title: Rotational spectrum and structure of the carbonyl sulfide-trifluoromethane weakly bound dimer.
abstract: Pure rotational spectra of five isotopomers of the 1:1 weakly bound complex formed between carbonyl sulfide and trifluoromethane (TFM) have been measured using Fourier transform microwave spectroscopy. The experimental rotational constants and dipole moment components are consistent with a structure of C(s) symmetry in which the dipole moment vectors of OCS and HCF(3) are aligned antiparallel and at an angle of about 40 degrees and with a center of mass separation of 3.965(26) A. The derived H...O distance is 2.90(5) A, which is up to 0.6 A longer than is seen in other similar TFM complexes exhibiting C-H...O interactions. Ab initio calculations at the MP2/6-311++G(2d,2p) level give a structure with rotational constants that are in reasonable agreement with those of the normal isotopic species.
authors.affiliation: Department of Chemistry, Eastern Illinois University, 600 Lincoln Avenue, Charleston, Illinois 61920, USA.
authors.forename: Michal M
authors.initials: MM
authors.lastname: Serafin
authors.forename: Sean A
authors.initials: SA
authors.lastname: Peebles
mesh_terms: D005617:Chlorofluorocarbons, Methane / Q000737:chemistry*; D006860:Hydrogen Bonding; D012399:Rotation; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013461:Sulfur Oxides / Q000737:chemistry*
chemical_list: D005617:Chlorofluorocarbons, Methane; D013461:Sulfur Oxides; C010063:carbonyl sulfide; C009554:fluoroform