Bis(1-methylimidazolyl)diselenide and 1-methylimidazole-2-selenolate complexes of zinc, cadmium, and mercury: synthesis, characterization, and their conversion to metal selenide quantum dots

Abstract

Treatment of a methanolic solution of metal acetate with bis(1-methylimidazolyl)diselenide, [(MeImSe)₂], yields complexes of composition [M(OAc)₂{(MeImSe)₂}] (M = Zn, Cd, or Hg) whereas reactions of [MX₂(Me₂NCH₂CH₂NMe₂)] (X = Cl or OAc) with sodium 1-methylimidazole-2-selenolate gave selenolate complexes of the general formula [M(MeImSe)₂] (M = Zn or Cd). The complexes were characterized by elemental analysis, IR, UV-vis, NMR (¹H, ¹³C, and ⁷⁷Se) data. The crystal structure of [Cd(OAc)₂{(MeImSe)₂}] was established by single-crystal X-ray diffraction. The cadmium atom adopts a distorted octahedral configuration defined by asymmetrically chelated acetate groups and chelating diselenide ligand. Thermal behavior of adducts was studied by thermogravimetric analysis. Pyrolysis in hexadecylamine/tri-n-octylphosphine oxide gave MSe quantum dots, which were characterized by UV-vis, photoluminescence, XRD, EDAX, SAED, and TEM.