首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
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   

2.
Preparation of Chelating Ligands of the Type Me2XSiMe2CH2X′Me2 (Me = CH3; X, X′ = N, P and/or As) Chelating Ligands of the general type Me2XSiMe2CH2X′Me2 (Me = CH3; X, X′ = N, P As) are obtained from ClSiMe2CH2Cl by the following reactions (see “Inhaltsübersicht”). The new compounds have been characterized by analytical and spectroscopic methods (IR, NMR, MS).  相似文献   

3.
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   

4.
Chelate Complexes of the Type M(CO)4(Me2XGeMe2CH2X′Me2) (M) = Cr, Mo, W; X, X′ = N, P, As; Me = CH3) The ligands (Me2)XGeMe2CH2X′Me2 (M) = Cr, Mo, W) react with M(CO)4norbor (norbor = Norbornadiene) (M = Cr, Mo, W) yielding the chelate complexes M(CO)4(Me)2XGeMe2CH2X′Me2). compounds of low thermal stability are formed with the ligands (Me2NGeMe2CH2X′Me2 because of the weak donor ability of the GeNMe2 group and with Me2AsGeMe2CH2NMe2 caused by strong steric ring tension. The new compounds are characterized by analytical and spectroscopic (n.m.r., i.r., m.s.) investigations.  相似文献   

5.
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   

6.
Alternative Ligands. XXXI. Nickelcarbonyl Complexes of Tripod Ligands of the Type XM′(OCH2PMe2)n(CH2CH2PR2)3–n (M′ = Si, Ge; n = 0–3) The coordinating properties of the tripod ligands RM′(OCH2PMe2)n(CH2CH2PMe2)3–n (M′ = Si, Ge) ( 1–7 ), MeSi(OCH2PMe2)2CH2CH2P(CF3)2 ( 8 ), MeSi(OCH2PMe2)2CH2CH2NMe2( 10 ) as well as of the tetradentate representative Si(OCH2PMe2)4 ( 9 ) have been investigated by the preparation of the novel nickel carbonyl complexes LNiCO ( 11–18 ), Si(OCH2PMe2)4[Ni(CO)2]2 ( 19 ) and (HOCH2PMe2)2Ni(CO)2 ( 20 ). They are obtained in moderate to good yields by the reaction of Ni(CO)4 with the corresponding ligands in toluene (20–111°C) (see Table 1). The new compounds have been characterized by analytical (C, H) and spectroscopic investigations (IR; 1H-, 13C-, 19F, 31P-NMR, MS). The ligand properties are discussed on the basis of spectroscopic data [in particular coordination shifts Δδ = δ(complex)—δ(ligand)] leading to the conclusion that the high electron density on Ni gives rise to a weak, but significant Ni→Si interaction. An important indication comes from the large low field shift ΔδF = 34.5 ppm for the SiF acceptor bridge in 17 . This result is supported by an X-ray diffraction study of 11 giving an NiSi distance of 3.941(2) Å. With the exception of O2…?P3 (Abb. 7) all other O…?P through-cage contacts are longer than the NiSi distance. An additional release from the high charge density on Ni is obtained via π-backbonding to the neighbouring groups OCPMe2, CCPMe2 and CO.  相似文献   

7.
Novel Syntheses of Me2SbX (X = Cl, I) and Crystal Structures of Me2SbI and [(Me3Si)2CH]2SbCl The crystal structures of Me2SbI (Me = CH3) and [(Me3Si)2CH]2SbCl have been determined by X‐ray methods. Both molecules are pyramidal. The Me2SbI molecules are associated to chains through short intermolecular Sb…I distances (366,7(1) pm) with linear I–Sb…I units (171,87(4)°) and bent Sb–I…Sb bridges (116,83(3)°).  相似文献   

