Syntheses and Structures of Zinc(tmeda)bis(aryltellurolato) and its Facile Chalcogenospecific Ligand Exchange Reactivity

Anaerobic treatment of Zn(tmeda)Br 2 , where tmeda denotes N,N,N ′, N ′‐tetramethylethylenediamine, with a solution of Na(TeAr), sodium aryltellurolate, in ethanol in a 1:2 stoichiometry led to the formation of highly air sensitive Zn(tmeda)(TeAr) 2 ( 1 – 3 ), while a 1:1 stoichiometry afforded Zn(tmeda)Br(TeAr) ( 4 ). Crystallography revealed all complexes to be monomeric with four coordinate central zinc atoms bound to tmeda and two TeAr, or a TeAr and a Br ligand. Upon mixing two symmetrically substituted Zn(tmeda)(TeAr) 2 complexes in solution, 125 Te NMR revealed a facile ligand exchange providing Zn(tmeda)(TeAr)(TeAr′). In addition, Zn(tmeda)(TeAr)(TeAr′) complexes form on mixing symmetric Zn(tmeda)(TeAr) 2 complexes and (TeAr′) 2 . The lability of the zinc complexes was put to advantage in ligand‐substitution reactions wherein treatment of SnCl 4 with Zn(tmeda)(TeAr) 2 affords Sn(TeAr) 4 in excellent yields without the concurrent formation of the redox product (TeAr) 2 . The apparent lability of the Zn–Te bond prevented the volatilization of 1 – 3 for their use as chemical vapor deposition precursors for the fabrication of ZnTe thin films. On heating, to volatize the complexes, the complexes decompose to cubic ZnTe and TeAr 2 sublimes from the samples. Thermal gravimetric analysis indicates the loss of tmeda followed by the loss of TeAr 2 .