SYNTHESIS OF PHOSPHINOCHALCOGENOIC AMIDATO COMPLEXES OF DIVALENT TRANSITION-METALS AND THEIR THERMOLYSIS TO METAL SELENIDE AND TELLURIDE PHASES

Protolysis of the transition-metal diamides [M{N(SiMe3)(2)}(2)(thf)(n) ] (M = Cr, Mn. Fe or Co) with 2 equivalent's of phosphinochalcogenoic amides (Bu2P)-P-t(E)NHR (E = Se or Te, R = Pr-i or cyclo-C6H11) pave a series of thermally stable metal-selenium and -tellurium complexes [M {(Bu2P)-P-t(E)NR}(2)]. The complex [Ni{(Bu2P)-P-t(Se)NR}(2)] was obtai ned from Li[Bu-2(t)(Se)NR] and [NiCl2(PMe3)(2)]. The compounds sublime readily under reduced pressure and are suitable for the gas-phase dep osition of metal chalcogenide films, The selenium precursors lead to M Se (M = Cr, Mn, Fe or Ni), while tellurium complexes afford MTe2 (M = Fe, Mn or Co). By contrast, [Co{(Bu2P)-P-t(Se)NR}(2)] gives Co3Se4, wh ile [Ni{(Bu2P)-P-t(Se)NR}(2)] generates NiSe or Ni6Se5, depending on t he deposition conditions.