8.
Alternative Ligands. XXX Novel Tripod Ligands XM' (OCH2PMe2)n(CH2CH2PMe2)3?n (M' = Si, Ge; n = 0–3) for Cage Structures Attempts to prepare new tripod ligands XSi(OCH2PMe2)3 [X = CF3 ( 15 ), C6F5 ( 16 ), NMe2 ( 17 ), Cl ( 18 ), F ( 19 ), H ( 20 ), OEt ( 21 ), OMe ( 22 )] prove to be unsuccessful in spite of using different pathways, because the groups X undergo following reactions giving insoluble solids (polyadducts) or form inseparable mixtures, e. g. (RO)nSi(OCH2PMe2)4?n (R = Me, Et). In many cases Si(OCH2PMe2)4 ( 13 ) can be isolated from the reaction mixture. The syntheses of the ligands XSi(CH2CH2PMe2)3 [X = NMe2 ( 6 ), Cl ( 7 ), F ( 8 ), OMe ( 9 ), Vi ( 12 )], Si(OCH2PMe2)4 ( 13 ) und Me3GeOCH2PMe2 ( 14 ) are successful. The compounds MeSi(OCH2PMe2)2CH2CH2NMe2 ( 10 ) and MeSi(OCH2PMe2)2CH2CH2P(CF3)2 ( 11 ) with different donor groups are obtained in good yields. The preparative program includes the synthesis of the known representatives MeSi(OCH2PMe3)3 ( 1 ), MeSi(OCH2PMe2)2CH2CH2PMe2 ( 2 ), MeSi(OCH2PMe2)(CH2CH2PMe2)2 ( 3 ), MeSi(CH2CH2PMe2)3 ( 4 ) and MeGe(OCH2PMe2)3 ( 5 ). Important preparative steps are the substitution of M'Cl (M' = Si, Ge) by Me2PCH2O groups and the photochemically induced or base catalyzed addition of HNMe2, HPMe2 or HP(CF3)2 to SiVi functions. The novel compounds are characterized by analytical and spectroscopic (IR, NMR, MS) investigations.  相似文献   

9.
Alternative Ligands. XXV. New Chelating Ligands of the Type Me2ESiMe2(CH2)2E′Me2 (E=P, As; E′=N, P, As) Chelating ligands of the type Me2EsiMe2(CH2)2E′ Me2, have been prepared by the following routes: Starting from Me2Si(Vi)Cl, the compounds with E=N and E′ =N ( 1 ), P ( 2 ), As ( 3 ) are obtained in yields of 65 to 78% by aminolysis to yield Me2NSiMe2Vi, followed by the LiE′ Me2 catalyzed addition of He′Me2 to the vinyl group. The intermediates ClSiMe2(CH2)E′Me2 [E′=N ( 4 ), P ( 5 ), As ( 6 )] are produced by the reactions of 1 to 3 with PhPCl2. 5 and 6 can be prepared in a purer form by the photochemical addition of HPMe2 and HAsMe2, respectively, to the vinyl group of Me2Si(Vo)Cl. 4 to 6 react with LiEMe2, in situ prepared from n-BuLi and HEMe2, to yield the ligands Me2ESiMe2(CH2)2E′Me2 ( 7–12 ) (E=P, As; E′=N, P, As). The new compounds have been characterized by analytical and spectroscopic investigations (NMR, MS).  相似文献   

10.
Alternative Ligands. XXI. Novel Donor/Acceptor Ligands Me2PCH2CH2SiFnMe3-n, Me2PCH2CH2SiR(C6H4F)2, and (2-Me2PC6H4)SiXMe2 Donor/acceptor ligands of the type Me2PCH2CH2SiX3 [X = Cl ( 1 ), F ( 2 ), Me ( 3 ), OMe ( 4 )], (Me2PCH2CH2)2SiX2 [X = Cl ( 6 ), F ( 7 )], Me2PCH2CH2SiX(C6H4F)2 [X = F ( 5 ), Me ( 8 )], and Me2PCH2CH2SiXnMe3-n[n = 1; X = Cl ( 10 ), F ( 11 ); n = 2; X = F ( 9 )] are prepared in yields between 42 and 95% by photochemical addition of Me2PH to the corresponding vinylsilane precursors. In case of the halogen containing representatives formation of solid polyadducts, due to Lewis acid/base interaction between P-donor and Si-acceptor function, reduces the yields. Ligands of the type (2-Me2PC6H4)SiXMe2 [X = NMe2 ( 12 ), Cl ( 13 ), F ( 14 )] are obtained by two different routes (Abb. 3), using 2-chlorobromobenzene as the starting material. New compounds have been characterized by analytical (C, H) and spectroscopic (NMR, MS) investigations. In order to elucidate the associative properties compounds 2 and 9 were used for the following experiments:
  • – Study of the influence of dissolution on the proton and fluorine resonances of 2 and 9 ,
  • – investigation of the adduct equilibrium (–H2CF3Si←PMe2CH2–)n + nBF3 → n[F3B←PMe2CH2CH2SiF3],
  • – cleavage of the polyadduct of 2 using [NH4]F and [Me4N]F, respectively, for the formation of hexacoordinate complex anions [Me2PCH2CH2SiF5]2?.
The results obtained confirm the assumption that oligo- and polymerisation are due to P→Si interaction.  相似文献   

