FOURIER-TRANSFORM EMISSION-SPECTROSCOPY OF SCH AND SCD - THE NEW SINGLET ELECTRONIC STATES A(1)DELTA, D-1-PI, E-1-DELTA, AND F-1-SIGMA(-)

The emission spectra of ScH and ScD have been investigated in the near infrared and visible using a Fourier transform spectrometer. The mole cules were excited in a scandium hollow cathode lamp operated with neo n gas and a trace of hydrogen or deuterium. Apart from the X-1 Sigma(), B-1 Pi, C-1 Sigma(+), and G(1) Pi states reported previously [R. S. Ram and P. F. Bernath, J. Chem. Phys. 105, 2668-2674 (1996)], four ad ditional new singlet electronic states A(1) Delta, D-1 Pi, E-1 Delta, and F-1 Sigma(-) have been identified below 21 000 cm(-1). The rotatio nal analysis of several vibrational bands of the D-1 Pi-X-1 Sigma(+), D-1 Pi-A(1) Delta, E-1 Delta-B-1 Pi, E-1 Delta-A(1) Delta, and F-1 Sig ma-B-1 Pi transitions has been carried out and spectroscopic consiants have been determined. The E-1 Delta state of ScH was not located beca use of the very weak intensity of the E-1 Delta-B-1 Pi and E-1 Delta-A (1) Delta transitions. (C) 1997 Academic Press.