2-Pyridyl selenolates of antimony and bismuth: Synthesis, characterization, structures and their use as single source molecular precursor for the preparation of metal selenidenanostructures and thin films

Abstract

Reactions of SbCl₃ and BiCl₃ with M′Se–C₅H₃(R-3)N (M′ = Li or Na; R = H or Me) gave homoleptic selenolate complexes of the general formula [M{Se–C₅H₃(R-3)N}₃] (M = Sb or Bi). The complexes were characterized by elemental analysis, UV-vis and NMR (¹H, ¹³C and ⁷⁷Se) spectroscopy. The single crystal X-ray analysis of [M{Se–C₅H₃(Me-3)N}₃]·nH₂O (M/n = Sb/1.5 and Bi/0.5) revealed that the antimony complex adopts a trigonal pyramidal configuration with monodentate selenolate ligands while the bismuth analogue acquires a distorted square pyramidal configuration defined by two chelating and one monodentate selenolate groups. Pyrolysis of [M{Se–C₅H₃(Me-3)N}₃] either in a furnace or in hexadecylamine (HDA) at different temperatures gave a variety of M₂Se₃ nanostructures. Thin films of metal selenides have also been deposited on glass substrate by aerosol-assisted chemical vapor deposition (AACVD). Both nanostructures and thin films of metal selenides were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM).