Photochemistry of carbonyltrinitrosylmanganese in frozen gas matrices at 20 K. Infrared spectroscopic evidence for trinitrosylmanganese, (dinitrogen)trinitrosylmanganese, and a species formed by metal-to-nitrosyl photoelectron transfer

Abstract

Infrared evidence is presented for the formation of a three-co-ordinate species, [Mn(NO)₃], on u.v. photoiysis of [Mn(CO)(NO)₃] in argon matrices, and for the formation of a four-co-ordinate species, [Mn(N₂)(NO)₃], in nitrogen matrices at 20 K. Infrared evidence, including ¹⁵NO data is also presented for the formation of [Mn(CO)-(NO)₂(NO*)], where the asterisk denotes a nitrosyl group having an unusually low value of ν(NO), on photolysis of [Mn(CO)(NO)₃] with visible radiation in both argon and nitrogen matrices. It is concluded that [Mn(CO)(NO)₂-(NO*)] belongs to a class of complexes in which photoelectron transfer has occurred, with the nitrosyl ligand (NO*) accepting additional electron density to leave an electron-deficient metal centre. The results are related to the postulate of co-ordinatively unsaturated and expanded co-ordination-shell species as intermediates in the thermal substitution reactions of [Mn(CO)(NO)₃].