Cobalt(III) complexes of neutral selenium and tellurium donor ligands: synthesis and nuclear magnetic resonance studies
Abstract
The first examples of diseleno- and ditelluro-ether complexes of cobalt(III), [Co(MeSeCH2CH2SeMe)2X2]BPh4(X = Cl, Br, or I) and [Co{o-C6H4(TeMe)2}2X2]BPh4(X = Br or I), have been prepared by air oxidation of mixtures of anhydrous CoX2, ligand, and NaBPh4 in nitromethane. The complexes have been characterised by u.v.–visible and multinuclear n.m.r. (59Co, 77Se-{1H}, and 125Te-{1H}) spectroscopy. The iodo complexes are trans isomers, but both cis and trans forms are present with the other halides.