Synthesis of novel Zn(II) and Cd(II) complexes of semicarbazones and their utility as precursors for respective metal selenide quantum dots

Abstract

This paper describes synthesis, characterization and applications of a series of new bis ((Z) (amino (2-cyclo alkylidenehydrazinyl) methylene) oxonio) zinc and bis ((Z) (amino (2-cycloalkylidenehydrazinyl) methylene) oxonio) cadmium complexes from cycloalkeno-semicarbazones and corresponding metal salts. These complexes were characterized by UV–Vis, IR, NMR spectroscopy and mass spectrometry as well as by elemental analysis and thermo gravimetric analysis (TGA). The reduction and oxidation behavior of complexes were examined by cyclic voltammetry. The synthesized complexes were reacted with organoselenium compounds e.g. 1,2,3-selenadiazoles to isolate ZnSe and CdSe quantum dots via thermal reaction employing octadecenoic acid. The synthesized quantum dots (QDs) were analysed by UV–Vis, Photoluminescence spectroscopy, XRD measurement and TEM/EDAX analysis. QDs of less than 5nm in diameter with narrow size distributions were isolated. Such new metal precursors and combining them with organometallic Se-reagent leads to selective formation of regular quantum dots only.