High-resolution spectroscopy of [H,C,N]⁺: III. Infrared A²Σ⁺ ← X²Π electronic transition of HCN^.

ABSTRACT: The òΣ⁺ ← X̃²Π electronic transition of the fundamental HCN⁺ ion is reported. The spectrum exhibits a rotational, fine, and hyperfine structure that provides insights into the geometries and wavefunctions of the òΣ⁺ and X̃²Π states. The extracted spectroscopic constants for the à state include (in cm^-1) T_e = 3238.8224(2), B = 1.39568(3), D = 2.27(9) × 10^-5, γ = -0.07332(7), γ_D = 1.87(3) × 10^-4, and the Fermi contact hyperfine constant for the HCN⁺ nitrogen atom b_F = 0.0059(1). Based on this value, the òΣ_1/2⁺ state electronic wavefunction is estimated to have 11.

SUBMITTER: Marlton SJP 

PROVIDER: S-EPMC12885111 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature