Barrier Studies in the Halopropenes. I. The Microwave Spectrum, Barrier to Internal Rotation, Quadrupole Coupling Constants, and Microwave Doublehyphen;Resonance Spectra of 2hyphen;Chloropropene

摘要

The microwave spectra of CH3C35Cl:CH2and CH3C37Cl:CH2have been observed in the ground and first excited torsional states. The groundhyphen;state rotational constants of CH3C35Cl:CH2areA=9272.79plusmn;0.10 Mc/sec,B=4983.84plusmn;0.10 Mc/sec, andC=3304.39plusmn;0.10 Mc/sec. The groundhyphen;state rotational constants for CH3C37Cl:CH2areA=9272.31plusmn;0.10 Mc/sec,B=4850.48plusmn;0.10 Mc/sec, andC=3245.11plusmn;0.10 Mc/sec. The quadrupole coupling constants along the appropriate principal inertial axes in the ground torsional state of CH3C35Cl:CH2are khgr;aa=minus;68.15plusmn;0.10 Mc/sec, khgr;bb=37.11plusmn;0.10 Mc/sec, and khgr;cc=31.04plusmn;0.10 Mc/sec. The quadrupole coupling constants for CH3C35Cl:CH2in the excited torsional state were within the experimental error of the corresponding groundhyphen;state values. The quadrupole coupling constants in CH3C37Cl:CH2are khgr;aa=minus;53.80plusmn;0.10 Mc/sec, khgr;bb=29.30plusmn;0.10 Mc/sec, and khgr;cc=24.50plusmn;0.10 Mc/sec. Analysis of the first excitedhyphen;torsionalhyphen;state rotational spectrum yielded a barrier to the internal rotation of the methyl group of 2671plusmn;20 cal/mole.Microwave doublehyphen;resonance experiments were used to provide a positive confirmation for the assignments of the 000rarr;101and 101rarr;202transitions in CH3C35Cl:CH2as well as exhibiting some interesting features in the energy levels involved in the transitions. Two types of experiments were performed. The first experiments involved irradiating the quadrupole components in the 000rarr;101transition while observing the 101rarr;202transition. The second set of experiments involved irradiating one of the quadrupole components in the 000rarr;101transition and using a second klystron to observe the entire 000rarr;101triplet.