Out-of-Plane Bending Frequencies in Trimethylene Sulfide from Microwave Intensity Measurements

The first four out-of-plane ring-bending energy separations in trimethylene sulfide[Complex chemical formula]have been determined from microwave intensity measurements on the 000−101, 634−633, and 423−422 rotational transitions in X band. These separations are 0, 141, 15, and 85 cm−1 for the 0–1, 1–2, 2–3, and 3–4 transitions, respectively, indicating a bent configuration for the ring. The uncertainty in these numbers is about ±3 cm−1.