Photophysical properties and theoretical investigations of newly synthesized pyrene-naphthalene based Schiff base ligand and its copper(II) complexes

Abstract

The present work describes the synthesis and characterization of a novel pyrene-naphthalene based Schiff base ligand and its copper complexes. The ligand was synthesized by reacting 1-Pyrenecarboxaldehyde and 1,8-Diaminonaphthalene in 2:1 M ratio. The resulting Schiff base ligand, (N1E,N8E)-N1,N8-bis(pyren-1-ylmethylene)naphthalene-1,8-diamine (BPND) was characterized by NMR (1H and 13C), FT-IR and ESI-HRMS techniques. Further, BPND was used to synthesize two Cu(II) complexes (1 and 2) in 2:1 (ligand:metal) and 1:1:1 (ligand:metal:8-hyroxyquinoline) molar ratio, and characterized using electronic absorption, fluorescence spectroscopy, in addition to aforementioned spectroscopic techniques. DFT calculations have been used in order to obtain information on quantum-molecular descriptors reflecting the local reactivity properties. DFT calculations encompassed geometrical optimizations of title molecules and calculations of molecular electrostatic potential (MEP), average local ionization energies (ALIE) and atomic Fukui indices.