dc.creator Miller, Elisa M. en_US dc.creator Sheps, Leonid en_US dc.creator Lu, Yu-Ju en_US dc.creator McCoy, Anne B. en_US dc.creator Lineberger, W. Carl en_US dc.date.accessioned 2011-07-12T17:39:24Z dc.date.available 2011-07-12T17:39:24Z dc.date.issued 2011 en_US dc.identifier 2011-MF-14 en_US dc.identifier.uri http://hdl.handle.net/1811/49660 dc.description Author Institution: JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder; Co 80309; Department of Chemistry, The Ohio State University, Columbus, OH, 43210; JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder; Co 80309 en_US dc.description.abstract We report the photoelectron spectrum of ICN$^{-}$ to probe transitions to the ground state (X $^{1}\Sigma^{+}$) and first 5 excited states ($^{3}\Pi_{2}$, $^{3}\Pi_{1}$, $^{3}\Pi_{0-}$, $^{3}\Pi_{0+}$, and $^{1}\Pi_{1}$) of neutral ICN. We spectroscopically resolve the first 3 excited states and a conical intersection region between the $^{3}\Pi_{0+}$ and $^{1}\Pi_{1}$ states for the first time. The spectra are assigned with the aid of previously published high-level calculations by Morokuma and coauthors . Our assignments are further verified by comparison to the photoelectron spectra of the dihalides I$_{2}^{-}$ and IBr$^{-}$. The poor Franck-Condon overlap between the ground states of the anion and neutral precludes direct observation of the adiabatic electron affinity, EA(ICN). However, through thermochemical cycles involving narrow transitions to excited states, we determine the EA(ICN) to be 1.7$\pm$0.1 eV and the dissociation energy, D$_{0}$(ICN$^{-}$), to be 0.9$\pm$0.1 eV. To our knowledge, the EA(ICN) has not been previously reported in experiment or theory; therefore, this is the first EA(ICN) determination. In addition, we observe at least four spectral peaks with kinetic energies of $\leq$ 5, 45, 70, and 160 meV that are independent of the photon energy over the 2.6 - 4.1 eV energy range. It appears that these peaks are related to autodetachment from excited anions to the ground electronic state of the neutral. We use a combination of previous calculations by Morokuma et al. and two-dimensional SO-MR-CI scans with a fixed CN distance of the anion potential energy surfaces to aid in an autodetachment mechanism. Support from NSF and AFOSR is gratefully acknowledged. en_US dc.language.iso en en_US dc.publisher Ohio State University en_US dc.title PHOTOELECTRON SPECTROSCOPY OF ICN$^{-}$: CHARACTERIZATION OF A CONICAL INTERSECTION IN ICN en_US dc.type Article en_US
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