Surface-Enhanced Infrared Spectral Investigations of 2,3-Bis(chloromethyl)anthracene-1,4,9,10-tetraone on Copper Nanoparticles

Abstract : Surface-enhanced infrared (IR) absorption spectroscopic technique has been employed to investigate the orientation of 2,3-bis(chloromethyl) anthracene-1,4,9,10-tetraone (BCMAT) on copper nanoparticles (NPs). Copper NPs have been prepared by the chemical reduction method. The observed ring stretching modes show higher downshifts, broader bandwidths, and higher enhancement. The observed features in out-of-plane and in-plane CH deformation modes indicate that the BCMAT molecules may be adsorbed in a "flat-on" orientation on the copper NPs. The observed lower enhancement factor of the in-plane C=O deformation mode and C=O stretching mode and the higher enhancement factor of out-of-plane C=O deformation mode elucidate that the BCMAT molecules are adsorbed on the copper NPs in a "flat-on" orientation. All these observations show that BCMAT is adsorbed on copper NPs through the pi-anthraquinone ring system in a "flat-on" orientation.