State-resolved photofragmentation of [ClNO](n) van der Waals clusters in asupersonic jet

The effects of the ultraviolet laser irradiation of [CINO](n) weakly bound clusters, formed in a supersonic jet, are analyzed by considering three pro cesses: the photofragmentation of bare CINO, the Cl + CINO reaction, and NO relaxation within the cluster. The photofragmentation of jet-cooled CINO a t 355 nm produces NO(upsilon" 1) with a kinetic energy of 2240 cm(-1), a sp in-orbit preference of F-1/F-2 = 1.2, and A-doublet state preferences of IT (A")/II(A") = 2.0 and 4.0 for the F-1 and F-2 manifolds, respectively. The NO distribution of rotational states was parametrized using a Gaussian func tion centered at N = 34, with a fwhm of 17. On the other hand, the Cl + CIN O reaction, studied at a collision energy of 2780 cm(-1), gives NO(upsilon" = 1) described by a Boltzmann rotational distribution with T-rot = 950 +/- 100 K. The relative population of the NO spin-orbit states is F-1/F-2 = 2. 5, with a A-doublet state preference of n(A")/II(A') = 1.2 and E-trans(NO) of 578 cm(-1). It is found that 57% of available energy is disposed as E-in t(Cl-2). As a result of the irradiation of the [CINO],, clusters at 355 nm are observed: Holt;Boltzmann, ensembles of NO(v" = 1) and NO(upsilon" = 0) molecules described by T-rot of 310 +/- 30 and 170 +/- 25 K, respectively, with no spin-orbit or A-doublet state preferences, overlapped with a Gaussi an distribution already assigned to the NO photofragment. The relative cont ribution of the NO(v" = 1) photofragment to the spectra is drastically redu ced upon increasing the backing pressure, as it undergoes translational and rotational relaxation within the clusters. Our high-resolution studies pro vide evidence that suggests that the reaction takes place within the [ClNO] (n) clusters.