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.     

What is so mysterious about the electronic states of SCI?

The 15 lowest lying doublet electronic states of the molecule SCI have been investigated theoretically at a high level of correlation treatment (MRCI). For the ground state (X ²II), spectroscopic constants were obtained from a set of eight vibrational intervals. This result extends our knowledge about this state beyond the experimentally known data that presently were derived from only two bands. Spin-orbit constants, transition probabilities and radiative lifetimes complement its spectroscopic characterization. For the excited electronic states, a global view of the doublet states is presented that can help us understand the scarcity of experimental data on electronic transitions for this system and also the difficulty of assigning the only two transitions so far recorded. Most of these states are repulsive, and for the few high lying bound ones, of Rydberg character, avoided crossings restrict the number of accessible vibrational states. Crossing by repulsive states and predissociation is also a factor that can prevent further emissions. Two new bound excited states, ²δ and ²Σ, predicted in this study, are of direct relevance to an interpretation of the limited experimental data available on electronic transitions.