The rotational spectrum of cyclohexyl formate, chemically prepared within a supersonic expansion

The pulsed supersonic jet expansion microwave spectra of the parent and of the CD=O monodeuterated species of cyclohexylformate have been measured in the 6.5–18 GHz range. The samples have been obtained by direct esterification of HCOOH (or DCOOH) with cyclohexyl alcohol during a supersonic expansion in a microwave cavity. Most of the observed transitions are split into two component lines, due to the tunnelling motion connecting two equivalent gauche forms. The tunnelling barrier has been determined to be B2 = 267 (10) cm−1. Structural information has been obtained from the 6 available rotational constants.