Rotational spectrum of propylene oxide-neon

The free jet millimetre-wave absorption spectrum of the propylene oxide-Ne complex is reported for both the ²⁰Ne and ²²Ne isotopomers. The Ne atom lies on the same side as the methyl group (syn conformer) with respect to the plane of the COC ring. From the D_J centrifugal distortion constant the dissociation energy has been estimated to be about 1.1 kJ mol^?1.     

Rotational spectrum,dynamics and bond energy of 2,5-dihydrofuran—krypton van der Waals complex

The equilibrium conformation, dynamics and dissociation energy of the weakly bonded 2,5-dihydrofuran-Kr complex have been deduced from its free jet millimetre-wave spectrum. The equilibrium distance of Kr with respect to the centre of mass of the molecule is 3.61 Å, with Kr tilted 12.8° from the perpendicular to the centre of mass of the ring towards the oxygen atom. The dissociation energy is estimated from the centrifugal distortion constant D_J to be about 3.5kJ mol^?1.