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Using single crystal X-ray diffraction analysis and quantum chemical calculations, a model system for metalation reactions, the deprotonation of (tert-butylamino)(piperidinomethyl)dimethyl-silane (1) with Et(2)Zn, was established allowing for the isolation of a reactive intermediate, the adduct structure [1·Et(2)Zn] (2).

We herein present the synthesis and crystallographic characterisation of lithium silylamides displaying different coordination numbers and aggregation states according to the number of N- and O-donor functions in the starting material, (aminomethyl) substituted silazane ligands. The dimeric dimethyl-(N-lithio-tert-butylamino)-piperidinomethyl)-silane and dimethyl-(N-lithio-iso-propylamino)-piperidinomethyl)-silane, with three-coordinate lithium centres, were prepared by deprotonation of the corresponding silazane with (n)BuLi. Using the tridentate silazane (1R,2R)-N(1)-[{(tert-butylamino)-dimethylsilyl}methyl]-N(1),N(2),N(2)-trimethylcyclohexane-1,2-diamine a mixed "dimer" of lithium silylamide and lithium silanolate with four-coordinate lithium centres was obtained. Additionally, a monomeric lithium silylamide was synthesised using the tridentate [bis(methoxyethyl)aminomethyl] side arm.

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, [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.