The alkylcobalt halide [{(2-C5H4N)Me2Si (Me3Si)(2)CCoCl](2) (2) and the lithium silanolatocobaltates Li(THF)(2)(mu-Br)(2)Co(mu-OSiMe3)(2)Co(mu-Br)(2)Li(THF)(2) (4) and [LiBr{Li(THF)}(2) {CoBr(OSiMe3)(3)}](2) (5) form centrosymmetrical halogen-bridged dimers in the crystalline state. Compound 4 shows bromide bridges between lithium and cobalt, and silanolato bridges between the cobalt atoms. Below 200 K there are significant antiferromagnetic interactions between the cobalt centres. Compound 5 crystallises in a novel structure in which two cubane-like fragments containing silanolato bridges are linked together through a Li2Br2 ring. (C) 2004 Elsevier B.V. All rights reserved.

The lithium derivative Li(THF)C(SiMe3)(2)(SiMe2C5H4N-2) (1) reacted with AlCl3 or Me2AlCl to give, respectively, the monomeric compounds AlCl2C(SiMe3)(2)(SiMe2C5H4N-2) (2a) and AlMe2C(SiMe3)(2)(SiMe2C5H4N-2) (2b). The product from reaction with commercially available GaBr3 was the analytically pure monomeric heterocycle GaBr(OH)C(SiMe3)(2)(SiMe2C5H4N-2) (3), indicating that the starting halide had been partially hydrolysed before use. The reaction between I and commercially available InCl3 gave a homogenous white solid [InCl(mu-X)C(SiMe3)(2)(SiMe2C5H4N-2)](2) (4) with X = Cl (59%) or OH (41%). The X-ray crystal structures of 2a. 3, and 4 have been determined. (C) 2004 Elsevier B.V. All rights reserved.

The oxygen-bridged, silicon-substituted alkane {(Me3Si)(2)CH(SiMe2)}(2)O (1) may be prepared by the reaction of {(Me3Si)(2)CH}Li with ClSiMe2OSiMe2Cl in refluxing THF. Similarly, the alkane {(Me3Si)(Me2MeOSi)CH(SiMe2CH2)}(2) (2) is readily accessible from the reaction between {(Me3Si)(Me2MeOSi)CH}Li and ClSiMe2CH2CH2SiMe2Cl under the same conditions. Compound 1 reacts with two equivalents of MeK to give the polymeric complex [[{(Me3Si)(2)C(SiMe2)}(2)O]K-2(OEt2)](infinity)[5(OEt2)] after recrystallisation. Treatment of 2 with two equivalents of either MeLi or MeK gives the corresponding complexes [{(Me3Si)(Me2MeOSi)C(SiMe2CH2)}(2)Li][Li(DME)(3)][7(DME)(3)] and [{(Me3Si)(Me2MeOSi)C(SiMe2CH2)}(2)K-2](n) (8), respectively, after recrystallisation. Treatment of the alkane (Me3Si)(2)(Me2MeOSi)CH with one equivalent of MeK gives the polymeric complex [{(Me3Si)(2)(Me2MeOSi)C}K](infinity) (3). These compounds have been identified by H-1 and C-13{H-1} NMR spectroscopy and elemental analyses and compounds 5(OEt2), 7(DME)3 and 3 have been further characterised by X-ray crystallography. Compound 7(DME)3 crystallises as a solvent-separated ion pair, whereas 5(OEt2) and 3 adopt polymeric structures in the solid state.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Metallation of (HMe2Si)(Me3Si)(2)CH (1) by LiMe gave the organolithium compound Li(THF)(2)C(SiMe3)(2)(SiMe2H) (2a), which exists in toluene solution as a mixture of covalent species and ion pairs [Li(THF)(4)][Li{C(SiMe3)(2)(SiMe2H)}(2)] (2b). Treatment of a mixture of 1 and LiMe with KOBu1 gave KC(SiMe3)(2)(SiMe2H) (3). This reacted with AlMe2Cl in hexane/THF to give Al(THF)Me-2{C(SiMe3)(2)(SiMe2H)} (4). Treatment of (HMe2Si)(PhMe2Si)(2)CH (5) with LiMe in Et2O/THF gave the THF adduct [Li(THF)(2)C(SiMe2Ph)(2)(SiMe2H)] (6); in the presence of KOBut the solvent-free [K][C(SiMe2Ph)(2)(SiMe2H)] (7) was obtained. Crystal structure determinations showed that 6 crystallizes in a molecular lattice and 7 in an ionic lattice in which the coordination sphere of the potassium comprises phenyl groups and hydrogen atoms attached to silicon, as well as the central carbon of the bulky carbanion. Compound 7 reacted with an excess of AlMe2Cl to give [AlClMe{C(SiMe2Ph)(2)(SiMeH)}](2) (8) and AlMe3. A small amount of the methoxo derivative [Al(OMe)Me{C(SiMe2Ph)(2)(SiMe2H)}](2) (9) was obtained as a byproduct, presumably after the accidental admission of traces of air. X-ray structural determinations showed that 8 forms halogen-bridged dimers, with the bulky ligands in the anti-configuration, and 9 forms methoxo-bridged species in which the bulky ligands are syn. (C) 2004 Elsevier B.V. All rights reserved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The lithium reagent Li(THF)(2) {C(SiMe3)(2)(SiMe2NMe2)} (3) reacts with a molar equivalent of anhydrous zinc bromide to give the dimeric compound [Zn(mu-Br){C(SiMe3)(2)(SiMe2NMe2)}](2) (2a), in which zinc is four-coordinate. The product from a similar reaction with Li{C(SiMe3)(2)(SiMe2NPhMe)} is the lithium zincate [Li(THF)(2)(mu-Br)(2)Zn {C(SiMe3)(2)(SiMe2NPhMe)}] (4), in which the zinc is only three-coordinate. The crystal structures of 2a and 4 have been determined. (C) 2004 Elsevier B.V. All rights reserved.

