Vibrational and Electronic Spectroscopy of 2-Cyanoindene Cations.

ABSTRACT: 2-Cyanoindene is one of the few specific aromatic or polycyclic aromatic hydrocarbon (PAH) molecules positively identified in Taurus molecular cloud-1 (TMC-1), a cold, dense molecular cloud that is considered the nearest star-forming region to Earth. We report cryogenic mid-infrared (550-3200 cm^-1) and visible (16,500-20,000 cm^-1, over the D ₂ ← D ₀ electronic transition) spectra of 2-cyanoindene radical cations (2CNI⁺), measured using messenger tagging (He and Ne) photodissociation spectroscopy. The infrared spectra reveal the prominence of anharmonic couplings, particularly over the fingerprint region. There is a strong CN-stretching mode at 2177 ± 1 cm^-1 (4.593 μm), which may contribute to a broad plateau of

SUBMITTER: Douglas-Walker TE 

PROVIDER: S-EPMC11744931 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature