Although neglected for many years, p-block metals such as tin(IV), germanium(IV), bismuth(III) and metalloids like antimony(III) have a rich coordination chemistry, and the complexes are potential single source precursors to electronic materials.
Our studies have resulted in the characterisation by X-ray crystallography and multinuclear NMR spectroscopy (77Se, 125Te, 119Sn) of tin(IV) complexes of dithio-, diseleno- and ditelluroethers and thiamacrocycles. Bismuth(III) and antimony(III) halides have produced a very rich range of structures with the same ligands including examples were MX3 or M2X6 units are linked by bridging group 16 ligands into infinite 3-D polymers, through to ladders and helices where pyramidal MX3 groups are linked by polydentates into supramolecular arrays. Complexes of Bi(III), Sb(III) and As(III) with phosphine and arsine ligands have also been prepared including such novel species as [As2X6(o-C6H4(AsMe2)2)2] where the arsenic halide functions formally as the Lewis acid and the arsine as the Lewis base.Complexes of main group fluorides have been little investigated, but we have recently characterised a series of adducts of SnF4 and GeF4 with both hard N- and O- donors and with soft phosphine and thioether ligands, with detailed characterisations based upon multinuclear NMR spectroscopy and X-ray crystallography. Similar studies with silicon(IV) and germanium(II) halides are underway. Gallium(III) and indium(III) halide complexes with phosphine, arsine and stibine ligands are being explored with the aims of understanding how ligand architecture and denticity control the stoichiometry and reactivity of the complexes formed. This work provides an essential [GeF4{EtS(CH2)2SEt}]background to the use of related complexes as single source precursors for electronic materials such as GaP or GaAs.