Photofragmentation dynamics of the (N2O)(2)(+) and (N2O)(3)(+) clusters: fragment N(2)O(+)A <- X spectra

Rovibrational distributions of N2O+ fragments resulting from the direct 640 nm photodissociation of mass-selected (N2O)(2)(+) and (N2O)(3+) clusters h ave been measured in a tandem mass spectrometer apparatus, via the A(2)Sigm a(+) <-- X (2)Pi predissociative transition of N2O+. The N2O+ fragments fro m the dimer are endowed with significant amounts of rotational energy (45.5 < J < 85.5) with both (2)Pi(3/2) and (2)Pi(1/2) spin-orbit substrates equa lly populated. While most of the fragments are formed in the ground vibrati onal state, a significant fraction have a single quantum of nu(1) (1126 cm( -1)) or nu(3) (1737 cm(-1)) or several quanta of nu(2) (457 cm(-1)). The N2 O+ fragments from the trimer possess significantly less rotational energy t han those from the dimer but again a significant fraction is found to be vi brationally excited. The markedly reduced rotational energy of N2O+ fragmen ts from the trimer compared to the dimer is consistent with charge and ener gy transfer processes occurring between the recoiling cluster subunits. (C) 1998 Elsevier Science B.V. All rights reserved.