Copper (II) and Palladium (II) Schiff‐Base Complexes as Homogeneous and Heterogeneous Catalyst for Efficient α‐Methyl Oxidation Reaction: Experimental and DFT Approaches

Abstract

AbstractNew homogenous catalysts of Schiff base/M(II), (M(II)=Cu, Pd), and new heterogeneous catalysts [graphene oxide (GO)/3‐chlorotrimethoxisilane (CPS) /Schiff base/M(II)] has been successfully synthesized. The heterogenous catalysts were synthesized using 3‐chlorotrimethoxisilane (CPS) via covalent bonding on graphene oxide and were characterized using fourier transform infrared spectroscopy (FTIR), x‐ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x‐ray spectroscopy(EDS) techniques. Schiff base/M(II) and GO/CPS/Schiff base/M(II) were used as homogenous and heterogeneous catalysts in the oxidation of alkens. Catalytic results showed all the prepared samples were active in the oxidation of α‐methyl styrene. Over as‐prepared heterogeneous catalysts, more than 99 % conversion and selectivity for acetophenone could be achieved using (tert‐butyl hydroproxide (TBHP) : 22.5 mmol, Acetonitrile as solvent after 6 h).The recyclability experiment results indicated that heterogenous catalysts are excellent for α‐methyl styrene conversion and acetophenone selectivity even after being used for four cycles. Moreover, the electronic structures and net atomic charges are interpreted by density functional theory (DFT) calculations. Running title: Copper (II) and palladium (II) Schiff base complexes for experimental and theory study