Raman-scattering of alpha-copper phthalocyanine and other complexes formed at a silver surface using a compacted electrode

A novel compacted electrode technique is used to obtain a layer of the insoluble pigment α-copper phthalocyanine on a silver surface. Electrochemical treatment improves the signal to noise ratio of the Raman spectrum of the phthalocyanine at the surface and a selective enhancement of some bands indicates a SERS effect as well as resonance. Silver phthalocyanine can be synthesised at a silver surface using compacted electrodes of silver and either metal-free phthalocyanine or o-phthalonitrile. The formation of the layer of complex at the surface can be observed by Raman spectroscopy. The method was extended to a non-phthalocyanine system using a silver/bipyridyl compacted electrode, which gave a detectable layer of a silver bipyridyl complex at the electrode surface and a solution of a soluble silver bipyridyl complex. This combination of a compacted electrode and Raman spectroscopy appears ideal for the synthesis and characterization of a range of transition-metal complex/metal surfaces.