Molecular Structure of Cyclopropyl Chloride

The pure rotational microwave spectra of seven isotopic species of cyclopropyl chloride have been examined and rotational constants assigned. The data are sufficient for a complete structure determination by the substitution method. The bond distances and bond angles obtained are r(C1C2)=1.513 Å, r(C2C3)=1.515 Å, r(CCl)=1.740 Å, average r(CH)=1.08 Å, ∠CCCl=118.7°, ∠ClCH=115.8°, and ∠HCH=116.2°. The quadrupole coupling constants of C3H5Cl35 in the principal inertial axis system are χaa=—56.64 Mc/sec, χbb=36.72 Mc/sec, and χcc=19.92 Mc/sec. These values are consistent with χzz=—71.4 Mc/sec, and ηbond=0.029 if the z axis and the CCl internuclear line are assumed to coincide, and with χzz=—73.5 Mc/sec if the charge distribution near the chlorine nucleus is assumed to be cylindrically symmetric.