Photodissociation dynamics of nitrotoluene at 193 and 248 nm: Direct observation of OH formation

The photodissociation of nitrotoluenes at 193 and 248 nm was investigated, employing laser photolysis–laser induced fluorescence technique. OH was observed as a photoproduct on photodissociation of only o-nitrotoluene. At both the wavelengths of photolysis, OH was formed in both vibrationally ground state, v″ = 0, and the excited state, v″ = 1. The energy partitioned as translational energy of the photofragment, on photolysis at 193 and 248 nm, was found to be 15.2 ± 4.0 and 16.0 ± 3.5 kcal/mol, respectively. No preferential population of spin orbit states was observed at both the wavelengths. However, Λ-doublet states show non-statistical distribution at 248 nm photolysis. Various channels of dissociation leading to OH are examined. Based on partitioning of translational energy and Λ-doublet states ratios, OH formation is attributed to different isomers at two wavelengths.