For the first time the millimeter-wave spectra of the trans-35 ClHC= CHF and trans-37 ClHC= CHF isotopomers have been observed in natural abundance. Many ΔJ= 0,±1 ΔK− 1=+ 1 transitions for 35 ClHC= CHF and ΔJ= 0 ΔK− 1=+ 1 transitions for 37 ClHC= CHF have been detected and assigned. This allowed us to accurately determine the vibrational ground- staterotational constants, quartic and some sextic centrifugal distortion constants, and ...
