of charge density on the methylene carbon and an increase in charge denslty on the phenyl ring. A large reorganization of charge in the excited state could result in a greatly reduced stabilization of the excited state relative to the ground state and a correspondingly large blue shift in the solution absorption feature relative to the gas-phase spectrum.
SummaryThe photodetachment spectra of the phenylnitrene, anilide, and benzyl anions have been presented. Theoretical photodetachment cross sections for each species were calculated and fit to the experimental data. The agreement between the experimental and theoretical cross sections are good and lead to accurate assignments of the photodetachment onsets in the three spectra. From the phenylnitrene spectrum, the splittings between the ground triplet state aqd the first two singlet states of the nitrene have been determined. The electron affinities of the phenylnitrene, anilide, and benzyl neutrals have been determined. These electron affinities, in conjunction with literature values for the proton affinities of these species, have led to the determination of C-H and N-H bond strengths in toluene, aniline, the anilide anion, and the anilide radical.The photodetachment spectra presented also show structures indicative of transitions to excited states of the respective anions.These features were assigned as B2 -A, and B, -B2 transitions in the anions. A large blue shift was observed in the lowest-energy excited-state transition in the benzyl anion solution absorption spectrum, relative to the same feature in the photodetachment spectrum.Ag colloids with adsorbed CN-complexes, pyridine, and HSO,-/SO,*-ions are prepared and characterized by their elastic scattering spectra, extinction spectra, and particle size distributions. Enhanced Raman spectra from these colloids are measured as a function of incident laser wavelength over the 423-676.4-nm range. The maximum in the excitation profile for the Raman scattering shifted to a longer wavelength than that for the elastic scattering and extinction profiles. Furthermore, the Raman excitation profile peaked at a longer wavelength than that predicted by the electromagnetic calculations for the field at the tips of and surface-averaged over isolated spheres of various radii. The effect of colloid aggregation on the SERS intensity of CN-complexes adsorbed on the Ag colloids is discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations –citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.