A Highly Efficient Salen‐Palladium Complex as a Homogeneous Catalyst for the Suzuki–Miyaura Coupling Reaction: DFT, Photoluminescence, and Electrochemical Properties

Abstract A mononuclear palladium complex based on N, N ‐bis(3‐ethoxysalicylidene)ethylenediamine(H 2 L) ligand and complex were synthesised and characterised using 1 H‐NMR, FT‐IR and UV–visible spectroscopic techniques. ESI‐Mass spectroscopy revels the stoichiometry of the complex as [PdL]. The Thermogravimetric analysis (TGA) indicates that the palladium complex is stable up to 375 °C. The Density Functional Theory (DFT) used to determine the quantum chemical parameters of the ligand and the complex. The HOMO‐LUMO energy gap of the palladium complex is found to be 3.346 eV. The simulated UV–visible absorption spectra of ligand and the palladium complex using Time Dependent‐Density Functional Theory (TD‐DFT) shows close agreement with experimentally obtained absorption spectra. The cyclic voltammetry of the palladium complex displays a one‐electron quasi‐reversible peak (E 1/2 = −1.284 V) corresponding to Pd(II)/Pd(I) redox cycle. The complex exhibit photoluminescent behavior with blue emission at 485 nm. The palladium complex catalyzes Suzuki coupling reaction with 0.2 mol% catalyst loading in aqueous ethanol resulting in significant product yield of 86–99%.