High-resolution infrared spectra of the two nonpolar isomers of 1,4-difluorobutadiene

Craig, Norman C.; Moore, Michael C.; Neese, Christopher F.; Oertel, D.; Pedraza, L.J.; Masiello, Tony

doi:10.1016/j.jms.2009.01.003

Cited by 3 publications

(6 citation statements)

References 13 publications

(24 reference statements)

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“…Ground-state rotational constants for the parent and deuterated species of cis,cis-and trans,trans-1,4-difluorobutadiene are known from high-resolution IR spectroscopy. Thanks to ab initio calculations and subsequent scaling corrections, it was possible to predict the ground-state rotational constants of the 13 C and 18 F species with useful accuracy. Corrections for vibration−rotation interaction and electronic effects have given semiexperimental equilibrium rotational constants.…”

Section: Discussionmentioning

confidence: 99%

“…So far, the description how to predict reliable GS rotational constants of ctCFBD, a case where they are experimentally accessible and tests are possible, exemplifies the method used for the cc-and ttDFBD isotopologues. We presume that using this method to predict the GS rotational constants of singly substituted 18 F species is equally good. This test was repeated for several similar molecules, the favorable results are given in Table S1 of the Supporting Information.…”

Section: Prediction Of Rotational Constantsmentioning

confidence: 99%

“…In addition, the utility of this method was confirmed with the 13 C 1 isotopologues of cis-and transhexatriene. 35 Theoretical GS rotational constants were found for the 13 C and 18 F isotopologues of the cc and tt isomers of DFBD from equilibrium rotational constants and alpha/2 sums predicted with the MP2(FC)/VTZ model and the scaling method described in the first paragraph of this section. These GS rotational constants are listed in Table 2.…”

Section: Prediction Of Rotational Constantsmentioning

confidence: 99%

“…This fit was satisfactory, and the parameters, although not very precise, were found to be in good agreement with the r e BO values, as seen in Table 4. Furthermore, the rotational constants of the 13 C species and of the hypothetical 18 F species were calculated from this fitted structure and were compared to their predicted values, as described in section 3. The pleasing agreement with the predicted rotational constants, as seen in Table 5, confirms that GS rotational constants for single 13 C and single 18 F substitution can be predicted accurately.…”

Section: Semiexperimental Equilibrium Structuresmentioning

confidence: 99%

“…Fortunately, it appears that GS rotational constants for the singly substituted 13 C species can be predicted with useful accuracy, as shown with examples from the ct isomer in section 3. 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, 18 the 2-d 1 species, 19 and the 1-d 1 species 20 of the cc and tt isomers of DFBD.…”

Section: Introductionmentioning

confidence: 97%

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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: Discussionmentioning

confidence: 99%

Section: Prediction Of Rotational Constantsmentioning

confidence: 99%