Spectroscopic investigation of the Ã [sup 1]A[sup ʺ]-X̃ [sup 1]A[sup ʹ] electronic transition of HSiNCO
journal contributionposted on 29.09.2009, 13:52 by Matthew Richard Dover, Corey J. Evans, Colin M. Western
The first spectroscopic observation of the previously unknown species HSiNCO has been reported. HSiNCO was generated by the fragmentation of trimethylsilylisocyanate with a high-voltage discharge source. The 0[sup 0, sub 0] band of the Ã [sup 1]A[sup ʺ]-X̃ [sup 1]A[sup ʹ] transition has been recorded with full rotational resolution using laser-induced fluorescence spectroscopy and ground and excited state rotational and centrifugal distortion constants determined. Ten additional vibrational bands belonging to HSiNCO have also been observed in the laser-induced fluorescence spectrum and have been assigned based on predicted anharmonic vibrational frequencies. Due to the large change in geometry upon excitation, a number of axis-rotation peaks have been observed in the 0 [sup 0, sub 0] band and the axis-rotation angle (θ [sub T]) has been estimated to be 0.6°±0.2°. Dispersed fluorescence spectroscopy has been carried out and ν[sub 8] (the N–C–O out-of-plane bending mode) and a number of overtones of ν[sub 4] (the Si–H wagging mode) have been observed in the ground electronic state.