Rotational Spectrum of cis-HS3D

In our pursuit of understanding the structure of sulfur chain molecules we have extended our investigations on the rotational spectrum of HSSSH [1, 2] to the partially deuterated species HSSSD. The rotational spectrum of HSSSH was found to be dense, and the carrier of the strongest absorption lines assigned at that time was the cis-conformer of HSSSH, displaying a strong c-type spectrum. Since the non-planar cis-conformation, in which the two hydrogen atoms are attached to end-sulfur-atoms of the bend sulfur chain, exhibits C s symmetry [1, 2], one expects a perpendicular-type spectrum consisting of both cand 6-type transitions with one of them carrying the stronger component of the dipole moment. A similar situation is predicted for cis-HSSSD and has now been found: The assigned rotational spectrum consists of strong c-type and weak b-type transitions, confirming the structure shown in Figure 1. The purpose of this communication is to present a preliminary analysis of the observed cis-HSSSD transitions with a comparison to HSSD [3].