Stereodynamics of photochemical reactions

The latest results obtained from investigating vector correlations in the p hotodissociation of di- and triatomic molecules are reviewed. Expressions f or the polarization moments of atoms formed as a result of the photodissoci ation of an arbitrary molecule by polarized radiation, which depend on spat ial and spin variables, are presented. The set of anisotropy parameters, wh ich can be determined experimentally and then utilized to obtain a complete quantum-mechanical description of the primary photodissociation act, is di scussed. Two methods for determining the orientation parameters, alignment parameters, and higher polarization moments of atomic photofragments are co nsidered. They are based on a) ion imaging, which involves laser photoioniz ation followed by mass-spectrometric detection of the photofragments and b) sub-Doppler laser polarization spectroscopy of the photofragments. The res ults of an experimental study of the photodissociation of Cl-2 molecules, w hich leads to the formation of Cl(P-2(3/2)) atoms with aligned electronic a ngular momenta, are presented as an example. (C) 1999 American Institute of Physics. [S1063-7842(99)01009-0].