High resolution FTIR study of the first GeH stretching overtone band of (H3GeD)-Ge-70

The IR spectrum of monoisotopic (H3GeD)-Ge-70 has been recorded in the region of the first GeH stretching overtone near 4200 cm(-1). Three bands have been observed and assigned in the local mode model to (200A(1)) 4154.139 cm(-1), (200E) 4154.366 cm(-1), and (110E) 4223.07 cm(-1). The low-K sublevels of the (200A(1)/E) states are unperturbed. The analysis of the rotational structure, sigma(fit) = 4.3 x 10(-4) cm(-1), reveals closeness to local mode behavior although this is less pronounced than for the (300A(1)/E) levels. Perturbations by unknown dark states affect both the (110E) level and the (210E, 1) level at 6265.56 cm(-1) that was also analyzed, and Coriolis effects were found to be present here. (C) 1997 Academic Press.