Infrared Spectra Of CF2=CHD and CF2=CD2: Scaled Quantum-chemical Force Fields And An Equilibrium Structure For 1,1-difluoroethylene

Title:
Infrared Spectra Of CF2=CHD and CF2=CD2: Scaled Quantum-chemical Force Fields And An Equilibrium Structure For 1,1-difluoroethylene
Authors:
McKean, Donald C.; Law, Mark M.; Groner, Peter; Conrad, Andrew R.; Tubergen, Michael J.; Feller, David; Moore, Michael C.; Craig, Norman C.
Abstract:
Infrared (IR) spectra in the gas phase are reported for CF2=CHD and CF2=CD2 in the region 350-4000 cm(-1). Ab initio calculations of an harmonic force-field and anharmonicity constants have been made with an MP2/aug-cc-pVTZ model. These enable a number of Fermi resonances in each species to be analyzed and a complete set of "observed" harmonic frequencies to be derived. The latter are combined with similar data for CF2=CH2 in a scaling of the model harmonic force field to both anharmonic and harmonic frequencies. Inspection of the scale factors reveals minor defects of the model, evident in the out-of-plane wagging modes and in the CF stretch/CF stretch interaction force constant. Fermi resonance treatments involved in all isotopomers studied are compatible with the overall force-field refinement results. The treatment leaves a small anomaly in the C-13 shift on v(1). Improved microwave spectra are reported for five isotopic species, and a semiexperimental equilibrium structure for F2C=CH2 is determined and compared favorably with the structure obtained from new high-level ab initio calculations. Centrifugal distortion constants are predicted for the five isotopic species, and those for F2C=CH2 are compared with values fit to microwave spectra.
Citation:
McKean, Donald C., Mark M. Law, Peter Groner, Andrew R. Conrad, et al. 2010. "Infrared Spectra Of CF2=CHD and CF2=CD2: Scaled Quantum-chemical Force Fields And An Equilibrium Structure For 1,1-difluoroethylene." Journal Of Physical Chemistry A 114(34): 9309-9318.
Publisher:
American Chemical Society
DATE ISSUED:
2010-09
Department:
Chemistry
Type:
article
PUBLISHED VERSION:
10.1021/jp104498n
PERMANENT LINK:
http://hdl.handle.net/11282/309933

Full metadata record

DC FieldValue Language
dc.contributor.authorMcKean, Donald C.en_US
dc.contributor.authorLaw, Mark M.en_US
dc.contributor.authorGroner, Peteren_US
dc.contributor.authorConrad, Andrew R.en_US
dc.contributor.authorTubergen, Michael J.en_US
dc.contributor.authorFeller, Daviden_US
dc.contributor.authorMoore, Michael C.en_US
dc.contributor.authorCraig, Norman C.en_US
dc.date.accessioned2013-12-23T16:21:30Zen
dc.date.available2013-12-23T16:21:30Zen
dc.date.issued2010-09en
dc.identifier.citationMcKean, Donald C., Mark M. Law, Peter Groner, Andrew R. Conrad, et al. 2010. "Infrared Spectra Of CF2=CHD and CF2=CD2: Scaled Quantum-chemical Force Fields And An Equilibrium Structure For 1,1-difluoroethylene." Journal Of Physical Chemistry A 114(34): 9309-9318.en_US
dc.identifier.issn1089-5639en_US
dc.identifier.urihttp://hdl.handle.net/11282/309933en
dc.description.abstractInfrared (IR) spectra in the gas phase are reported for CF2=CHD and CF2=CD2 in the region 350-4000 cm(-1). Ab initio calculations of an harmonic force-field and anharmonicity constants have been made with an MP2/aug-cc-pVTZ model. These enable a number of Fermi resonances in each species to be analyzed and a complete set of "observed" harmonic frequencies to be derived. The latter are combined with similar data for CF2=CH2 in a scaling of the model harmonic force field to both anharmonic and harmonic frequencies. Inspection of the scale factors reveals minor defects of the model, evident in the out-of-plane wagging modes and in the CF stretch/CF stretch interaction force constant. Fermi resonance treatments involved in all isotopomers studied are compatible with the overall force-field refinement results. The treatment leaves a small anomaly in the C-13 shift on v(1). Improved microwave spectra are reported for five isotopic species, and a semiexperimental equilibrium structure for F2C=CH2 is determined and compared favorably with the structure obtained from new high-level ab initio calculations. Centrifugal distortion constants are predicted for the five isotopic species, and those for F2C=CH2 are compared with values fit to microwave spectra.en_US
dc.language.isoen_USen_US
dc.publisherAmerican Chemical Societyen_US
dc.identifier.doi10.1021/jp104498nen
dc.subject.departmentChemistryen_US
dc.titleInfrared Spectra Of CF2=CHD and CF2=CD2: Scaled Quantum-chemical Force Fields And An Equilibrium Structure For 1,1-difluoroethyleneen_US
dc.typearticleen_US
dc.identifier.journalJournal Of Physical Chemistry Aen_US
dc.subject.keywordCorrelated molecular calculationsen_US
dc.subject.keywordPhase electron-diffractionen_US
dc.subject.keywordGaussian-basis setsen_US
dc.subject.keywordVibrational anharmonicityen_US
dc.subject.keywordMicrowave spectraen_US
dc.subject.keywordAb initio calculationsen_US
dc.subject.keywordDifluoroethylenesen_US
dc.subject.keywordButadieneen_US
dc.subject.keywordHydrogenen_US
dc.subject.keywordEthyleneen_US
dc.subject.keywordChemistry, physicalen_US
dc.subject.keywordPhysics, atomic, molecular & chemicalen_US
dc.identifier.volume114en_US
dc.identifier.issue34en_US
dc.identifier.startpage9309en_US
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