Infrared spectra of Dewar 2-picoline in low-temperature argon matrices

Infrared spectra of Dewar 2-picoline, produced from 2-picoline in an argon matrix by UV irradiation, were measured. The observed bands were assigned to a single isomer, which has a C–C bridging bond and an NC–CH3 group, with the aid of DFT calculations, where the 6-31++G∗∗ basis set was used to optimize the geometrical structure. No other isomer bands were observed. The selectivity of the isomerization to Dewar 2-picoline is discussed in terms of the atomic charge distribution in electronically excited states of 2-picoline.