title: Conformational Flexibility of Limonene Oxide Studied By Microwave Spectroscopy.
abstract: Monoterpenoids are biogenic volatile organic compounds that play a major role in atmospheric chemistry by participating in the formation of aerosols. In this work, the monoterpenoid (R)-(+)-limonene oxide (C10H16O) was characterized in the gas phase by Fourier-transform microwave spectroscopy in a supersonic jet. Five conformers of limonene oxide, four equatorial and one axial considering the configuration of the isopropenyl group, were unambiguously identified from analysis of the rotational spectrum. The observed conformers include cis and trans forms, which are stabilized by a subtle balance of hydrogen bonds, dispersive interactions, and steric effects. Estimated conformational relative abundances surprisingly reveal that the abundance of the axial conformer is similar to that of some of the equatorial conformers. In addition, the potential energy surface was extensively explored by using density functional theory and ab initio methods.
authors.affiliation: Department of Chemistry, King's College London, London, United Kingdom.
authors.forename: Donatella
authors.initials: D
authors.lastname: Loru
authors.affiliation: University of Jaen, Department of Physical and Analytical Chemistry, Campus Las Lagunillas, E-23071, Jaen, Spain.|PhLAM, UMR8523 CNRS-, Université Lille 1, Bâtiment P5, F-59655, Villeneuve D'Ascq Cedex, France.
authors.forename: María Mar
authors.identifier: http://orcid.org/0000-0002-2286-7727
authors.initials: MM
authors.lastname: Quesada-Moreno
authors.affiliation: PhLAM, UMR8523 CNRS-, Université Lille 1, Bâtiment P5, F-59655, Villeneuve D'Ascq Cedex, France.
authors.forename: Juan Ramón
authors.identifier: http://orcid.org/0000-0001-9952-8435
authors.initials: JR
authors.lastname: Avilés-Moreno
authors.affiliation: Department of Chemistry, King's College London, London, United Kingdom.
authors.forename: Natasha
authors.initials: N
authors.lastname: Jarman
authors.affiliation: PhLAM, UMR8523 CNRS-, Université Lille 1, Bâtiment P5, F-59655, Villeneuve D'Ascq Cedex, France.
authors.forename: Thérèse R
authors.initials: TR
authors.lastname: Huet
authors.affiliation: University of Jaen, Department of Physical and Analytical Chemistry, Campus Las Lagunillas, E-23071, Jaen, Spain.
authors.forename: Juan Jesús
authors.identifier: http://orcid.org/0000-0003-1895-3806
authors.initials: JJ
authors.lastname: López-González
authors.affiliation: Department of Chemistry, King's College London, London, United Kingdom.
authors.forename: M Eugenia
authors.initials: ME
authors.lastname: Sanz
mesh_terms: D000081005:Cyclohexane Monoterpenes; D008872:Microwaves; D008968:Molecular Conformation; D015394:Molecular Structure; D039821:Monoterpenes / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D000081005:Cyclohexane Monoterpenes; D039821:Monoterpenes; C028940:limonene-1,2-epoxide
keywords: ab initio calculations; atmospheric chemistry; conformation analysis; rotational spectroscopy; terpenoids