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Alternative Ligands. XXVI. M(CO)4 L-Complexes (M ? Cr, Mo, W) of the Chelating Ligands Me2ESiMe2(CH2)2E′ Me2 (Me ? CH3; E ? P, As; E′ ? N, P, As) The reaction of M(CO)4NBD (NBD = norbornadiene; M ? Cr, Mo, W) with the ligands Me2ESiMe2(CH2)2E′ Me2 yields the chelate complexes (CO)4M[Me2ESiMe2]) for E,E′ ? P, As, but not for E and /or E′ ? N. The NSi group is not suited for coordination because of strong (p-d)π-interaction. In the case of the ligands with E ? P or As and E′ ? N chelate complexes can be detected in the reaction mixture, but isolable products are complexes with two ligands coordinated via the E donor group. The new compounds are characterized by analytical and spectroscopic (IR, NMR, MS) investigations. The spectroscopic data are also used to deduce the coordinating properties of the ligands. X-ray diffraction studies of the molybdenum complexes (CO)4Mo[Me2ESiMe2(CH2)2AsMe 2] (E ? P, As) in accord with the observed coordination effects show only small differences between SiE and CE donor functions. Attempts to use the ligands Me2ESiMe2(CH2)2AsMe2 (E ? P, As) for the preparation of Fe(CO)3L complexes result in the fission of the SiE bonds and the formation of the binuclear systems Fe2(CO)6(EMe2)2 (E ? P, As) together with the disilane derivative [Me2Si(CH2)2AsMe2]2. 相似文献
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Co-ordinative Properties of Chelating Ligands of the Type Me2XSi(Me2)CH2XMe2 (X ? N and/or P; Me ? CH3) The reactions of the ligands L ? Me2XSi(Me2)CH2XMe2 (X ? N and/or P; Me ? CH3) with M(CO)6 and M(CO)4norbor (norbor ? norbornadiene) (M ? Cr, Mo), respectively, yield derivatives of the types M(CO)5L, M(CO)4L, and M(CO)4L2, respectively. M(CO)5L compounds are formed from the hexacarbonyls with Me2NSiMe2CH2PMe2, whereas the ligand Me2NSiMe2CH2NMe2 does not afford analogous derivatives under the same conditions. Even on substitution of the diene-ligand in M(CO)4norbor by Me2NSiMe2CH2PMe2 the chelate complexes M(CO)4NMe2SiMe2CH2PMe2 are not obtained, but the cis-disubstituted products M(CO)4[PMe2CH2SiMe2NMe2]2 with phosphorus acting as donor atom are produced. The ligands Me2PSiMe2CH2XMe2(X ? N, P) give the chelate complexes M(CO)4PMe2SiMe2CH2XMe2 in high yields. The new compounds were identified by analytical and spectroscopic (PMR, IR, mass spectra) methods. 相似文献
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Synthesis and Structure of MII[AuF4]2 (MII ? Cd, Hg) Cd[AuF4]2 and the isotypic compound Hg[AuF4]2, both are yellow, crystallize tetragonal in the space-group P4/mcc-D (No. 124) with a = 575.0/575.6 pm, c = 1034.8/1042.3 pm and Z = 2. The single-crystals were obtained by solid-state reactions in goldtubes. 相似文献
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Existence of Hg2XA (X ? Halide, A ? Anion ≠ Halide) and Hg2XY Compounds (X and Y Halide) Investigations in molten mercuric bromide HgBr2 [1, 2] and comparing considerations between mercuric and mercurous chemistry lead to the till now unknown or less investigated compounds Hg2XA and Hg2XY (X, Y halide; A anion ≠ halide). Using TGA and DTA measurements in order to improve the reaction conditions Hg2XClO4 salts could be synthesized, whereas the hydrogene sulfates Hg2XHSO4 are formed in concentrated sulfuric acid (crystalline, instable by solvent removing). Powder diagrams and spectrochemical investigations point our that the lattices of the isolated mixed halides Hg2BrCl, Hg2BrI, and Hg2ClI contain not only the pure molecules Hg2X2 and Hg2Y2 but also the mixed molecules Hg2XY. Final statements need X-ray investigations. 相似文献
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Novel structures of H2C?C?CLiX (X ? F, Cl) were determined using HF/STO-3G gradient method. Both of the carbenoids have two equilibrium structures, askew and linear forms, at the level of calculation. In the case X?F, the former is more stable, but in the case X=Cl, the latter is more stable. The frontier MOs are given and analyzed. 相似文献
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Atrane-analogous Compounds. III. Atrane-analogous Compounds of the Type Me2DCH2CH2OSi(Me)(OCH2 CH2)2 D′Me (I) and Type Me2DCH2CH2OSi(Me) OCH2CH22D″Me2 (II) (Me?CH3; D, D′, D″?N, P, As) Atrane analogous compounds I and II (Abb. 1) have been prepared by condensation reactions of trifunctional silanes RSiX3 (X?Cl, OEt, NMe2) with N-methyldiethanolamine, ß-chloroethanol, ß-dimethylaminoethanol, and ß-dimethylarsanoethanol according to eqn. (1) to (3) and reaction schemes of Figs. 2 and 3, respectively. For compounds of type I weak N→Si adduct bonding is indicated for the MeN-donor of the eight-membered ring by significant shifts of the MeNCH2 and OCH2 proton n.m.r. signals. For compounds of type II there is no n.m.r. evidence for D→Si interactions. In spite of equal Lewis acidity of the Si atoms differences in adduct formation are observed for cage, ring, and acyclic podand systems, which can be explained mainly by entropy effects connected to the formation of five-membered rings. 相似文献
