Direct determination of the reaction volume of an organometallic reaction at very high dilution

Abstract

In n-hexane, under Ar (1atm) and 298.15 K, Rh 4(CO) 12 and PPh 3 react to form a mono-substituted Rh 4(CO) 11PPh 3 and gaseous CO. This stoichiometric reaction was followed using in-situ FTIR. The concentrations of the organometallics were in the 10s of ppm range. Simultaneously, very precise online density measurements were made. Based on mass injection, partial molar volumes of reactive species were directly determined from multi-component reaction mixtures. These partial molar volumes were in good agreement compared to those of separate binary system study. Subsequently, the reaction volume was determined. From spectral analysis, not only the progress of reaction can be monitored, but also the pure component spectra of each existing species in the reaction can be recovered. The results from spectral analysis were used to confirm the reaction.