Copper(I) 2-pyridyl selenolates and tellurolates: synthesis, structures and their utility as molecular precursors for the preparation of copper chalcogenide nanocrystals and thin films

The complexes, [Cu{EC(5)H(3)(R-3)N}](4) (E/R = Se/Me or Te/R; R = H or Me) were isolated by the reaction between CuCl and NaEC(5)H(3)(R-3)N and were characterized by elemental analyses, uv-vis and NMR ((1)H, (13)C) spectroscopy. The crystal structures of [Cu{SeC(5)H(3)(Me-3)N}](4) and [Cu(TeC(5)H(4)N)](4) revealed that the molecules are tetrameric in which each copper atom lies at the vertex of the tetrahedron and each face of the tetrahedron is capped by the bridging pyridylchalcogenolate ligand. Thermal behavior of these complexes was studied by thermogravimetric analysis. Depending on reaction conditions, thermolysis gave both stoichiometric and non-stoichiometric copper chalcogenides, which were characterized by XRD, EDX, SEM, TEM and SAED techniques. These precursors were used for the preparation of nanocrystals and for deposition of thin films of copper chalcogenides by AACVD (Aerosol Assisted Chemical Vapor Deposition).