Abstract: The photolysis of Mn₂(CO)₁₀ isolated in Ar and Xe matrices at 10 Khas been studied with 280 nm and 355 nm UVpulsed laser and Fourier-transformed infrared spectroscopy.The changes in the IRspectra of the Mn₂(CO)₁₀ after photolysis and its dependence on the matrices, irradiation time, laser wavelength and the concentration COdoped in the matrix have been examined.The experimental results show that in solid argon matrix the primary product of the dissociation of Mn₂(CO)₁₀ is Mn₂(CO)₉, and in solid xenon matrix, Mn(CO)₅ is also observed.The dissociation yield in the xenon matrix is higher than that in argon matrix.Due to the matrix cage effect, the photofragments can recombine, the yield of Mn₂(CO)₉ is related to the COconcentration in matrix, whereas that of Mn(CO)₅ is independent on COconcentration.Based on the COdependence of the absorption intensities of the IRband of the reaction products, the conclusion that in xenon matrix the absorption at 2056.3, 2030.9, 1998.8, 1974.5 and 1764.1 cm^-1 are the vibrational bands of Mn₂(CO)₉ and 1991.9 cm^-1 is that of Mn(CO)₅ has been reached.The 280 nm pulsed laser is more effective on photolyzing Mn₂(CO)₁₀ and generating Mn₂(CO)₉ than 335nm pulsed alser.

Key words: Matrix isolation at low temperature, Mn₂(CO)₁₀, Laser photolysis