Neon matrix experiments

These findings indicate general difficnlties in interpreting the results of flash photolysis experiments with UV visible detection. First, no detailed structural information can be obtained. Second, minnte traces of imparity in the solvent interfere strongly with the spectral behavior. It has now become clear that Cr(CO)s (and other unsaturated carbonyls) are almost always complexed by solvent or matrix molecnles or atoms. Even in a neon matrix there is some interaction to produce the species Ne- Cr(CO)5. Naked Cr(CO)s can be made in the gas phase, and by some rather cunning time-resolved solution experiments. Here, solvated Cr(CO)s is formed by UV photolysis of Cr(CO)6, then the solvating molecule is removed by visible photolysis. Fast time-resolved spectroscopy allows the decay of the naked Cr(CO)s, as it resolvates, to be moiutored. It is clear that this decay is extremely rapid. 

The naphthalene cation has been studied by absorption spectroscopy in solutions [154,155], glasses [156-159], and matrices [160]. Gas-phase data stem from PES [161,162] and multiphoton dissociation [163,164] spectra. Recently, the 180- to 900-nm absorption spectrum of naphthalene formed by photoionization in a neon matrix has been reinvestigated [165]. These experiments show seven progressions, with peak maxima at 1.84, 2.72, 3.29, 4.06, 4.49, 5.07, and 5.57 eV. The excitation energies calculated by Schutz et al. for the cation geometry are shown in Table XIV. They are in agreement with experiment. The largest deviation amounts to 0.13 eV (2 B2g). Table XIV also shows the predicted PES, which matches experiment. 

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