Photodissociation of methylnitrite: State distributions, recoil velocity distribution, and alignment effects of the NO(<i>X</i> 2Π) photofragment

Abstract

The photodissociation of CH3ONO→CH3O+NO at 363.9 nm generates vibrationally, rotationally, and translationally excited fragments (fNOvib =3%, fNOrot =15%, fNOtrans =33%). By means of two-photon LIF and sub-Doppler spectroscopy in combination with various polarization schemes of dissociation and probe lasers, the nascent NO(X 2Π) photofragment was characterized with respect to state distributions and three-dimensional recoil velocity distribution. Furthermore, the rotational alignment and the Λ-state populations were determined. Through the rotational alignment dependence of Doppler profiles probed by differently polarized transitions (R and S), the J–v vector correlation was assessed. Based on these results, stereochemical and dynamical information about the dissociation was obtained which shows that the fragmentation process is planar and takes place within 210 fs.