共查询到20条相似文献,搜索用时 15 毫秒
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Felix M. Mück Johannes A. Baus Dr. Christian Burschka Prof. Dr. Reinhold Tacke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5830-5834
The donor‐stabilized silylene [iPrNC(NiPr2)NiPr]2Si ( 2 ) reacts with PhEl?ElPh (El=S, Se) to form the respective cationic five‐coordinate bis(guanidinato)silicon(IV) complexes {[iPrNC(NiPr2)NiPr]2SiSPh}+PhS? ( 4 ) and {[iPrNC (NiPr2)NiPr]2SiSePh}+PhSe? ( 5 ). Compounds 4 and 5 were characterized by crystal structure analyses and NMR spectroscopic studies in the solid state. 相似文献
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The first silicon analogues of carbonic (carboxylic) esters, the silanoic thio‐, seleno‐, and tellurosilylesters 3 (Si?S), 4 (Si?Se), and 5 (Si?Te), were prepared and isolated in crystalline form in high yield. These thermally robust compounds are easily accessible by direct reaction of the stable siloxysilylene L(Si:)OSi(H)L′ 2 (L=HC(CMe)2[N(aryl)2], L′=CH[(C?CH2)‐CMe][N(aryl)]2; aryl=2,6‐iPr2C6H3) with the respective elemental chalcogen. The novel compounds were fully characterized by methods including multinuclear NMR spectroscopy and single‐crystal X‐ray diffraction analysis. Owing to intramolecular N→Si donor–acceptor support of the Si?X moieties (X=S, Se, Te), these compounds have a classical valence‐bond N+–Si–X? resonance betaine structure. At the same time, they also display a relatively strong nonclassical Si?X π‐bonding interaction between the chalcogen lone‐pair electrons (nπ donor orbitals) and two antibonding Si? N orbitals (σ*π acceptor orbitals mainly located at silicon), which was shown by IR and UV/Vis spectroscopy. Accordingly, the Si?X bonds in the chalcogenoesters are 7.4 ( 3 ), 6.7 ( 4 ), and 6.9 % ( 5 ) shorter than the corresponding Si? X single bonds and, thus, only a little longer than those in electronically less disturbed Si?X systems (“heavier” ketones). 相似文献
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Amitabha Mitra Dr. Joseph P. Wojcik Daniel Lecoanet Thomas Müller Prof. Dr. Robert West Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(22):4069-4072
SiSe matters : Diselenadisiletane 2 , formed from direct reaction of a racemic silylene 1 with elemental selenium, gives the first bis(silaselenone) upon hydrolysis with water ( 3 ; see picture, C gray, H white, N blue, O red, Se purple, Si green; d(Si?Se)=215 pm). The reaction is stereoconvergent: only racemic forms of 3 are obtained from a mixture of racemic and meso forms of 2 .
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Bastian Theis Dipl.‐Chem. Stefan Metz Dr. Christian Burschka Dr. Rüdiger Bertermann Dr. Stefan Maisch Reinhold Tacke Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(30):7329-7338
The neutral pentacoordinate silicon(IV) complexes 1 (SiS2ONC skeleton), 2 (SiSeSONC), 3 (SiTeSONC), 6 / 9 (SiSe2O2C), 7 (SiSe2S2C), and 8 / 10 (SiSe4C) were synthesized and structurally characterized by using single‐crystal X‐ray diffraction and multinuclear solid‐state and solution‐state (except for 6 – 9 ) NMR spectroscopy. With the synthesis of compounds 1 – 3 and 6 – 10 , it has been demonstrated that pentacoordinate silicon compounds with soft chalcogen ligand atoms (S, Se, Te) can be stable in the solid state and in solution. 相似文献
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From an Isolable Acyclic Phosphinosilylene Adduct to Donor‐Stabilized SiE Compounds (E=O,S, Se) 下载免费PDF全文
Kerstin Hansen Dr. Tibor Szilvási Dr. Burgert Blom Dr. Elisabeth Irran Prof. Dr. Matthias Driess 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):18930-18933
Reaction of the arylchlorosilylene‐NHC adduct ArSi(NHC)Cl [Ar=2,6‐Trip2C6H3; NHC=(MeC)2(NMe)2C:] 1 with one molar equiv of lithium diphenylphosphanide affords the first stable NHC‐stabilized acyclic phosphinosilylene adduct 2 (ArSi(NHC)PPh2), which could be structurally characterized. Compound 2 , when reacted with one molar equiv selenium and sulfur, affords the silanechalcogenones 4 a and 4 b (ArSi(NHC)(?E)PPh2, 4 a : E=Se, 4 b : E=S), respectively. Conversion of 2 with an excess of Se and S, through additional insertion of one chalcogen atom into the Si?P bond, leads to 3 a and 3 b (ArSi(NHC)(?E)‐E‐P(?E)Ph2, 3 a : E=Se, 3 b : E=S), respectively. Additionally, the exposure of 2 to N2O or CO2 yielded the isolable NHC‐stabilized silanone 4 c , Ar(NHC)(Ph2P)Si?O. 相似文献
