Knowledge Bank

The (3000), (4000) and (5000) stretching overtone bands of silane have been recorded on a BOHEM Fourier transfer spectrometer equipped by a multipass absorption cell, which had an effective length of up to 100 meters and was capable of holding the sample pressure almost constant over two days continuous scan. A symmetric top rotational structure, similar to that observed in the (3000) band of germane[1], was clearly demonstrated, indicating that the upper states were very near the local mode limit. The band origins agree well with the model vibrational calculation[2]. In addition, some interesting intensity anomalies and perturbations were found in these spectra and will be reported here