Chemistry of Thermally Generated Transient Phosphanoxyl Complexes

Investigations on the reactivity of the transiently formed phosphanoxyl complex [(CO)₅W­(Ph₂PO^•)], thermally generated from [(CO)₅W­(Ph₂PO-TEMP)] in toluene, is presented. Apart from self-reactions, trapping of this radical complex was achieved using group 14 hydrides Ph₃EH (E = Si, Ge, Sn), leading to new phosphane complexes possessing a P–O–EPh₃ bonding motif and the corresponding TEMP-H as byproduct. Reaction pathways, derived from DFT calculations, clearly revealed the intermediacy of various open-shell complexes; EPR measurements showed the presence of radicals, but unfortunately interpretation was not achieved.