Synthesis of Fluorescent Rhodium(II) and Iridium(II) Complexes Promoted by 2,6-Bistetrazolate Pyridine Ligand

Abstract

The two nitrogen and one oxygen bearing tridentate ligand (H2pytzo-2, 6-bistetrazolate pyridine oxide) have been prepared by oxidation of 2, 6-bistetrazolate pyridine and then coordinated with transition metals. The complexes of [M(pytzo)2](NHEt3)2, (M= Rh, Ir) were synthesized in good yields (50% for Rh and 47% for Ir). UV, FT-IR, 1H NMR, XRD and elemental analysis were used to determine the structure of complexes. The tetrazole groups greatly influence the absorption spectra of complexes towards the visible region (362.2nm for Rh and 357nm for Ir). Further the extended unsaturation, lone pairs and π-excessive nature of ligand promotes the fluorescence spectra upto 560nm for Rh complex and 558nm for Ir complex. The antibacterial activity results showed that K. pneumoniae and S. aureus showed maximum response followed by E. coli and B. cereus, respectively. The maximum zone of inhibition of complexes was observed at 6mg/ml concentration viz; K. pneumoniae, 13.0±1.73mm for iridium complex and S. aureus, 12.3±0.57mm for rhodium complex. Hence 2, 6-bistetrazolate pyridine oxide (H2pytzo) ligand triggers the vital applications in the complexes were useful both in biological as well as solid state devices.