High nonlinear optical efficiency in zinc(II) and copper(I) stilbene based iminopyridine complexes: Absorption, emission analysis and advanced characterization

Abstract

The novelty of this work lies in the comprehensive studies of the spectroscopic and third-order nonlinear optical properties of zinc(II) and copper(I) stilbene based iminopyridine complexes. Our previous work involved the synthesis as well as the characterization of both the free ligand and these its corresponding metal complexes and conducting quantum chemical calculations on their molecular orbitals, shedding light on their charge transfer and π-π* interactions. This makes these materials promising models for supramolecular assemblies. Thin films, obtained using the spin coating method, are characterized using Atomic Force Microscopy and Ellipsometry methods. These techniques provide valuable information about the physical properties of the layers, such as homogeneity, roughness and linear refractive index. Moreover, we present spectroscopic analysis that involve the absorption and emission of light, along with the decay time of photoluminescence in the thin films. Through advanced techniques like the Maker fringe method for third harmonic generation and the Z-scan method for recording nonlinear absorption and refraction, we demonstrate the high nonlinear optical efficiency of these complexes. This study presents how specific structural elements impacts tailoring in the enhancement of the NLO properties of these complexes. These findings underscore the potential of zinc(II) and copper(I) stilbene based iminopyridine complexes in nonlinear optics and photonics applications.