Thermal behaviour of three silanethiolate zinc complexes i.e., bis(tri-tert-butoxysilanethiolato)bis(pyridine)zinc(II), bis(tri-tertbutoxysilanethiolato)bis(N-methylimidazole) zinc(II) and bis(tri-tert-butoxysilanethiolato) (2-methylpyridine) zinc(II) was studied. In order to determine the steps involved in thermal decay, decomposition intermediates were identified by means of IR spectroscopy and solid residues were analysed. Enthalpies of undergoing processes were estimated on the basis of DTA curves. The results of the study were applied to the synthesis of a new complex -bis(tri-tert-butoxysilanethiolato)(pyridine) zinc(II). NMR and IR spectra of this complex were measured and crystal and molecular structures were determined. (c) 2004 Elsevier B.V. All rights reserved.