Laser induced emission spectra of polyyne molecules C 2 nH 2 ( n = 5–8)

Abstract

Listen

Translate article

New optical emission spectra of linear carbon molecules, polyynes C 2 n H 2 ( n = 5–8), were observed upon UV-laser excitation of the 0–0 band of the dipole-allowed transition, 1 Σ u + ← X 1 Σ g + , of size-separated polyyne molecules in hexane. The emission spectra of C 10H 2 showed distinct peaks at 436 and 480 nm with a separation of ∼2100 cm −1 for a stretching vibration of the sp-carbon chain. Weak absorption features were also recorded in near-UV regions in shorter wavelengths to compare with the emission spectra. The spectral features in the emission were assigned to the vibronic bands of the forbidden electronic transition, 1 Δ u → X 1 Σ g + .