Photochemistry of tricarbonyl(1–6-η-cycloheptatriene)-molybdenum in frozen gas matrices at 12 K. Photodissociation of cycloheptatriene and carbon monoxide ligands

Abstract

Infrared spectroscopic studies reveal that u. v. irradiation of [Mo(η⁶-C₇H₈)(CO)₃](1) in CH₄ and Ar matrices at 12 K results in the reversible formation of [Mo(η⁶-C₇H₈)(CO)₂]via photodissociation of CO. Energy-factored force field fittings show that the species [Mo(η⁶-C₇H₈)(CO)_{3 –n}(¹³CO)_n](n= 1–3) and [Mo(η⁶-C₇H₈)(CO)_{2 –m}(¹³CO)_m](m= 0–2) are produced on prolonged irradiation of (1) in a ¹³CO doped (5%) CH₄ matrix at 12 K. Photolysis of (1) in a N₂ matrix at 12 K leads to photoproducts of the type [Mo(η⁶-C₇H₈)(CO)_{3 –x}(N₂)_x](x= 1–3). Stepwise photoelimination of cycloheptatriene in a CO matrix at 12 K results in the conversion of (1) to [Mo(CO)₆]via the intermediate species [Mo(η⁴-C₇H₈)(CO)₄].