Laser-induced fluorescence spectroscopy and structure of microsolvated molecular clusters. Part 1.—Structure Determined via rotational band contour analysis and semi-empirical calculation

An iterative rotational band contour simulation strategy has been applied successfully to the analysis of partially resolved rovibronic bands in the laser-induced fluorescence (LIF) spectra of 4-pyrrolidinobenzonitrile (PYRBN) and its clusters with argon, and of the ethyl 4-pyrrolidinobenzoate (PYRBEE) 1 ∶ 1 complex with water. An internally consistent set of structural parameters has been obtained which, in conjunction with the predictions of molecular mechanics (MM2) and MNDO calculations, provides experimentally based structures for the host molecules as well as their individually resolved van der Waals complexes. A broad range of simulations associated with alternative ‘trial’ structures is used to quantify the precision of the structural parameters and to indicate the sensitivity of the strategy.