Synthesis, spectroscopic, DFT and optoelectronic studies of 2-benzylidene-3-hydroxy -1-(5,6-diphenyl-1,2,4-triazine-3-yl)hydrazine metal complexes

Abstract

Metal complexes of Ni(II) and Cu(II) with a new Schiff base, 2-benzylidene-3-hydroxy -1-(5,6-diphenyl-1,2,4-triazine-3-yl)hydrazine (HBDHT) have been synthesized and characterized by elemental analysis and spectroscopic methods. The results adopt octahedral and square planar structures for Ni(II) and Cu(II) complexes, respectively with the formula, [Ni(BDHT)(NO3)(H2O)2)]·H2O and [Cu(BDHT)(H2O)](NO3)·H2O. The emission spectra arising from S1 state is assigned to π∗ →π and LUMO→HOMO transition character for investigated molecules. Structural parameters of the synthesized compounds were calculated on the basis of DFT level implemented in the Gaussian 09 program. The size of the prepared nano particles was obtained by scanning electron microscopy (SEM) and particle size analyzer. Analysis of the absorption coefficient near the fundamental absorption edge emphasizes two indirect allowed transitions n → π∗ and π → π∗ with energy gaps of 1.1 and 2.55 eV. The forward bias current of the prepared heterojunction shows diode-like behavior with appreciable rectification characteristics. The extracted heterojunction parameters show light dependence which supporting the achievability for the optical sensor in several optoelectronic applications.