Christopher R. Brazier

Studies of copper monofluoride in the b3Π state by microwave-optical double resonance and intermodulated fluorescence

Abstract The optical spectrum of copper monofluoride in the yellow has been studied at sub-Doppler resolution to obtain information on the nuclear hyperfine interactions for both 63Cu and 19F nuclei for the upper state (b3Π). The experimental techniques employed were intermodulated fluorescence and microwave-optical double resonance, the electronic transition being excited with a tunable dye laser. The data obtained were fitted together with earlier Doppler-limited measurements to an effective Hamiltonian and values were determined for most of the molecular parameters involved. The b3Π state of copper monofluoride is heavily perturbed by nearby electronic states and it is noteworthy that the effective Hamiltonian can reproduce the observations to within experimental error. Generally speaking, the Cu and F hyperfine parameters are consistent with an ionic description of the b[su3Π state, arising from the configuration Cu+ (3d9 4s1) F− (2p6). However, some anomalies arise. In particular, the parity-dependent hyperfine parameter, d, for the 63Cu nuclei is determined to be negative, contrary to expectation.

Rotational and hyperfine structure in the yellow system of CuF

Abstract Previous spectroscopic studies of copper monofluoride have suggested that the excited electronic state involved in the yellow system is either 3 Σ − or a ( 1 Π, 1 Σ) “ p -complex”. A Doppler-limited (HWHM ⋍ 0.4 GHz), laser-induced fluorescence study of the (0, 0) band of the 63 Cu 19 F isotopic species was performed in order to make a more definite assignment of the upper state. As a result of increased resolution, many of the rotational lines appear as partially resolved quartets resulting from the 63 Cu ( I = 3 2 ) nuclear hyperfine splitting. It was not possible on the evidence available to decide between the alternative assignments for the upper state. Assuming a 3 Σ − state, 200 features were assigned, measured, and fitted by a least-squares procedure to determine values for the parameters (cm −1 ) of CuF in the excited state: T 0 = 17 574.9663(12), λ 0 = − 27.7149(11), λ D 0 = 0.001161(1), B 0 = 0.375035(2), 10 6 D 0 = 0.510(1), γ 0 = 0.01074(6), b F ( 63 Cu ) = 0.032(2) , c( 63 Cu ) = −0.039(7) . The 63 Cu hyperfine parameters are interpreted in terms of possible electronic models of CuF in the A state.

Nuclear hyperfine splittings for copper monofluoride in the a3Σ+ state

Abstract Lines in the (0, 0) band of the a 3 Σ + - X 1 Σ + system of CuF have been recorded at Doppler-limited resolution by laser-induced fluorescence. Nuclear hyperfine structure associated with the Cu nucleus is clearly resolved in many rotational lines. The features have been measured and used to determine molecular parameters for 63 CuF in the a 3 Σ + state. The implications of the hyperfine parameters for the electronic wavefunction are discussed and are shown to be consistent with recent theoretical calculations.