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Silaethenes. III. Preparation and Spectroscopic Characterization of H2Si?CH2, D2Si?CH2, and Me(H)Si?CH2 H2Si?CH2 and D2Si?CH2 are formed together with ethene and propene by gas phase pyrolysis at low pressure (10?2–10?3 mbar) from the corresponding mono- or 1,3-disilacyclobutanes in good yield and are characterized by i.r. and mass spectroscopic methods. Formation of propene can be explained by following reactions of the silaethene intermediate using a “head-to-head” mechanism. H2Si?CH2 can be stored at ?196°C for several months and can be transferred by trap-to-trap distillation in a vacuum system. Similar results are obtained for . 相似文献
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On the Structural Chemistry of BaMg2X2 (X ? Si, Ge, sn, Pb) The new compounds BaMg2X2 (X ? Si, Ge, Sn, Pb) have been prepared and their structures have been determined. BaMg2Si2 and BaMg2Ge2 crystallize in the ThCr2Si2-type, BaMg2Sn2 and BaMg2Pb2 show two new atomic arrangements, which are layer variants of the former type. 相似文献
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I. Kovacs V. Balema A. Bassowa E. Matern E. Sattler G. Fritz H. Borrmann R. Bauernschmitt R. Ahlrichs 《无机化学与普通化学杂志》1994,620(12):2033-2040
Synthesis and Structure of Phosphinophosphinidene-phosphoranes tBu2P? P?P(Me)tBu2 1, tBu(Me3Si)P? P?P(Me)tBu2 2, and tBu2P? P?P(Br)tBu2 3 A new method for the synthesis of 1 and 2 (Formulae see ?Inhaltsübersicht”?) is reported based on the reaction of 5 with substitution reagents (Me2SO4 or CH3Cl). The results of the X-ray structure determination of 1 and 2 are given and compared with those of 3 . While in 3 one P? P distance corresponds to a double bond and the other P? P distance to a single bond (difference 12.5 pm) the differences of the P? P distances in 1 and 2 are much smaller: 5.28 pm in 1 , 4.68 pm in 2 . Both 1 and 2 crystallize monoclinic in the space group P21/n (Z = 4). 2 additionally contains two disordered molecules of the solvent pentane in the unit cell. Parameters of 1 : a = 884.32(8) pm, b = 1 924.67(25) pm, c = 1 277.07(13) pm, β = 100.816(8)°, and of 2 : a = 1 101.93(12) pm, b = 1 712.46(18) pm, c = 1 395.81(12) pm, β = 111.159(7)°, all data collected at 143 K. The skeleton of the three P atoms is bent (PPP angle 100.95° for 1 , 100.29° for 2 and 105.77° for 3 ). Ab initio SCF calculations are used to discuss the bonding situation in the molecular skeleton of the three P atoms of 1 and 3 . The results show a significant contribution of the ionic structure R2P? P(?)? P(+)(X)R2. The structure with (partially) charged P atoms is stabilized by bulky polarizable groups R (as tBu) as compared to the fully covalent structure R2P? P(X)? PR2. 相似文献
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On the RbNiCrF6 Type(1): On CsCuMF6 (M?NiIII, TiIII), CsMgMF6 (M ?Co, Fe, Ga), and CsZnMF6 (M?NiIII, CoIII, FeIII) New prepared are the cubic compounds CsCuNiIIIF6 (dark brown, a = 10.14 Å); CsZnNiIIIF6 (dark brown, a = 10.17 Å); CsCuTiIIIF6 (light grey, a = 10.39 Å); CsMgGaF6 (colourless, a = 10.23 Å); CsMgFeF6 (colourless, a = 10.53 Å); CsZnFeF6 (colourless, a = 10.42 Å); CsMgCoIIIF5 (light blue, a = 10.27 Å) and CsZnCoIIIF6 (light blue, a = 10.34 Å), all RbNiCrF6-type of structure. The Madelung part of lattice energy, MAPLE, is calculated and discussed. 相似文献
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Perfluoromethyl-Element-Ligands. XXXV. Reactivity of Metallated Phosphanes and Arsanes of the Type π-C5H5(CO)3MER2 (M ? Cr, Mo, W; E ? P, As; R ? CF3, CN) The influence of the complex fragments π-C5H5(CO)3M (M ? Cr, Mo, W) on the basicity of the metallated phosphanes or arsanes π-C5H5(CO)3MER2 (E ? P, As; R ? CF3, CN) has been investigated by reactions with sulfur, methyliodide, fluorotrichloromethane, and W(CO)5THF, respectively. π-C5H5(CO)3ME(CF3)2 (E ? P: 1a–c ; E ? As: 2a–c ) react with sulfur only for E ? P to give the complexes π-C5H5(CO)3P(S)(CF3)2 ( 5a–c ) in good yield. The attempted thermal transformation of the phosphane sulfides to η2 coordinated (CF3)2P?S complexes proves unsuccessful. The reactions of 1a–c, 2a–c and π-C5H5(CO)3MP(CN)2 ( 3a–c ) with CH3I or CCl3F do not lead to onium salts, but to cleavage of the M–E bonds forming π-C5H5(CO)3MX (X ? I, Cl) and CH3ER2 and R2ECCl2F, respectively. The reactivity depends on ER2 and M: P(CF3)2 > P(CN)2 > As(CF3)2; Cr > Mo > W. Due to the low donor ability of the complexes 1a–c, 2a–c and 3a–c binuclear compounds π-C5H5(CO)3MER2W(CO)5 (E ? As, R ? CF3: 11a–c ; E ? P, R ? CN: 12a–c ; ER2?P(CN)Ph: 13a, b ) are obtained only with the highly reactive W(CO)5THF. In case of the (CF3)2P bridged derivatives spontaneous CO-elimination leads to the threemembered ring systems ( 10a–c ). 相似文献