FOURIER-TRANSFORM INFRARED SPECTROSCOPIC STUDIES OF CHARGE-TRANSFER INTERCALATION COMPOUNDS

Fourier transform infrared spectroscopy has been used to characterize the charge-transfer nature o cobaltocene, Co(C5H5)2, intercalated into the layered host lattices Cd2P2S6 and SnS2. In the Cd2P2S6 case, the infrared spectrum is consistent with the presence of both neutral cobaltocene and cationic cobaltocenium, CO(C5H5)2+1. Spectra taken after a reaction time of several hours as well as several weeks both lead to the same conclusion. Spatially resolved infrared spectra suggest that the intercalation reaction is a charge-transfer reaction followed by diffusion of neutral cobaltocene into the Cd2P2S6 host. In the SnS2 case, the infrared spectrum is consistent with the presence of only the cationic form of the cobaltocene with no evidence that neutral cobaltocene remains within the host. Electron spin resonance spectroscopy was used to further substantiate these conclusions.