11.
Single crystal X‐ray diffraction analyses of LSn(OCH2CH2)2NR [ 1 , R = Me, L = lone pair; 2 , R = Me, L = W(CO)5; 3 , R = t‐Bu, L = W(CO)5] reveal these compounds to be dimeric and cis‐configurated. The dimerization is realized by intramolecular O→Sn interactions to give four‐membered Sn2O2‐rings. In addition, there are intramolecular N→Sn interactions ranging in between 2.356(5) ( 2 ) and 2.549(4) Å ( 3 ).  相似文献   

12.
13.
Formation of Organosilicon Compounds. 97. About the Influence of the Si-Substituents (Me, Cl) upon the Formation and the Reactions of Ylides 1,3-disilapropanes with different grade of chlorination or methylation at the silicon atoms and containing a CCl2 group cleave the Si? P bond of Me3SiPMe2. By subsequent rearrangement ylides with ? PMe2Cl group are formed. The reactivity of the CCl2 group depends on the grade of Si-chlorination resp. Si-methylation. Si-methylation decreases the reactivity of the CCl2 group. The reaction of 1,3-disilapropanes and Me3SiPMe2 (molar ratio 1:1) runs in a sequence shown in “Inhaltsübersicht”. Ylid C is able either to react with the initial compound A forming B, or in competition decomposes forming D. Reacting Si-perchlorinated carbosilanes, the decomposition forming D is not to be observed. In Si-methylated ylides like (Me3Si)2C?PMe2? PMe2 and (Me3Si)2C?PMe2? P(Me)SiMe3 the ylid carbon atom is able to abstract a proton of the P? CH3 group resp. P? H groups of the trivalent phosphorus forming (Me3Si)2C(H)PMe2. The rearrangement is proved by deuterated derivatives. The different behaviour is due to the increased basicity of the ylid-C atom in Si-methylated phosphorus ylides. Quite the same behaviour show the phosphorus ylides of 1,3,5-trisilacyclohexane.  相似文献   

14.
Vibrational Spectra and Force Constants of W(OCH3)6, Mo(OCH3)6, and [Sb(CH3)4][Sb(OCH3)6] The infrared and Raman spectra of the monomeric hexamethoxides of Tungsten and Molybdenum and of the ionic compound [Me4Sb]+[Sb(OMe)6]? (prepared from [Sb(OMe)5]2 and Me4SbOMe; Me = CH3) are recorded and interpreted on the basis of C3i symmetry. The force fields of W(OMe)6 and [Sb(OMe)6]? are calculated using the same basis set of force constants. Both W? O- and Sb? O- stretching force constants are identical (2.56 N/cm), however the other parts of the valence force field are markedly different.  相似文献   

15.
Alternative Ligands. XXXII [1]. Novel Tetraphosphane Nickel Complexes with Tripod-Ligands of the Type XM′(OCH2PMe2)n(CH2CH2PR2)3 – n (M′ = Si, Ge; n = 0 – 3) Tripod Ligands of the type XM′(OCH2PMe2)n(CH2CH2PMe23 – n (M′ = Si, Ge; n = 0 – 3) ( 1 – 6 , Table 1) have been used together with PPh3 or PMe3 for the preparation of novel tetraphosphane complexes of Nickel. The representatives LNiPPh3 ( 7 – 12 ) are obtained by reaction of Ni(COD)2 (COD = 1,5-cyclooctadiene) with the corresponding ligands and PPh3 in toluene in moderate yields. The synthesis of the derivatives LNiPMe3 ( 13 – 18 ) is partly ( 16 – 18 ) accomplished in analogy to the Ph3P-complexes; compounds 13 – 16 are obtained in higher yields by reaction of Ni(PMe3)4 with the respective ligand. As a rule, 13 – 18 cannot be separated from by-products. The trinuclear complex FSi(CH2CH2PMe2)3[Ni(PMe2CH2CH2)3SiF]3 ( 19 ) is formed together with 18 in the reaction of Ni(COD)2 with 6 and PMe3. The new compounds have been characterized (if possible) by analytical (C, H), but in general by spectroscopic investigations (IR; 1H-, 13C-, 19F-, 31P-NMR; MS). A weak, but significant Ni → Si interaction through the cage is indicated by the following results: (i) Large low-field shifts δδF of 35.2 ppm ( 12 ), 38.3 ppm ( 18 ) and 37.7 ppm ( 19 ); (ii) 6J(PF) coupling constants [or 3J(PNiSiF) through the cage] of 6.0 Hz ( 12 ) and 7.6 Hz ( 18 ) together with a low-field shift δδSi of 12.8 ppm ( 12 ); (iii) NiSi distances of 3.95 Å in 7 and 3.92 Å in 12 , accompanied by a compression of the cage along the Ni ··· Si axis. An additional release from the high charge density on Ni results from π-backbonding to the phosphane ligands.  相似文献   

