Optical activity due to isotopic substitution. Circular dichroism of (1R)-[2-18O]-.alpha.-fenchocamphoronequinone

Kokke, W. C. M. C.; Oosterhoff, L.J.

doi:10.1021/ja00776a054

Cited by 13 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8 the calculated CD spectrum for the second ͑1 1 AЈ → 1 1 AЉ͒ transition of 2b is presented, showing a good agreement with the experiment. 82 The positions of the different maxima of the CD band are reproduced very well up to about 4000 cm −1 ; with the increasing energy, however, the simulation seems to be stretched to higher energies which was also noted for 2a. Regarding the absolute intensities, the ⌬⑀ values of the simulated CD spectrum are slightly too small by a factor of 1.3 ͑see Table II͒ groups is shortened, as seen for the corresponding transition of 2a.…”

Section: B ␣-Diketone Carbonyl Chromophoresupporting

confidence: 53%

“…8 in comparison to the experimental spectrum. 82 In contrast to the results for 2a, a very good agreement with the experiment is obtained which is somewhat surprising since the same geometries and Hessians for the initial and final states as well as Cartesian derivatives of the electric and magnetic transition dipole moments have been used for both calculations. In addition, the absolute ⌬⑀ values are reproduced almost perfectly ͑see Table II͒.…”

Section: B ␣-Diketone Carbonyl Chromophorementioning

confidence: 76%

See 1 more Smart Citation

A theoretical study of the chiroptical properties of molecules with isotopically engendered chirality

Dierksen

Grimme

2006

The Journal of Chemical Physics

View full text Add to dashboard Cite

There has been a considerable interest in the chiroptical properties of molecules whose chirality is exclusively due to an isotopic substitution and numerous examples for the electronic circular dichroism (CD) spectra of isotopically chiral systems have been reported in literature. Four different explanations have been proposed for the mechanism as to how the isotopic substitution induces a chiral perturbation of the otherwise achiral electronic wave function; however, up to now no conclusive answer has been given about the dominating effect responsible for the experimental observations. In this study we will present, for the first time, fully quantum-mechanical calculations of the CD spectra of three different molecular systems with isotopically engendered chirality. As examples, we consider the spectra of organic molecules with ketone and alpha-diketone carbonyl and diene chromophores. The effect of vibronic couplings for the reorientation of the electric and magnetic transition dipole moments is taken into account within the Herzberg-Teller approximation. The ground and excited state geometries and vibrational normal modes are obtained with (time-dependent) density functional theory [(TD)DFT], while the vibronic coupling effects are calculated at the TDDFT and density functional theory/multireference configuration interaction (DFT/MRCI) levels of theory. Generally, the band shapes of the experimental CD spectra are reproduced very well, and also the absolute CD intensities from the simulations are of the right order of magnitude. The sign and the intensity of the CD band are determined by a delicate balance of the contributions of a large number of individual vibronic transitions, and it is found that the vibrational normal modes with a large displacement are dominant. The separation of the calculated CD spectrum into the different contributions due to the overlap of the in-plane and out-of-plane components (regarding the symmetry plane of the unsubstituted molecule) of the electric and magnetic transition dipole moments yields information about the influence of the vibronic coupling effects for the reorientation of the corresponding transition dipole moments. In conclusion, the calculations clearly show that vibronic effects are responsible or at least dominant for the chiroptical properties of isotopically chiral organic molecules.

show abstract

Section: B ␣-Diketone Carbonyl Chromophoresupporting

confidence: 53%

Section: B ␣-Diketone Carbonyl Chromophorementioning

confidence: 76%

A theoretical study of the chiroptical properties of molecules with isotopically engendered chirality

Dierksen

Grimme

2006

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…The CD spectrum of (lfi)-[2-180]-a-fenchocamphoronequinone has been recorded and is the only example of chiroptical measurements on an 160-180 dissymmetric molecule. 7 The other optically active 160-180 compounds, all aryl sulfones,8 have unfavorable rotation to absorption ratios which precluded CD or ORD measurements of Cotton effects.…”

Section: References and Notesmentioning

confidence: 99%

“…The ether was dried with anhydrous magnesium sulfate and removed in vacuo. Crystallization from dichloromethane-Skellysolve B gave 8.93 g (45%) of 2b: mp 112°; ir (KBr) 1700 (C-O), 1310 and 1150 cm-1 (S02); NMR (CDCla) 1.42 (t, J = 7 Hz, 3 H), 4.35 (s, 2 ), 4.40 (q, J = 7 Hz, 2 H), and 7.0-8.0 ppm (m, 9 -Bromo-p-Carbethoxybenzyl Phenyl Sulfone (lb). One gram (3.0 mmol) of 2b was dissolved in 15 ml of dry DMF in a dry 50-ml three-necked flask under a dry nitrogen atmosphere.…”

mentioning

confidence: 99%

[.alpha.,.alpha.-2H2]Dibenzyl sulfoxide. Synthesis, reactions, and chiroptic properties

Andersen¹,

Cinquini²,

Colonna³

et al. 1975

J. Org. Chem.

View full text Add to dashboard Cite

“…( 10) N. J. Turro, P. A. Leermakers, and G, F. Vesley, Org. Syn., 5,297 (1973). (11) Unpublished observations.…”

mentioning

confidence: 99%

Synthesis of (1R)-[1-D]-.alpha.-fenchocamphoronequinone

Kokke¹,

VARKEVISSER²

1974

J. Org. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

Optical activity due to isotopic substitution. Circular dichroism of (1R)-[2-18O]-.alpha.-fenchocamphoronequinone

Cited by 13 publications

References 2 publications

A theoretical study of the chiroptical properties of molecules with isotopically engendered chirality

A theoretical study of the chiroptical properties of molecules with isotopically engendered chirality

[.alpha.,.alpha.-2H2]Dibenzyl sulfoxide. Synthesis, reactions, and chiroptic properties

Synthesis of (1R)-[1-D]-.alpha.-fenchocamphoronequinone

Contact Info

Product

Resources

About