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Describes the structure of the homoleptic and monomeric metal alkyls bis{[diphenyl(piperidinomethyl)silyl]-methyl}cadmium and bis{[diphenyl(piperidinomethyl)silyl]-methyl}magnesium. Crystallographically imposed carbon(II) symmetry of the molecules; Location of metal centers on special positions.

In the title compound, C23H31NO2S, the geometry of the triiso-propyl-phenyl group is slightly distorted, with elongated C-C bonds at the ipso-C atom, and an S atom which deviates from the benzene ring plane by 0.228 (2) Å. This distortion is caused by the bulky substituents and, in comparison, an unbent geometry is observed in N-toluene-sulfonyl-aziridine [Zhu et al. (2006 ▶). Acta Cryst. E62, o1507-o1508]. π-π inter-actions between adjacent benzene rings [centroid-centroid distance = 3.7928 (11) Å] and are observed.

The title compound, [FePt(C(9)H(9)NO(2)S)(C(18)H(15)P)(C(25)H(22)P(2))(CO)(3)], represents a rare example of an isonitrile-bridged heterobimetallic complex (here Pt and Fe) and is an inter-esting precursor for the preparation of heterodinuclear μ-amino-carbyne complexes, since the basic imine-type N atom of the μ(2)-C=N-R ligand readily undergoes addition with various electrophiles to afford iminium-like salts. In the crystal, the almost symmetrically bridging μ(2)-C=N-R ligand (neglecting the different atomic radii of Fe and Pt) is strongly bent towards the Fe(CO)(3) fragment, with a C=N-R angle of only 121.1 (4)°.

In the title compound, C(21)H(18)Si, the coordination geometry around the Si atom is a slightly distorted tetra-hedron with C-Si-C angles in the range 106.05 (11) to 110.58 (10) ° and Si-C bond lengths in the range 1.855 (2) to 1.883 (3) Å. The alkyne C-C bond length is 1.167 (4) Å. The dihedral angles between the three phenyl rings are 63.89 (7), 86.38 (7) and 70.51 (8)°. In the crystal, mol-ecules inter-act only by van der Waals forces.

The title compound, C(19)H(24)ClNO(5), was synthesized and subsequently employed in an Evans alkyl-ation. The purpose was to prove the absolute configuration in the projected synthesis of the side chain of (-)-Lytophilippine A. The oxazolidinone and the isopropylidene acetal rings have twisted conformations. The oxazolidinone and side-chain carbonyl groups are orientated in an anti-periplanar arrangement to minimize van der Waals repulsions. Furthermore, the Cl atom and the acetonide-protected secondary alcohol are also in an anti-periplanar arrangement with a torsion angle of 173.64 (14)°. The absolute configuration was determined and agrees with the configuration of the used chiral auxiliary.

The title compound, C(12)H(18)N(4)O(2)SSi, was synthesized to be employed in a Julia-Kocieński olefination. In the mol-ecule, the dihedral angle between the phenyl ring and the tetra-zole ring is 41.50 (5)°. The significantly longer Si-C(methyl-ene) bond [1.8786 (13) Å] and the shortened adjacent C-C bond [1.5172 (18) Å], as well as the significant deviation of the corresponding Si-C-C angle [114.16 (9)°] from the ideal tetra-hedral angle, can be attributed to the β-effect of silicon. In the crystal, mol-ecules are held together by van der Waals inter-actions.

The title compound, poly[(μ(2)-2H,5H-1,3-dithiolo[4,5-d][1,3]di-thiole-2,5-dithione)hexa-μ(2)-iodido-diiodidotetra-mercury(II)], [Hg(4)I(8)(C(4)S(6))](n), represents the first example of a coordination polymer assembled by the α,α-C(4)S(6) dithione ligand. The Hg(II) ions are four-coordinated in a distorted tetra-hedral geometry, the coordination demand being satisfied either by four bridging iodide ligands or by three iodide ligands (one terminal and two bridging) and a thio-carbonyl S atom. Due to the bridging nature of the dithione ligand, the coordination polymer has a two-dimensional structure, built up of undulated layers parallel to (001). There is an inversion center at the mid-point of the central C=C double bond.

The title compound, C(6)H(4)Br(2)S, represents a versatile building block for the preparation of π-conjugated redox-active thienyl oligomers and metal-mediated cross-coupling reactions. This is due to the presence of an electrochemically active thienyl heterocycle and a reactive dibromo-vinyl substituent, which easily undergoes dehydro-bromination in the presence of n-butyl-lithium to afford 2-ethynyl-thio-phene. In the molecule, the alkenyl unit and the thio-phene ring are almost coplanar with an angle of 3.5 (2)° between the normals of the best planes of the thio-phene ring and the vinyl moiety.

In the title compound, [Cu(C(15)H(26)N(2)O(2))(C(3)H(7)NO)(2)][SbF(6)](2), which is a potential catalyst in the catalytic asymmetric Gosteli-Claisen rearrangement, the central Cu(II) atom is in a nearly square-planar cis-N(2)O(2) environment in the cation arising from its coordination by an N,N-bidentate 2,2-bis-[(4S)-4-isopropyl-4,5-dihydro-1,3-oxazol-2-yl]propane ligand and two O-bonded N,N-dimethyl-formamide mol-ecules. Two SbF(6) (-) anions are positioned on opposite sides of the plane through the CuN(2)O(2) unit, generating an axially distorted CuN(2)O(2)F(2) octa-hedral geometry for the metal ion.

The title compound, C(22)H(24)OSi or Ph(3)SiO(t)Bu, shows a distorted tetra-hedral coordination sphere around the Si atom. The C-O-Si angle is 135.97 (12)° and the O-Si distance is 1.6244 (13) Å. The mol-ecules are held together by weak inter-actions only. An H⋯H distance of 2.2924 (7) Å is found between aryl H atoms and is the shortest inter-molecular distance in the structure. With regard to the broad applicability of R(3)SiO structural motifs in all fields of chemistry, the mol-ecule demonstrates a common model system for silicon centers surrounded by sterically demanding substituents.

The title compound, [ZnBr(2)(C(12)H(28)N(2)Si)], is an example of a neutral coordination compound of a bidentate ligand to a metal centre with the Zn atom being coordinated by two Br and two N atoms, yielding a slightly distorted tetra-hedral coordination environment.

The title compound, C(16)H(34)N(2), is a chiral diamine with fixed R configuration at both stereogenic carbon centres of the cyclo-hexane backbone. Due to their different substituents, the two N atoms also become stereogenic. In the crystal structure, the configuration at one of the two nitro-gen centres is fixed, with the free electron pair pointing inward and the isobutyl group in a trans position towards the cyclo-hexane backbone resulting in an R configuration. The isobutyl group at the second N atom, however, is disordered with 75% S configuration and 25% R configuration. In both cases, the isobutyl group is arranged in a trans position towards the cyclo-hexane backbone.

The title compound, [Fe(C(5)H(5))(C(7)H(5)Cl(2))], represents a versatile building block for the preparation of π-conjugated redox-active compounds or polymetallic organometallic systems due to the presence of the electrochemically active ferrocenyl unit. It is therefore a potential starting material for the preperation of the corresponding alkyne. In the crystal, the alkenyl unit and the cyclo-penta-dienide ring are almost parallel, with an angle between the best planes of only 10.6 (4)°.

In the title compound, C(20)H(16)Br(4), both vinylic substituents were introduced by a Corey-Fuchs reaction using 4,12-diform-yl[2.2]paracyclo-phane as starting material. The title compound may be used as a valuable precursor for the synthesis of diethyn-yl[2.2]paracyclo-phane. The title mol-ecule is centrosymmetric with a crystallographic center of inversion between the centers of the two phenyl rings. A strong tilting is observed with an inter-planar angle between the best aromatic plane and the vinyl plane of 49.4 (5)°. No significant inter-molecular inter-actions are found in the crystal.

The title compound, C(19)H(27)N(2)O(+)·Br(-), is the hydro-bromide of the trapping product of lithia-ted N,N,N',N'-tetramethylethylenediamine (TMEDA) with benzophenone. Thereby, the N atom of the NMe(2) group is selectively protonated and the respective trapping product represents a potential tridentate ligand with one O and two N donor atoms. The H atoms at N (H2N) and O (H1O) are involved in hydrogen bonds with the Br(-). The mol-ecular structure shows all donor atoms to be arranged on one side of the mol-ecule, thus indicating a potential threefold coordination of a Lewis acid.

The title compound, C(26)H(34)NSi(2) (+)·Cl(-), shows chirality at silicon. Because of its highly selective synthesis with an e.r. of >99:1 by means of a racemic resolution with mandelic acid, the free disilane is of great importance to the chemistry of highly enanti-omerically enriched lithio-silanes and their trapping products. N-H⋯Cl hydrogen bonding is present between the protonated nitro-gen atom of the piperidino group and the chloride counter-anion. The silicon-silicon distance as well as silicon-carbon and carbon-nitro-gen bond lengths are in the same ranges as in other quaternary, functionalized di- and tetra-silanes.

The molecule of the title compound, C(8)H(18)N(2), possesses C(2) symmetry. Owing to its stereochemistry, it is used in the synthesis of chiral ligands and metal complexes for asymmetric synthesis. The cyclo-hexane ring shows a chair conformation with the amino groups in equatorial positions. Contrary to the literature, the title compound is not a liquid, but a crystalline solid at room temperature (293 K). The absolute configuration is assigned from the synthesis.