16.
Germatranes bearing a ferrocenylalkoxyl moiety have been obtained by the reaction of HOGe(OCH2CH2)3N with various ferrocenyl alcohols. A convenient new synthesis method of FcCH2OGe(OCH2CH2)3N was reported. FcCH2OGe(OCH2CH2)3N was prepared in 93% yield when FcCH2OH reacted with HOGe(OCH2CH2)3N in chloroform at room temperature in the presence of molecular sieves (3 Å) as a dehydrating agent. All compounds were characterized by elemental analysis, 1H NMR and IR spectroscopy. The molecular structures of FcCH2OGe(OCH2CH2)3N and FcCH(CH3)OGe(OCH2CH2)3N have been determined by X‐ray diffraction. The antitumor activities of FcCH2OGe(OCH2CH2)3N and p‐FcC6H4CH2OGe(OCH2CH2)3N were determined. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

17.
Studies on Selenium Compounds. LXV. On Compounds of the Type (CH3O)3 SeX with X ? F, Cl, Br, NO3, AlCl4 Reaction of Se(OCH3)4 with SeX4(X ? Cl, Br)(mole ratio 3:1) yields (CH3O)3SeX. The compounds (CH3O)3SeX (X ? F, NO3) are formed by reaction of (CH3O)3SeCl with the silver salts AgF and AgNo3, respectively. (CH3O)3SeAlcl4 is prepared by reaction of (CH3O)3SeCl with AlCl3. Some properties of the synthezised compounds and the ir spectra are given. From their data deduction concerning the nature of the chemical bonds in the compounds (CH3O)3SeX are possible.  相似文献   

18.
Reaction of tetrafluorosilane with tris(2-hydroxyethyl)-and tris(2-trimethylsiloxyethyl)amine results in formation of 1-fluorosilatrane and fluorosilatrane in 75 and 53% yield, respectively. Reaction of tetrafluorosilane with bis(2-trimethylsiloxyethyl)amine and its N-methyl derivative leads to the hitherto unknown 1,1-difluoroquasisilatranes (N → Si) F2Si(OCH2CH2)2NR (R = H, Me) containing donor-acceptor bond N → Si and pentacoordinate silicon atom. The structure of the synthesized compounds was proved by 1H, 13C, 15N, 19F, 29Si NMR and IR spectroscopy.  相似文献   

19.
Alternative Ligands. XXXVI. Novel Rhodium(I) Complexes with Donor/Acceptor Chelating Ligands In order to generate metal base/Lewis‐acid interactions in rhodium(I) phosphane complexes the binuclear complex [Rh(CO)2Cl]2 was reacted in benzene with dipod ligands of the type R2M′(OCH2PMe2)x(CH2CH2PMe2)2–x (R = F, Me; M′ = Si, Ge; x = 0–2) using the Ziegler dilution principle with the aim to produce mononuclear compounds in which with formation of five‐membered chelate rings in principle Rh → M′ contacts are possible. The reactions of ligands 1 – 7 (Table 1) with [Rh(CO)2Cl]2 proceed under CO elimination and, in spite of large turnovers, lead to a variety of products 8 – 14 (Table 1), in case of 11 , 13 and 14 accompanied by degradation of the corresponding ligands. Intact ligands are present in the 16‐membered rings of the binuclear complexes 8 – 10 and 12 , for which, due to the molecular structure, Rh → M′ interactions can be excluded. In the reaction of Me2Si(OCH2PMe2)2 ( 4 ) with [Rh(CO)2Cl]2 the unusual binuclear system 11 with a central Rh2O2 four‐membered ring and two RhO(SiMe2OCH2PMe2) six‐membered rings is formed. Small amounts of the mononuclear compounds Rh(CO)Cl(Me2PCH2OH)2 ( 13 ) and Rh(CO)Cl3(Me2PCH2OH)2 ( 14 ), respectively, are obtained in crystalline form from the reaction mixtures of [Rh(CO)2Cl]2 with Me2Ge(OCH2PMe2)(CH2CH2PMe2) ( 6 ) or Me2Ge(OCH2PMe2)2 ( 7 ). The new complexes were characterized by analytic (C, H), spectroscopic (NMR, IR, MS) and, except for 12 , by single crystal structural analyses.  相似文献   

20.
Formation of Organosilicon Compounds. 110. Reactions of (Cl3Si)2CCl2 and its Si-methylated Derivatives as well as of (Cl3Si)2CHCl, (Cl3Si)2C(Cl)Me and Me2CCl2 with Silicon (Cu cat.) The reactions of (Cl3Si)2CCl2 1 , its Si-methylated derivatives (Me3Si)2CCl2 8 , Me3Si? CCl2? SiMe2Cl 9 , (ClMe2Si)2CCl2 10 , Me3Si? CCl2? SiMeCl2 11 , Cl2MeSi? CCl2? SiCl3 12 as well as of (Cl3Si)2CHCl 38 , (Cl3Si)2CClMe 39 and of Me2CCl2 with Si (Cu cat.) in a fluid bed reactor ( 38 and 39 also in a stirred solid bedreactor) arc presented. While (Cl3Si)2CCl2 1 yields C(SiCl3)4 2 the 1,1,3,3-tetrachloro-2,2,4,4-tetrakis(trichlorsilyl)-1,3-disilacyclobutane Si6C2Cl16 3 and the related C-spiro linked disilacyclobutanes Si8C3Cl20 4 , Si10C4Cl24 5 , Si12C5Cl28 6 , Si14C6Cl32 7 this type of compounds is not obtained starting from the Si-methylated derivatives 8, 9, 10, 11 They Produce a number of variously Si-chlorinated and -methylated tetrasila- and trisilamethanes. However, Cl2MeSi? CCl2? SiCl3 12 forms besides of Si-chlorinated trisilamethanes also the disilacyclobutanes Si6C2Cl15Me 34 and cis- and trans Si6C2Cl14Me2 35 as well as the spiro-linked disilacyclobutanes Si8C3Cl19Me 36 , Si8C3Cl18Me2 37 . (Cl3Si)2CHCl 38 mainly yields HC(SiCl3)3 31 and also the disilacyclobutanes cis- and trans-(Cl3Si)HC(SiCl2)2CH(SiCl3) 41 and (Cl3Si)2C(SiCl2)2CH(SiCl3) 45 the 1,3,5-trisilacyclohexane [Cl3Si(H)C? SiCl2]3 44 as well as [(Cl3Si)2CH]2SiCl2, and (Cl3Si)2CClMe 39 mainly yields (Cl3Si)2C?CH2and (Cl3Si)2besides of HC(SiCl3)3, MeC(SiCl3)3and (Cl3Si)3C? SiCl2Me.,. Me2CCl2 59 mainly yields Me(Cl)C?CH2, Me2CHCl and HCl2Si? CMe2? SiCl3, besides of Me2C(SiCl3)2 and Me2C(SiCl2H)2 Compound 3 crystallizes triclinically in the space group P1 (Nr. 2) mit a = 900,3, b = 914,0, c = 855,3 pm, α = 116,45°, β = 101,44°, γ = 95,86° and one molecule per unit cell. Compound 4 crystallizes monoclinically in thc space group C2/c (no. 15) with a = 3158.3,b = I 103.7, c = 2037.4 pm, β = 1 16.62° and 8 molecules pcr unit cell. The disilacyclobutane ring of compound 3 is plane, showing a mean distance of d (Si-C) =19 1.8 pm and the usual deformations of endocyclic angles: αSi = 94,2°> 85,8° = αC.The spiro-linked disilacyclobutane rings of compound 4 are slightly folded by a mean angle of (19.0°). Their mean distances were found to be d (Si? C) = 190.4 pm relating to the central carbon atom and 192.0 pm to the outer ones, respectively. The deformations of endocyclic angles: αSi = 93,9°> 84,4° = αC are comparable to those of compound 3.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号