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Philipp Willmes Dr. Michael J. Cowley Marco Hartmann Dr. Michael Zimmer Dr. Volker Huch Prof. Dr. David Scheschkewitz 《Angewandte Chemie (International ed. in English)》2014,53(8):2216-2220
The generation of heavier double‐bond systems without by‐ or side‐product formation is of considerable importance for their application in synthesis. Peripheral functional groups in such alkene homologues are promising in this regard owing to their inherent mobility. Depending on the steric demand of the N‐alkyl substituent R, the reaction of disilenide Ar2Si?Si(Ar)Li (Ar=2,4,6‐iPr3C6H2) with ClP(NR2)2 either affords the phosphinodisilene Ar2Si?Si(Ar)P(NR2)2 (for R=iPr) or P‐amino functionalized phosphasilenes Ar2(R2N)Si? Si(Ar)?P(NR2) (for R=Et, Me) by 1,3‐migration of one of the amino groups. In case of R=Me, upon addition of one equivalent of tert‐butylisonitrile a second amino group shift occurs to yield the 1‐aza‐3‐phosphaallene Ar2(R2N)Si? Si(NR2)(Ar)? P?C?NtBu with pronounced ylidic character. All new compounds were fully characterized by multinuclear NMR spectroscopy as well as single‐crystal X‐ray diffraction and DFT calculations in selected cases. 相似文献
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SiP Double Bonds: Experimental and Theoretical Study of an NHC‐Stabilized Phosphasilenylidene 下载免费PDF全文
Daniel Geiß Marius I. Arz Martin Straßmann Dr. Gregor Schnakenburg Prof. Dr. Alexander C. Filippou 《Angewandte Chemie (International ed. in English)》2015,54(9):2739-2744
An experimental and theoretical study of the first compound featuring a Si?P bond to a two‐coordinate silicon atom is reported. The NHC‐stabilized phosphasilenylidene (IDipp)Si?PMes* (IDipp=1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene, Mes*=2,4,6‐tBu3C6H2) was prepared by SiMe3Cl elimination from SiCl2(IDipp) and LiP(Mes*)SiMe3 and characterized by X‐ray crystallography, NMR spectroscopy, cyclic voltammetry, and UV/Vis spectroscopy. It has a planar trans‐bent geometry with a short Si? P distance of 2.1188(7) Å and acute bonding angles at Si (96.90(6)°) and P (95.38(6)°). The bonding parameters indicate the presence of a Si?P bond with a lone electron pair of high s‐character at Si and P, in agreement with natural bond orbital (NBO) analysis. Comparative cyclic voltammetric and UV/Vis spectroscopic experiments of this compound, the disilicon(0) compound (IDipp)Si?Si(IDipp), and the diphosphene Mes*P?PMes* reveal, in combination with quantum chemical calculations, the isolobal relationship of the three double‐bond systems. 相似文献
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Silicon–Oxygen Double Bonds: A Stable Silanone with a Trigonal‐Planar Coordinated Silicon Center 下载免费PDF全文
Prof. Dr. Alexander C. Filippou Dipl.‐Chem. Bernhard Baars Dr. Oleg Chernov Dipl.‐Chem. Yury N. Lebedev Dr. Gregor Schnakenburg 《Angewandte Chemie (International ed. in English)》2014,53(2):565-570
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Jason L. Dutton Gregory J. Farrar Michael J. Sgro Taylor L. Battista Paul J. Ragogna Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(39):10263-10271
The synthesis and comprehensive characterization of a series of base‐stabilized ChX2 (Ch=Se, Te; X=Cl, Br) is reported using aryl‐substituted diazabutadiene and 2,2′‐bipyridine (bipy) as the ligands. In stark contrast to free ChX2 the complexes display excellent thermal stability. Their use as viable ChX2 reagents that may be stored for later use is demonstrated in principle. The syntheses are simple and high‐yielding from commercially available or easily synthesized reagents. The bipy complexes are exceedingly rare examples of this ubiquitous ligand being utilized within Group 16 chemistry; the Se examples are the first to be characterized by X‐ray crystallography, and the Te species are only the second. 相似文献
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Uwe Herzog Uwe Böhme Gerd Rheinwald 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):281-286
The reactions of Me2MCl2 (M = Si, Ge, Sn), Si2Me4Cl2, Si2Me2Cl3, Si2Me2Cl4 and CH2(SiCl2Me)2, and suitable mixtures thereof, with H2S / NEt3 and Li2E (E = Se, Te) have been investigated and lead to a variety of new group 14 chalcogenide systems. 相似文献
