Intensities vibronic

Figure 5-1. Mass resolved excitation spectrum of bare aniline in a molecular jet. Several of the more intense vibronic transitions are assigned. 

Cr +) have been probed by absorption and luminescence spectroscopy. The strongest interaction occurs for the NF complex, where the lowest energy singlet state is very close in energy to a spin allowed crystal field band, giving rise to intense vibronic patterns. ... 

The first model implies the rupture of the coordination bonds. This is inconsistent with the inertness of the macrobicyclic complex because its decomposition causes the rupture not only of M-N bonds, but also of C-C and C-H bonds. Therefore, this model predicts a relatively long lifetime of the state for the [Cr(sep)]3+ cation. In fact, the E states for [Cr(en)s] and [Cr(sep)] + cations have very similar lifetimes (of the order of 10 ps) in DMF at 0°C and similar spectral characteristics (both of them show an intense band at 15 151 cm-i and possess a quantitatively similar low-intensity vibronic structure). The macrobicyclic ligand ensures that ligand dissociation will have a large activation barrier, even in metal-centred electronic exited states. Neither the first model nor the second one adequately accounts for the photolytic similarities of [Cr(sep)]3+, [Cr(en)3] + and [Cr(NH3)e] cations. The third model seems the most realistic alternative [159]. 

Acridine in benzene emits the fluorescence with three main vibrational bands. The most intense vibronic band is at 24500 cm . The fluorescence band of acridine in ethanol is shifted to the red by 500 cm compared with that in benzene. In an acidic solution, acridine shows a broad emission band which was assigned to the fluorescence of acridinium cation (6). The peak wavenumber of the band is 20700 cm . ... 

The spectroscopy of the aniline molecule has been extensively studied, 14,15 and the most intense vibronic features have been assigned. The assignments of some of these peaks are indicated in Figure 1. The corresponding aniline(Ar)i spectrum has its origin shifted about 40 cm to the red of the corresponding bare molecule origin. The other (vibronic) peaks are shifted by approximately the same amount. These shifts can be understood in terms of a n... 

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