The IR spectroscopy of matrix-isolated DMZ is presented as a precursor for the analysis of DMZ photochemistry in the solid rare gases. In agreement with gas-phase work, the present study reassigns the band observed at 1309.2 cm-1, currently assigned in the matrix literature to the bending mode of the impurity methane, to the ν10 + ν14 band combination mode of DMZ. From a combination of IR absorption and UV luminescence studies, atomic zinc and a pair of methyl radicals (Zn + 2CH3) are identified as the photochemical products formed with ArF excimer laser photolysis. A concerted dissociation pathway of DMZ in solid Ar is considered to be the only mechanism leading to the production of methyl radicals in the vicinity of ground-state atomic zinc. The lack of observation of the methylzinc (CH3Zn) and methyl radicals as products is explained in terms of the rapid geminate recombination of these radicals in the matrix cage, which in turn explains the poor efficiency of DMZ dissociation in the solid. Evidence exists for the formation of secondary products with ArF photolysis, namely, the production of ethylzinc hydride and acetylene. It is proposed that the former arises from the excited-state insertion of atomic zinc into the C−H bonds of the small amounts of ethane arising from the recombination of the methyl radicals. Acetylene is a product of ArF dissociation of ethylene which results from recombination of hot methyl radicals.