VIBRATIONAL STRUCTURE OF THE A(3)PI(0)-X-1-SIGMA(-3-PI(1)-X-1-SIGMA(+) TRANSITIONS OF GALLIUM MONOCHLORIDE() AND B)

The electronic spectrum of GaCl was excited in a microwave discharge ( 2450 MHz) using natural gallium as well as the single isotopes Ga-69 a nd Ga-71, separately. The resulting emission spectrum, in the near-UV region, consisting of two overlapping transitions A (3) Pi(0) - X-1 Si gma(+) and B (3) Pi(1) - X-1 Sigma(+), was recorded at moderate and hi gh resolutions on a 3.4 m Ebert grating spectrograph. Many new bands w ere observed as the spectrum is cleaner and more extensive when compar ed to the work reported in earlier literature. The analysis was extend ed to include many more vibrational levels of the B (3) Pi(1), A(3) Pi (0), and X-1 Sigma(+) states of GaCl. The head of the heads was observ ed in the Delta v greater than or equal to 1 sequences. From the band- head measurements more accurate vibrational constants have been determ ined for the three electronic states using a simultaneous least-square s fit of all the bands of the two systems of the four isotopic molecul es.