Rotational analysis of bands in the high-resolution infrared spectra of cis,cis- and trans,trans-1,4-difluorobutadiene-2-d1

► Synthesis of cis,cis- and trans,trans-1,4-difluorobutadiene-2-d1. ► Analysis of rotational structure in high-resolution IR spectra of these species. ► Ground state rotational constants for use in a semiexperimental equilibrium structure.