Synthesis, Characterization and Density Functional Theory (DFT) study on the Zinc Metal Complex for Nonlinear Optical Application
DOI:
https://doi.org/10.11113/jomalisc.v2.39Keywords:
Nonlinear optics, metal variation, DFT, FTIR, NMR, optimizationAbstract
Schiff base metal complexes are well-known for its nonlinear optics (NLO) properties. However, different metals may show different NLO properties. In this study, zinc (Zn) metal, N,N-bis[2-(diphenylphosphino)benzylidene]cyclohexane-1,2-diamine ligand was selected. The ligand was synthesized at room temperature while stirring for 24 hours, using dichloromethane (CH2Cl2) as the solvent. Complexation of the selected metals (Zn) were later carried out with the ligand under inert conditions, N2 gas refluxed for 12 to 24 hours in solvent. The percentage yield of products was 38 %. The types of characterization involved in this study were Fourier transform infrared (FT-IR), and nuclear magnetic resonance (NMR). Computational studies were also performed to optimize the structure of ligand and metal complexes using density functional theory (DFT) method with basis set 6-31G and hybrid functional B3LYP. The data obtained from both experimental and computational methods were compared. To confirm nonlinear optic properties, one can use the HOMO-LUMO energy gap. Our choice of metal complex of zinc with organic ligand was based on the excellent NLO characteristics of transition metal based organic compounds. Transition metal-based complexes yield impressive results because they offer additional flexibility by offering charge transfer between the metal and the ligand, resulting in a higher NLO response. It was discovered that the zinc complex with the lower band gap of 1.69 eV particularly in comparison with the ligand 2.44 eV. Thus, the lower the band gap, the higher the NLO properties of the compound.
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