A new mixed-ligand zinc(II) complex of 3-hydroxy and 4-chloro substituted pyridine-2-carboxylic acid: Synthesis, characterization, NLO properties and DFT calculation

Abstract

Molecular engineering of metal-organic frameworks has recently attracted increasing attention due to their potential technological applications in the fields of optics and photonics. In addition to improved optical properties, the incorporation of metal ions into organic ligands makes it possible to control the intensity and polarization of the incident laser light. This makes organometallic complexes valuable and suitable candidates for nonlinear optical applications. In this study, a novel Zn(II) complex was synthesized by using 4-chloropyridine-2-carboxylic acid (4-Clpca) and 3-hydroxypyridine-2-carboxylic acid (3OHpca). The structural and spectroscopic properties of the Zn(II) complex were examined through XRD, FT-IR and UV-Vis techniques. The HOMO-LUMO energy range for the Zn(II) complex was found to be 4.7358 eV. Nonlinear optical parameters of Zn(II) complex were investigated as static and frequency-dependent (ω = 0.0856453887 au) methods. The dc-Kerr effect γ(-ω;ω,0,0) and EFSHG γ(−2ω;ω,ω,0) parameters were calculated as 13.04 × 10−36 esu and 2258.9 × 10−36 esu, respectively. The newly synthesized Zn(II) complex, which has weak second-order NLO properties due to the fully occupied electronic configuration of the Zn(II) ion, is quite promising in terms of its third-order optical properties.