Synthesis of Novel Tetrazole Transition Metal Complexes for Advanced Photonic Applications

Abstract

As tetrazole themselves revealed a rich photochemistry and are piquantly affected by the presence of substituents on tetrazole ring. This exertion explores the harmony of two bidentate ligands-pyridine tetrazole (Hpytz) and pyridine tetrazole-N-oxide (Hpytzo) as "antennae" and their complexes with transition metals (Fe³⁺, Co²⁺, Ni²⁺, Zn²⁺ and Ru³⁺). The erections of these pyridine tetrazole metal complexes were elucidated by UV, IR and ¹H NMR by using DMSO, acetonitrile as solvents in which these metal complexes persist in undissociated form and also show high melting point >360 ºC. These pyridine tetrazole ligands ("antennae") sensitize efficiently the metal centre and stimulus the absorption window of pyridine tetrazole transition metal complexes, which was appreciably stretched towards the UV-visible region of 400-800 nm. The wavelength of these ligands l_emission was found to be amplified upto 522-540 nm (l_excitation = 270 nm) that might enlightens the extremely conjugated unsaturated system which triggers the UV-region and for metal complexes (l_excitation, Fe³⁺ = 270 nm, Co²⁺ = 280 nm, Ni²⁺ = 285 nm, Zn²⁺ = 270 nm and Ru³⁺ = 260 nm (l_emission, Fe³⁺ = 522.5 nm, Co²⁺ = 576 nm, Ni²⁺ = 554 nm, Zn²⁺ = 521 nm and Ru³⁺ = 522 nm). The escalation in l_{emission of the metal complexes} with novel designed tetrazole ligands spectacles a drift on complex formation due to the augmented conjugation and conformation, which might sensitizes luminescence properties as reported with La(III) complexes more proficiently. The fluorescent property revealed with these neutral pyridine tetrazole derivatives stipulate an efficient alternative to that of usual dipicolinate analogues.