title: An investigation into the photochemistry of, and the electrochemically induced CO-loss from, [(CO)5MC(OMe)Me](M = Cr or W) using low-temperature matrix isolation, picosecond infrared spectroscopy, cyclic voltammetry, and time-dependent density functional theory.
abstract: The photophysics and photochemistry of [(CO)5MC(OMe)Me] (M = Cr or W) were investigated using picosecond time-resolved infrared spectroscopy (M = Cr or W), low-temperature matrix isolation techniques (M = Cr), and time-dependent density functional calculations (M = Cr or W). These studies provide unambiguous evidence for the photochemical formation of a long-lived, 18-electron metallaketene species capable of acting as a synthetically useful intermediate. For the Cr complex, an intermediate metallacyclopropanone singlet excited state was detected on the reaction path to the metallaketene species. This metallacyclopropanone excited state species has a lifetime of less than 100 ps and a characteristic bridging carbonyl band at 1770 cm(-1). The tungsten ketene species was also detected but in contrast to the chromium system, this forms directly from a low-lying triplet excited state. The electrochemical release of CO showed a greater efficiency for the chromium complex when compared to the tungsten.
authors.affiliation: School of Chemical Sciences, Dublin City University, Dublin 9, Ireland. mary.pryce@dcu.ie.
authors.forename: Suzanne
authors.initials: S
authors.lastname: McMahon
authors.forename: Saeed
authors.initials: S
authors.lastname: Amirjalayer
authors.forename: Wybren J
authors.initials: WJ
authors.lastname: Buma
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Halpin
authors.forename: Conor
authors.initials: C
authors.lastname: Long
authors.forename: A Denise
authors.initials: AD
authors.lastname: Rooney
authors.forename: Sander
authors.initials: S
authors.lastname: Woutersen
authors.forename: Mary T
authors.initials: MT
authors.lastname: Pryce