A series of five heteronuclear zinc tin chalcogenide complexes with the general formula [(tmeda)Zn(SnR2)(2)E-3] (1-R, E = S; R = Me, Ph, tBu; 2-R, E = Se; R = Ph, tBu) have been synthesized and characterized by X-ray crystal structure analysis. In all cases, the six-membered ZnSn2E3 rings exhibit twist boat conformation. The presence of the molecular structures in solution is confirmed by Sn-119 and Se-77 NMR spectroscopy. Cothermolysis experiments using a mixture of complexes 1-R or 2-R and [(iPr(3)PCu)(2)(EC2H4E)](2) as a copper source were monitored by thermogravimetry and temperature dependent X-ray powder diffraction to examine the thermolysis reaction. According to Rietveld refinement, the solid residue consists of Cu2ZnSnS4 (up to 78 wt %) or Cu2ZnSnSe4 (up to 43 wt %) as the main product, respectively.