Transition metal monophosphides: electronic spectra of TiP, VP and CrP

Titanium, vanadium and chromium monophosphide molecules have been produced in a laser vaporization molecular beam source using metal rods and phosphine. Laser-induced fluorescence spectra at medium (0.1 cm−1) resolution have been recorded from 440 to 740 nm and dispersed fluorescence spectral data have been collected from all strongly emitting states. The most prominent electronic TiP system is attributed to a B2Σ+–X2Σ+ transition with origin near 706.6 nm. In the CrP spectrum the principal bands belong to the 673 nm B4Σ−–X4Σ− system. The ground state vibrational intervals found for TiP, VP and CrP are 521.5, 481 and 406 cm−1, respectively. Vibrational spacings in the various upper states are smaller.