Investigation of the solvent free isomerisation of cis-Mo(CO)4L2 [L = PPh2Et, PPh3, PPh2Me, and P(m-tolyl)3] by diffuse reflectance infrared Fourier transform

Abstract

Thermal analysis of cis-Mo(CO)₄L₂ [L= PPh₂Et, PPh₃, PPh₂Me and P(m-tolyl)₃] revealed that they undergo cis to trans isomerisation under solventless conditions. For L = PPh₃ and P(m-tolyl)₃, the reaction occurred in the solid state. For L = PPh₂Et and PPh₂Me the reaction occurred in the melt and was followed by trans isomer solidification. The rate of the solid state isomerisation of cis-Mo(CO)₄ (PPh₃)₂ was investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and the results showed that the reaction was first order. A thermomicroscopic investigation of cis-Mo(CO)₄[P(m-tolyl)₃]₂ revealed that the isomerisation was surface-initiated.

KEY WORDS: Solventless reactions, Molybdenum, Isomerisation, Thermal analysis

Bull. Chem. Soc. Ethiop. 2011, 25(2), 209-220.