Photolysis of dimethylnitrosamine in the gas phase

Abstract

AbstractPhotodecomposition of dimethylnitrosamine in the gas phase ( ∼ 1 Torr) has been investigated following irradiation into the S1 (nπ*) ← S0 (363.5 nm) and S2 (ππ*) ← S0 (248.1 nm) transitions at room temperature. With a quantum yield of unity, excitation into the S1 state yields the fragments (CH3)2N⋅ and NO which then recombine leaving no photoproducts. The addition of O2 results in only one photoproduct, (CH3)2NNO2. Irradiating into the S2 state, the products CH2NCH3, (CH2NCH3)3, CH2NOH, N2O, NO, H2, and N2 were identified by capillary gas chromatography mass spectrometry. In the presence of N2 as a buffer gas the photoproducts are only CH2NCH3, (CH2NCH3)3, N2O, and H2. For both excitation conditions a mechanism is proposed involving cleavage of the N, N‐bond as the main primary photolytic process.