A study on a new 2Δ Rydberg state of SF by resonance-enhanced multiphoton ionization spectroscopy

The (2 + 1) resonance-enhanced multiphoton ionization (REMPI) spectra of SF radicals have been recorded in the single-photon wavelength region of 271-286 nm for the first time. Four regular vibrational bands were observed and assigned as the transition by two-photon from the ground state to a (2)Delta Rydberg state. The (2)Delta Rydberg state arises from one-electron excitation from the 3 pi orbital of SF ground state to a 4p sigma Rydberg orbital, which converging to the first excited ionic state ((1)Delta). The term value T-e, spin-orbit coupling constant A, vibrational frequency and rotational constants for the (2)Delta Rydberg state are determined. (c) 2006 Elsevier B.V. All rights reserved.