By reaction of Me3SiSBu with anhydrous tin(II) chloride bis(butylthio)tin was obtained that exemplified a coordination polymer [Sn(SBu)2] n , whose elementary unit contained according to X-ray diffraction study three independent four-membered rings Sn2S2 of unusual geometry. It was demonstrated that polymeric thiolates [E(SBu)2] n (E = Ge, Sn) readily reacted with TsiLi (Tsi = C(SiMe3)3) in a mixed solvent ether THF affording in a good yield ate-complexes [(Me3Si)3CE(μ-SBu)2Li(THF)2]. Both complexes contain a four-membered ring in a butterfly conformation where the lithium atom is symmetrically bonded to both sulfur atoms, and the coordination polyhedra of Ge and Sn atoms may be regarded as distorted tetrahedra AB3X, where one of coordination places is occupied by unshared electron pair. The structure of the ate-complexes observed in a crystal is conserved also in solution of nonpolar solvents.

The first structurally characterized dialkylaluminate [{Li(THF)}(AltBu{C(SiMe3)(3)}H-2)](2) (3) is dimeric in the solid state with [Li(THF)](+) and [AltBu{C(SiMe3)(3)}H-2](-) fragments linked by (LiH)-H-...-Al bridges.

Care is necessary when relating physical data obtained at one temperature on compounds showing significant intermolecular interactions to X-ray data obtained at other temperatures. This is revealed by the determination of the structure of tri(cyclohexyl)tin chloride at nine different temperatures between 108 and 298 K. In the crystal, the molecules pack in chains parallel to the c axis with the Sn and Cl atoms close to the plane, with y = 0.25. At low temperature, successive molecules in the chain are related by the glide plane in space group P2(1)/c, and there is significant intermolecular interaction. As the temperature is raised, the Cy(3)SnCl.Sn interactions weaken and the intramolecular Sn-Cl bonds strengthen. At about 248 K, there is an order-disorder transition to space group P2(1)/m with the c axis halved, and at room temperature the structure is best described as comprising discrete molecules, as previously reported. Thus, some of the molecular dimensions, in particular the Sn-Cl bond lengths, are not constant but are functions of temperature.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The organolithium compound Li(THF)2{C(SiMe3)2(SiMe2NMe2)} reacted with one equivalent of MnCl2 to give [Mn(μ-Cl){C(SiMe3)2(SiMe2NMe2)}]2 (4) and with 0.5 equivalent of MnCl2 to give Mn{C(SiMe3)2(SiMe2NMe2)}2 together with a small amount of the MnIII compound [Mn(μ-O){C(SiMe3)2(SiMe2NMe2)}]2 (6) formed by adventitious admission of air. With CoBr2, the compound [Co(μ-Br){C(SiMe3)2(SiMe2NMe2)}]2 (7) was obtained. The reaction between the lithium compound Li(THF)2{C(SiMe3)2(SiMe2OMe)} and MnCl2 in THF gave [Mn(THF)(μ-Cl){C(SiMe3)2(SiMe2OMe)}]2 (5). The crystal structures of compounds 4, 5, 6 and 7 were determined. Compounds 4 and 5 are the first manganese analogues of Grignard reagents containing MnC σ-bonds to be characterised in the solid state.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The compound Li(thf)C(SiMe3)2(SiMe2C5H4N-2) (1) reacts with CuI or AuCl·SMe2 to give the dimeric compounds [MC(SiMe3)2(SiMe2C5H4N-2)]2 (M = Cu or Au), in which the bidentate ligand bridges two metal centres. Reactions of 1 with Group 12 halides of the form MX2 give the compounds MX{C(SiMe3)2(SiMe2C5H4N-2)} (M = Zn, X = Br; M = Cd, X = Cl; M = Hg, X = Cl). In the solid state, the zinc and cadmium compounds are halogen-bridged dimers, but the mercury compound is monomeric, with only weak interaction between mercury and nitrogen.

The ‘lower order’ lithium cyanocuprates [Li(thf)2NCCu{C(SiMe3)3}]2 (1d), [Li(thf)2NCCu{C(SiMe3)2(SiMe2NMe2)}]2 (1e) and [Li(thf)NCCu{C(SiMe3)(SiMe2OMe)2}]2 (3) have been obtained from the reactions between copper(I) cyanide and the corresponding organolithium compounds. The compounds 1d and 1e have molecular structures containing four-membered Li2N2 rings but in 3 the lithium is coordinated by the methoxy groups of the ligand and almost linear LiNCCuC sequences are incorporated into fourteen-membered rings. Attempts to make ‘higher order’ cyanocuprates containing tri(organosilyl)methyl groups were unsuccessful and no reactions were observed when the cyanocuprate 1d was treated with alkyl halides or enones.

Reaction of the highly crowded organotin iodide CH2Me2Si(Me3Si)(2)CSnMeIC(SiMe3)(2)SiMe2CH2 with AgBF4 gives the fluoride CH2Me2Si(Me3Si)(2)CSnMeFC(SiMe3)(2)SiMe2CH2. Reaction with AgOSO2C6H4Me followed by workup in moist air gives the hydroxide CH2Me2Si(Me3Si)(2)CSnMe(OH)C(SiMe3)(2)SiMe2CH2, 2f. With AgOSO2CF3 the product is the organosilicon trifluoromethanesulfonate CH2Me2Si(Me3Si)(2)CSnMe2C(SiMe3)(SiMe2OSO2CF3)SiMe2CH2, 5, formed apparently by an unprecedented 1,3-migration of a methyl group from silicon to tin within a cation. Compound 5 and Ph3SiOSO2CF3 are the first silicon trifluoromethanesulfonates to be characterized by X-ray structure determinations. In both the Si-O bonds are long, ca. 1.75Angstrom, consistent with the ready nucleophilic displacement of [OSO2CF3](-) from silicon centers. The crystal structures of the fluoride CH2Me2Si(Me3Si)(2)CSn(CH2Ph)FC(SiMe3)(2)SiMe2CH2 and the hydroxide 2f have also been determined.

The ate complexes [M{C(SiMe3)(3)}(mu-SBu)(2)Li(THF)(2)], M = Ge or Sn, have been made from M(SBu)(2) and LiC(SiMe3)(3) in tetrahydrofuran and their crystal structures determined. The LiS2M rings are. folded at the S...S axis, the ring in the tin compound more so than that in the germanium derivative. The latter has a conformation very like the ring in [(Me3Si)(3)CAl(SMe)(mu-SMe)(2)Li(THF)(2)]. NMR measurements show that the LiS2M rings are preserved in toluene solution, but the Li-S bonds in the tin compound are transiently broken in THF.

The reaction of [Li(thf)(2)AlH3{C(SiMe3)(3)}](2) (1) with four equivalents of ArOH (Ar = C6H3Pr2i-2,6) yielded [Li(thf)-(mu-OAr)(2)AlH{C(SiMe3)(3)}] (2) (thf = tetrahydrofuran), which has a structure containing a four-membered LiO2Al ring both in the crystal and in toluene solution. The corresponding reaction with ArOH (Ar = C6H3Bu2t-2,6) gave a mixture that could not be separated by fractional crystallisation. The reaction of 1 with Ph3SiOH gave [Al(OSiPh3)(2)-{C(SiMe3)(3)}(thf)] (3), which was shown by an X-ray structure determination to be monomeric.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.