ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
New electronic transitions of the CaNC and SrNC free radicals have been identified in the near ultraviolet. For CaNC one new system, labeled the D˜–X˜ transition, was observed in the 31 500–33 400 cm−1 region. Two new transitions were found for SrNC, the D˜–X˜ and E˜–X˜ systems spanning 29 100–31 000 and 32 750–34 000 cm−1, respectively. Jet-cooled laser excitation spectra yield complex vibrational structure, much of which is attributed to excitation of the bending vibration. This has been used to infer that the molecule adopts a nonlinear equilibrium geometry in the upper electronic state in all three band systems, in contrast to the linear ground electronic state. This structural change is accounted for by the increased diffuseness of the unpaired electron in the excited states, which favors deviation from linearity. All three new excited states are assigned 2A′ symmetry and correlate with 2Σ+ states in the linear molecule limit. Tentative estimates for the barriers to linearity in the D˜ 2A′ states of CaNC and SrNC have been determined as ∼700 and ∼1050 cm−1, respectively. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1319344
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