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Dr. Goar Sánchez‐Sanz Dr. Cristina Trujillo Prof. Ibon Alkorta Prof. José Elguero 《Chemphyschem》2012,13(2):496-503
A theoretical study of the HTeXH (X=O, S, Se and Te) monomers and homodimers was carried out by means of second‐order Møller‐Plesset perturbation theory (MP2) computational methods. In the case of monomers, the isomerization energy from HTeXH to H2Te=X and H2X=Te (X=O, S, Se, and Te) and the rotational transition‐state barriers were obtained. Due to the chiral nature of these compounds, homo and heterochiral dimers were found. The electron density of the complexes was characterized with the atoms‐in‐molecules (AIM) methodology, finding a large variety of interactions. The charge transfer within the dimers was analyzed by means of natural bond orbitals (NBO). The density functional theory‐symmetry adapted perturbation theory (DFT‐SAPT) method was used to compute the components of the interaction energies. Hydrogen bonds and chalcogen–chalcogen interactions were characterized and their influence analyzed concerning the stability and chiral discrimination of the dimers. 相似文献
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Synthesis, Structures, and Reactivity of [(2,4,6-Ph3C6H2)Te(μ2-O)X]2 (X ? Br, I) [(2,4,6-Ph3C6H2)Te]2 reacts with iodine affording the aryltellurenic halide (2,4,6-Ph3C6H2)TeI, which is oxidized by oxygen to yield [(2,4,6-Ph3C6H2)Te(μ2-O)I]2. It crystallizes with two molecules of dichloromethane in the monoclinic space group P21/c with a unit cell of the dimensions a = 911.3(4); b = 1153.3(2); c = 2244.1(9) pm; β = 93.53(2)°, Z = 2). The analogues bromo compound [(2,4,6-Ph3C6H2)Te(μ2-O)Br]2 is obtained by the reaction of [(2,4,6-Ph3C6H2)Te(μ2-O)I]2 with NH4Br. It crystallizes with two molecules of xylene in the monoclinic space group P21/n (a = 1067.5(5); b = 1018.4(4); c = 2486.5(8) pm; β = 101.71(2)°; Z = 2). Both compounds are built up by two (2,4,6-Ph3C6H2)TeX units (X ? Br, I) which are linked by two oxgen bridges to form centrosymmetric molecules. The Te? O? Te angles are 102°. Distinct Te? O bond lengths have been found (191.4(2) and 208.6(2) pm in [(2,4,6-Ph3C6H2)Te(μ2-O)I]2 and 189.8(4)/208.4(5 pm in the bromo compound). 相似文献
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Novel Transition‐Metal (M=Cr,Mo, W,Fe) Carbonyl Complexes with Bis(guanidinato)silicon(II) Ligands 下载免费PDF全文
Felix M. Mück Dorit Kloß Johannes A. Baus Dr. Christian Burschka Prof. Dr. Reinhold Tacke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9620-9626
The donor‐stabilized silylene 2 (the first bis(guanidinato)silicon(II ) complex) reacts with the transition‐metal carbonyl complexes [M(CO)6] (M=Cr, Mo, W) to form the respective silylene complexes 7 – 10 . In the reactions with [M(CO)6] (M=Cr, Mo, W), the bis(guanidinato)silicon(II ) complex 2 behaves totally different compared with the analogous bis(amidinato)silicon(II ) complex 1 , which reacts with [M(CO)6] as a nucleophile to replace only one of the six carbonyl groups. In contrast, the reaction of 2 leads to the novel spirocyclic compounds 7 – 9 that contain a four‐membered SiN2C ring and a five‐membered MSiN2C ring with a M?Si and M?N bond (nucleophilic substitution of two carbonyl groups). Compounds 7 – 10 were characterized by elemental analyses (C, H, N), crystal structure analyses, and NMR spectroscopic studies in the solid state and in solution. 相似文献
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《Angewandte Chemie (International ed. in English)》2017,56(35):10486-10490
Preparation of two‐dimensional (2D) heterostructures is important not only fundamentally, but also technologically for applications in electronics and optoelectronics. Herein, we report a facile colloidal method for the synthesis of WOn ‐WX2 (n =2.7, 2.9; X=S, Se) heterostructures by sulfurization or selenization of WOn nanomaterials. The WOn ‐WX2 heterostructures are composed of WO2.9 nanoparticles (NPs) or WO2.7 nanowires (NWs) grown together with single‐ or few‐layer WX2 nanosheets (NSs). As a proof‐of‐concept application, the WOn ‐WX2 heterostructures are used as the anode interfacial buffer layer for green quantum dot light‐emitting diodes (QLEDs). The QLED prepared with WO2.9 NP‐WSe2 NS heterostructures achieves external quantum efficiency (EQE) of 8.53 %. To our knowledge, this is the highest efficiency in the reported green QLEDs using inorganic materials as the hole injection layer. 相似文献