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

propanone 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.

Recent advances in ketene chemistry

“…54 Ketene IR bands using isotope-labeled ices of methanol-carbon monoxide were also identified at 2107 cm An independent study 56 of this system as well as of the corresponding tungsten complex found that, in contrast to the previous work, which indicated triplet states in the case of the chromium complex, no evidence for the formation of triplet states was observed. The later investigators preferred the reaction path forming structures 53 and 54 (Scheme 27 Carbon monoxide reduction by lithium disilenide 57 forms a silanone dimer 59 proposed to form through the ketenyl intermediate 58.…”

Photo‐ and Electrochemical Properties of a CO2 Reducing Ruthenium–Rhenium Quaterpyridine‐Based Catalyst

“…The ps‐TRIR apparatus was previously reported by us, but a general overview is as follows . UV pump and mid‐IR probe pulses were generated by a Ti : sapphire laser (repetition rate 1 kHz).…”

Excited‐State Reactivity of [Mn(im)(CO)3(phen)]+: A Structural Exploration

“…Knowing the essential role of manganese in biological processes a number of studies has been dedicated to [Mn(CO) 3 (bpy/phen)(L)] 0/+ complexes. The photo‐reactivity of this class of first‐row transition metal complexes on irradiation in the visible has been associated to the presence of low‐lying metal‐centered (MC) states in the vicinity of the MLCT absorbing states . Whereas extensive work, both experimental and theoretical, has been achieved on third‐row analogues to understand and interpret the spectroscopy and the photophysics of the usually nonreactive [Re(CO) 3 (bpy/phen)(L)] 0/+ compounds, little is known on the optical and photophysical properties of [Mn(CO) 3 (bpy/phen)(L)] 0/+ complexes.…”