Barrier to the inversion of six-membered rings containing an sp2-hybridized carbon

Jensen, Frederick R.; Beck, Barbara Hardin

doi:10.1021/ja01006a045

Cited by 38 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…11 With this in mind, the block of the Hamil- until corrections are applied. A basic assumption is that the zero-point effects of the remaining vibrational modes are absorbed in the coefficients in the Hamiltonian and that the coupling of these modes to the ring-puckering vibration and to over-all rotation can otherwise be neglected.…”

Section: Analysis Of the Spectra For V=o And V=lmentioning

confidence: 99%

See 1 more Smart Citation

Microwave Spectrum, Ring-Puckering Potential Function, and Dipole Moment of Methylenecyclobutane

Scharpen

Laurie

1968

The Journal of Chemical Physics

View full text Add to dashboard Cite

The microwave spectra of methylenecyclobutane in the ground state and in the first six excited states of the ring-puckering vibration have been assigned. The 11=0 state and 11= 1 state are very close in energy and are strongly coupled giving rise to nonrigid-rotor spectra. Analysis shows the energy difference to be 33 592 MHz. This energy difference together with the vibrational dependence of the rotational constants gives the ring-puckering potentialfunction to be 7.65 (X'-9.15X1) em-I where X is a reduced ring-puckering coordinate. This potential function contains a barrier to ring inversion of 160±40 em-I. The a component of the dipole moment is found to be 0.514 D in the ground state and to have the ring-puckering vibrational dependence ~=0.496+0.0051 (XI) •• (debye). 10

show abstract

Section: Analysis Of the Spectra For V=o And V=lmentioning

confidence: 99%

“…11 where it is shown that the rotational constant dependence on vibrational state can be written if corrections are first applied to the experimental constants for v=O and 1. This has been treated in Ref.…”

Section: Analysis Of the Spectra For V=o And V=lmentioning

confidence: 99%

Microwave Spectrum, Ring-Puckering Potential Function, and Dipole Moment of Methylenecyclobutane

Scharpen

Laurie

1968

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…The free energy of activation characteristic of the underlying process was calculated to be 6.0 f 0.3 kcal/mol, at T,, by standard procedures (8) using a transmission coefficient of one half. Consideration of the absence of a spectral change for 1 down to -170" suggests that its corresponding AG' must be less than 5 kcal/mol (2,9).…”

Section: Resultsmentioning

confidence: 99%

“…The first one consists of the change from the chair to a boat form; it is followed by , through a n intermediate (6) having five carbon atoms in one plane, into the boat form (7) while the other [B] involves wagging the double bond, through a conformation (8) having six coplanar carbon atoms, into the boat form (9).…”

Section: 33mentioning

confidence: 99%

On the Mechanism of Ring Inversion in Cycloheptene and Its Derivatives

St‐Jacques¹,

Vaziri²

1973

Can. J. Chem.

View full text Add to dashboard Cite

Free energy barriers to ring inversion of 3,3-dimethyl-, 4,4-dimethyl-, and 5,s-dimethylcycloheptene were found to be much smaller than those of corresponding benzocycloheptene derivatives but show the same trend. This observation strongly suggests that the chair conformationof both types of molecules interconverts through the same mechanism. On the other hand, the AGf value for 4,4,6,6-tetramethylcycloheptene is about 3 kcal/mol out of line from that expected from a consideration of the behavior of the corresponding benzocycloheptene derivative. An explanation is offered.Les barrikres d'tnergie libre pour l'inversion des dimethyl-3,3, dimethyl-4,4 et dimethyl-5,5 cycloheptimes, tout en conservant la m&me tendance, sont plus faibles que celles qui caractkrisent les derives correspondants du benzocycloheptkne. Cette observation indique que la conformation chaise des deux classes de molecules s'inverse par le m&me mecanisme. Par contre, la valeur de AG+ pour le tetramethyl-4,4,6,6 cycloheptene est environ 3 kcal/mol plus elevke que celle attendue aprks examen des benzocycloheptknes correspondants. Une explication est presentee.

show abstract

“…Nous avons tentt d'ttendre ce type de corrtlation ti la cyclohexanone (AF* < 5 kcal/mole) (2) en considtrant la barribre de rotation interne de l'acttona (0.78 kcal/mole) (17) et celle de l'acttaldthyde (1.16 kcal/mole) (13). Dans ce cas, la relation entre les tnergies n'est plus vtrifite.…”

Section: X/xunclassified

Etude par résonance magnétique nucléaire à température variable de composés apparentés au méthylènecyclohexane

Bernard¹,

St‐Jacques²

1970

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

Barrier to the inversion of six-membered rings containing an sp2-hybridized carbon

Cited by 38 publications

References 0 publications

Microwave Spectrum, Ring-Puckering Potential Function, and Dipole Moment of Methylenecyclobutane

Microwave Spectrum, Ring-Puckering Potential Function, and Dipole Moment of Methylenecyclobutane

On the Mechanism of Ring Inversion in Cycloheptene and Its Derivatives

Etude par résonance magnétique nucléaire à température variable de composés apparentés au méthylènecyclohexane

Contact Info

Product

Resources

About