High-resolution spectroscopy of [H,C,N]⁺: I. Rotationally resolved vibrational bands of HCN⁺ and HNC^.

ABSTRACT: Rovibrational spectra of the open-shell linear cations HCN⁺ (X̃²Π) and HNC⁺ (X̃²Σ⁺) are measured with leak-out spectroscopy in cryogenic 22-pole ion traps. The fundamental ν₁ C-H stretching vibration of HCN⁺ is found at 3056.3412(1) cm^-1 and the lower energy Renner-Teller (RT) component (Σ) of the ν₁ + ν₂ combination band is found at 3340.8480(2) cm^-1. The resulting effective RT vibrational frequency of ≈300 cm^-1 inferred from the comparison of these two bands indicates a large Renner-Teller splitting for HCN⁺. For HNC⁺, the ν₁ N-H stretching vibration is found at 3407.9136(4) cm^-1, much h

SUBMITTER: Schmid PC 

PROVIDER: S-EPMC12851410 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature