15min:

T. HIRAO, K. TERESZCHUK AND P. F. BERNATH, Department of Chemistry, University of Waterloo, Waterloo, Ontario, CANADA N2L 3G1.

It is known that ZnH has a relatively shallow potential curve in its ground state (D_e~ ~7,660~cm^-1), however, accurate spectral information on the higher vibrational levels in the X ^{2 +} state is not available. In this study, we recorded Fourier transform spectra in 400-500 nm region using a DC discharge inside a tube furnace. A deep blue emission was observed over the granulated zinc heated to 770 K in a slow flow of Ar ( ~5 Torr) with a trace of H₂. So far we identified A ² -X ^{2 +} transitions up to v'=2 and v''=4, as well as the B ^{2 +}- X ^{2 +} 0-4 band. In this B-X band, lines are found to be diffuse around N''=21 and completely dissapear for higher-N''. Based on the potential curve in the ground state, we found that this happens because of rotational predissociation. We also discuss a deperturbation of the A ² and B ^{2 +} states.