M. Schmitt et al., Determination of the structures of benzotriazole(H2O)(1,2) clusters by IR-UV spectroscopy and ab initio theory, PHYS CHEM P, 3(19), 2001, pp. 4218-4227
The structures of benzotriazole monomer and clusters have been examined by
benzotriazole(H2O)(1,2) comparison of R2PI spectra and IR-UV double resonan
ce spectra with the results of ab initio based normal mode calculations. Th
e structures of the binary benzotriazole-water cluster and the n = 2 cluste
r are shown to be cyclic. Based on these cyclic structures the intermolecul
ar vibronic transitions have been assigned by comparison with ab initio nor
mal mode analysis. The cyclic clusters can be viewed as a benzotriazole(H2O
)(1,2) precursor to a transition state for H-atom transfer from the 1- to t
he 2-position in benzotriazole. The activation energy for this tautomerism
has been calculated for the monomer and the n = 1 and 2 cluster as the diff
erence between the stabilization energy of the more stable tautomer and the
respective transition state. It has been found to decrease rapidly, with i
ncreasing cluster size.