Electronic transition moment of the A 2Π r–X 2Σ + system of TiN

Abstract

The A 2Π r–X 2Σ + transition of TiN was observed by the dispersed laser induced fluorescence (DLIF) spectroscopy. The relative intensities of the DLIF spectra were analyzed to determine the dependence of the electronic transition moment, R e( r), on the internuclear distance, r, as R e( r)∝{1−0.281(26) r} (1.380 Å≤ r≤1.823 Å). This r-dependence was analyzed simultaneously with the reported values of the spin–orbit constants for A 2Π r and the hyperfine-coupling constants for X 2Σ + to evaluate the ionic character of the TiN bond, the 4s atomic character in the 9σ orbital of X 2Σ +, and the 4p atomic character in the 4π orbital of A 2Π r. These characters were confirmed to be in accordance with the reported theoretical prediction. A strong r-dependence was indicated for the 3d–4p mixing in the A 2Π r state due to the configuration mixing of the Ti(3d 4) and Ti(3d 34p) states at a large internuclear distance.