Phosphine photolabilisation studies of (η5-C5H5)Fe(PPh3)(CO)COR (R = Me, Ph, 2,6-C6H3F2) and (η5-C5Me5)Fe(PPh3)(CO)COR (R = Me, 2,6-C6H3F2) utilising NMR, laser desorption FT ICR MS and photofragmentation voltammetry analysis

Abstract

Photolysis of (η⁵-C₅Me₅)Fe(CO)(PPh₃)COR (R = 2,6-C₆H₃F₂, Me) leads to preferential loss of the phosphine ligand to form the corresponding alkyl species (η⁵-C₅Me₅)Fe(CO)(PPh₃)R, while photolysis of (η⁵-C₅H₅)Fe(CO)(PPh₃)COR (R = Me, Ph, 2,6-C₆H₃F₂) leads to loss of CO to form (η⁵-C₅H₅)Fe(CO)(PPh₃)R which subsequently undergoes rapid phosphine exchange. A mechanism for this process is proposed which is corroborated using photofragmentation voltammetry. Laser desorption mass spectrometry was also used as a tool to probe whether phosphine loss was the primary photochemical process.