Analysis of the rotational structure in the high-resolution infrared spectra of cis,cis- and trans,trans-1,4-difluorobutadiene-1-d1 and trans,trans-1,4-difluorobutadiene-1,4-d2

Craig, Norman C.; Chen, Yihui; Lu, Yan; Neese, Christopher F.; Nemchick, Deacon J.; Blake, Thomas A.

doi:10.1016/j.jms.2013.03.006

Cited by 2 publications

(5 citation statements)

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“…A reevaluation of the analysis of the rotational structure in the high-resolution IR spectrum of ccDFBD-1-d 1 suggests that the uncertainties in B 0 and C 0 are about twice as large as reported. 20 Furthermore, if we calculate the GS inertial defect from the MP2(FC)/VTZ force field, we can conclude that it should be almost identical for the parent and for the 1-d 1 species, thereby confirming the inaccuracy of at least one GS rotational constant for the d 1 species.…”

Section: Semiexperimental Equilibrium Structuresmentioning

confidence: 74%

“…The harmonic values are higher by about 2.1(1) kJ mol −1 . Thus, ZPVE decreases the tt−cc and ct−cc energy separations by substantial 146 (20) and 79(15) cm −1 , respectively, taking the average of the computed values. This yields, ΔE 0 = 470 (21) and 260(16) cm −1 for the relative energies, respectively.…”

Section: Relative Energies Of the Isomersmentioning

confidence: 87%

“…For ttDFBD GS rotational constants were also determined experimentally for the 1,4-d 2 species. 20 Results for these nonpolar isomers of DFBD came from the analysis of highresolution infrared (IR) spectra.…”

Section: Introductionmentioning

confidence: 99%

“…Presumably, GS rotational constants for the singly substituted 18 F species can also be predicted with good accuracy. GS rotational constants have been determined experimentally for the parent species, the 2 - d 1 species, and the 1 - d 1 species of the cc and tt isomers of DFBD. For ttDFBD GS rotational constants were also determined experimentally for the 1 , 4 - d 2 species .…”

Section: Introductionmentioning

confidence: 99%

“…GS rotational constants have been determined experimentally for the parent species, the 2 - d 1 species, and the 1 - d 1 species of the cc and tt isomers of DFBD. For ttDFBD GS rotational constants were also determined experimentally for the 1 , 4 - d 2 species . Results for these nonpolar isomers of DFBD came from the analysis of high-resolution infrared (IR) spectra.…”

Section: Introductionmentioning

confidence: 99%

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Semiexperimental Equilibrium Structures for cis,cis- and trans,trans-1,4-Difluorobutadiene by the Mixed Estimation Method and Definitive Relative Energies of the Isomers

et al. 2013

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Equilibrium molecular structures accurate to 0.001 Å and 0.2° have been determined for cis,cis- and trans,trans-1,4-difluorobutadiene by the semiexperimental mixed estimation method. In this method, structures are fitted concurrently to equilibrium rotational constants and bond parameters obtained from an intermediate level of electronic structure theory. The effect of fluorine substitution on the carbon backbone of butadiene is surprisingly small. Definitive energy differences for the ground states were computed, employing the focal-point analysis (FPA) technique, between the trans,trans and cis,cis isomers (ΔH°0 = 5.6(3) kJ mol(-1)) and the cis,trans and cis,cis isomers (ΔH°0 = 3.2(2) kJ mol(-1)) of 1,4-difluorobutadiene. These differences confirm the exceptional relationship that the trans,trans isomer has the highest energy and the cis,cis isomer the lowest energy, endorsing what was reported earlier on the basis of experimental observations in benzene solution.

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Section: Semiexperimental Equilibrium Structuresmentioning

confidence: 74%

Section: Relative Energies Of the Isomersmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Semiexperimental Equilibrium Structures for cis,cis- and trans,trans-1,4-Difluorobutadiene by the Mixed Estimation Method and Definitive Relative Energies of the Isomers

et al. 2013

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Weak Acidity of Vinyl CH Bonds Enhanced by Halogen Substitution

Craig

Matlin

2014

J. Org. Chem.

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As shown by the rates of proton-deuteron exchange in ethylenes with halogen substituents, the weak acidity of vinyl CH bonds is enhanced by halogen substitution. Relative rates of exchange in basic deuterium oxide reflect the relative acidities. Substitution in the α position has the strongest effect. Less electronegative halogens such as bromine increase the acidity more than does fluorine. The vinyl CH acid strengths correlate closely with the energies of deprotonation of isolated molecules into isolated anions, as computed with the MP2/cc-pVQZ model. The smaller deprotonation energies are associated with the stronger acids. Atomic charges from a natural bond order analysis done with the MP2/aug-cc-pVQZ model show that the negative charge becomes more dispersed in the anions of the stronger acids. Results are given for 13 haloethylenes and for 6 halogen-substituted butadienes, cyclopropenes, and a cyclobutene.

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Analysis of the rotational structure in the high-resolution infrared spectra of cis,cis- and trans,trans-1,4-difluorobutadiene-1-d1 and trans,trans-1,4-difluorobutadiene-1,4-d2

Cited by 2 publications

References 16 publications

Semiexperimental Equilibrium Structures for cis,cis- and trans,trans-1,4-Difluorobutadiene by the Mixed Estimation Method and Definitive Relative Energies of the Isomers

Semiexperimental Equilibrium Structures for cis,cis- and trans,trans-1,4-Difluorobutadiene by the Mixed Estimation Method and Definitive Relative Energies of the Isomers

Weak Acidity of Vinyl CH Bonds Enhanced by Halogen Substitution

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