Electrostatic hexapole state-selection of the asymmetric-top molecule propylene oxide: Rotational and orientational distributions

Rotational state-selection and alignment of chiral molecules by electrostatic hexapoles

“…Propylene oxide is an asymmetric-top molecule with a Ray's parameter of -0.87 and a permanent dipole moment of 2.2 D. Its focusing curve was characterized as a pure beam, seeded in He (20 % in propylene oxide) and seeded in Ar (20 % in propylene oxide. Details of the experimental apparatus and of trajectory simulations are given in references [9,10]. In Figure 2 (left panel) we report, as an example, the experimental focusing curve of pure propylene oxide and the simulated ones by assuming adiabatic and non-adiabatic transitions in case of avoided curve crossing.…”

“…They were initially applied to linear and symmetric-top molecules, while more recently they have been successfully applied to molecules of higher complexity such as the chiral molecules propylene oxide 9,10 (for a characterization of the reaction pathways of propylene oxide see reference [11]) and 2-bromobutane 12 (see also reference [13]). Hexapolar technique has been also employed for the first time in the selection of conformers of 2-butanol 14 .…”

Conformer Selection by Electrostatic Hexapoles: A Theoretical Study on 1-Chloroethanol and 2-Chloroethanol

“…Such a behavior is commonly respected in case of small molecules with weak electric fields, and it is usually treated in the ansatz of first order perturbation. To incorporate the complete Stark effect, we applied a more rigorous approach based on the diagonalization of the full Hamiltonian matrices of Stark interaction, where the dependence on the electric field is explicit (see [10]). This approach was necessary for the electric field strength and molecules we considered in this work.…”

“…This firstly implies that molecules must possess an appreciable permanent dipole moment, commonly higher than 0.6 D. Hexapoles have been employed to select rotational states in linear and symmetric-top molecules [3][4][5][6][7]. In the 21st century, the hexapolar technique has been extended to asymmetric-top molecules, initially to CH 2 F 2 [8] and later to molecules of increasing complexity such as propylene oxide [9,10] and 2butanol [11], where the increasing molecular weight made the rotational state manifold much denser and more congested than that of the previously investigated molecules, thus making it impossible to select a single rotational state. Nevertheless, the hexapole turned out to be an excellent cluster selector since the formation of clusters normally leads to the cancellation of the dipole moment [12].…”

A Quantum Chemical Approach for the Characterization of the Interaction Potential of Propylene Oxide with Rare-Gas Atoms (He, Ne, Ar)

“…Its commercial availability is also remarkable for both the racemic mixture and the two enantiomers. It has been largely studied both experimentally, for example by synchrotron radiation [3] and molecular beams [4,5], and from a computational point of view. For this latter aspect, see for example the representation of the potential energy surfaces of propylene oxide with helium [6,7] and the study of the structural isomers manifold of C3H6O [8].…”