Journal of Physical Chemistry, Vol.99, No.11, 3430-3437, 1995
Electronic Spectroscopy and Excited-State Dynamics of the Kralh(X(1)Sigma(+),A(1)Pi) Van-der-Waals Complex
The laser fluorescence excitation spectrum of the KrAlH van der Waals complex, in the vicinity of the A(1) Pi-X(1) Sigma(+) (0,0) band of diatomic ALH, is presented. This species was prepared in a pulsed free jet by 193 nm multiphoton dissociation of trimethylaluminum seeded in inert gas mixtures. The KrAlH bands were found to be both rotationally resolved and diffuse. Rotational analyses were carried out for most of the sharp bands. In contrast to the analogous ArAlH complex, the only observed bands from the ground KrAlH(X) bend-stretch level involved perpendicular [P’ = 1 <-- P " = 0] transitions. In addition, six hot bands were observed and allowed determination of the spacing between the lowest P " = 0 and 1 levels. It was possible to assign the bend and van der Waals stretch vibrational quantum numbers for the observed KrAlH(A) bend-stretch levels by comparison with previous experimental studies in our laboratory on the isovalent ArBH and ArAlH complexes and concurrent theoretical calculations by Alexander and co-workers on these systems.
Keywords:SHELL VANDERWAALS COMPLEXES;LASER-INDUCED FLUORESCENCE;POTENTIAL-ENERGY SURFACES;OH-AR;VIBRATIONAL PREDISSOCIATION;SCATTERING;A2-SIGMA+;SPECTRA;X(2)PI;ATOM