Bio‐derived nanosilica‐anchored Cu(II)‐organoselenium complex as an efficient retrievable catalyst for alcohol oxidation

Abstract

A new copper(II) complex supported onto rice‐husk‐derived nanosilica was prepared from 2,6‐bis((phenylselanyl)methyl)pyridine, salicylaldehyde and copper acetate monohydrate, Cu(OAc)2·H2O. The as‐synthesized complex Cu(II)SeNSe@imine‐nanoSiO2 (Complex I) was extensively characterized with FT‐IR, powder XRD, SEM‐EDX, solid‐state UV‐Vis, ESR, XPS, TGA and BET surface area analysis. The catalytic activity of the complex was explored for alcohol oxidation reactions using H2O2 as oxidant and acetonitrile as solvent. For comparison, we have also prepared an analogous homogeneous catalyst (Complex II) and characterized it with FT‐IR, UV‐Vis, LC‐MS and ESR analyses. Its catalytic activity was also screened to the same reaction. The immobilized catalyst showed better efficiency with 75%–95% isolated yield compared with the homogeneous one for alcohol oxidation with at least five times recyclability without profound loss in activity.