Synthesis and crystal structures of tellurium complexes containing imidophosphinate ligands

The synthesis of TeL2 complexes for a variety of imidophosphinate ligands [R-2(E)PNP(E)R-2'](-) (E = S or Se) is described. The crystal structures of ve examples are reported. Generally the complexes adopt square planar geometries but in one case [R = Et, R' = OPh] two-coordinate geometry is observed. It appears that electronic effects are more important in controlling geometry than steric effects. Two examples of five-coordinate TeL(C6H4OCH3)Cl-2 complexes have also been prepared and structurally characterised.