PNNL

Abstract

The spectrum of the nu10 band of diborane, arising from the ring puckering vibration, has been obtained with a spectral resolution of 0.0015 cm-1 in the region 275 to 400 cm-1. The spectrum of a sample enriched in 10B was recorded as well as one with naturally abundunt boron, i.e., 64% 11B2H6, 32% 10BH6 and 4% 10B2H6. This mode is the lowest vibrational level of the molecule and is unperturbed, allowing a complete assignment of not only the fundamental bands but also the 2v10 - v10 hot bands of all three boron isotopomers. The intensities of several hundred lines of the fundamental and hot bands of all isotopomers have been measured and vibrational transitition moments have been obtained. Finally, it has been shown that the harmonic approximation does not apply for v10.