system for polymetallic coordination chemistry has been developed: tetrakis(2-hydroxyphenyl)ethene (1a) and substituted derivatives. The design exploits the planarity of the tetraphenylethylene core to impart rigidity to the roughly square oxygen binding array, while maintaining a degree of conformational mobility associated with rotation about the aryl-ethylene carbon-carbon bonds. Tetrakis(2-hydroxyphenyl)ethene derivatives are designed to promote multiple metal bridging over chelating coordination modes. The ligand is synthesized from anisole or 4-tert-butylanisole in four steps via the 2,2'-dimethoxybenzophenone hydrazones 4a,b. The sterically hindered ortho-substituted tetraphenylethylene core is produced in high yield by acid-catalyzed decomposition of the corresponding diaryl diazomethane prepared in situ by oxidation of the hydrazone using nickel peroxide. Deprotection of the methyl ethers using boron tribromide gives tetrakis(2-hydroxyphenyl)ethene (1a), characterized by X-ray crystallography, and tetrakis(5-tert-butyl-2-hydroxyphenyl)ethene (1b). Sterically isolating substituents in the 3-position can be installed via Claisen rearrangement/hydrogenation, providing tetrakis(3-n-propyl-2-hydroxyphenyl)ethene (6) efficiently. To illustrate potential applications of this unprecedented ligand class, two coordination complexes are reported, including tetrakis(2-diethylaluminoxyphenyl)ethene (8), a structurally robust eight-membered-ring aluminum/oxygen crown complex characterized both in solution and in the solid state. 相似文献