Synthesis of phosphinochalcogenoic amidato complexes of divalent transition metals and their thermolysis to metal selenide and telluride phases

Abstract

Protolysis of the transition-metal diamides [M{N(SiMe 3 ) 2 } 2 (thf) n ] (M = Cr, Mn, Fe or Co) with 2 equivalents of phosphinochalcogenoic amides Bu t 2 P(E)NHR (E = Se or Te, R = Pr i or cyclo-C 6 H 11 ) gave a series of thermally stable metal–selenium and –tellurium complexes [M{Bu t 2 P(E)NR} 2 ]. The complex [Ni{Bu t 2 P(Se)NR} 2 ] was obtained from Li[Bu t 2 (Se)NR] and [NiCl 2 (PMe 3 ) 2 ]. The compounds sublime readily under reduced pressure and are suitable for the gas-phase deposition of metal chalcogenide films. The selenium precursors lead to MSe (M = Cr, Mn, Fe or Ni), while tellurium complexes afford MTe 2 (M = Fe, Mn or Co). By contrast, [Co{Bu t 2 P(Se)NR} 2 ] gives Co 3 Se 4 , while [Ni{Bu t 2 P(Se)NR} 2 ] generates NiSe or Ni 6 Se 5 , depending on the deposition conditions.