Microwave Spectrum, Structure, and Dipole Moment of Formyl Fluoride

The microwave spectra of several isotopic species of formyl fluoride have been investigated in the region 11–46 kMc. Both parallel and perpendicular transitions have been assigned. The effective rotational constants for HC12OF are (Mc) a=91153.6, b=11760.0, c=10396.8; for HC13OF, a=88475.3, b=11755.2, c=10357.3; for DC12OF, a=65090.1, b=11761.7, c=9941.7. From these constants the structural parameters are calculated to be rCF=1.341 A, rCO=1.183 A, rCH=1.100 A, ≰ FCO=122.7°, ≰ HCF≈108°, ≰ HCO≈129°. Measurements of the Stark effect lead to a value of 2.02±0.02 debyes for the dipole moment.