Theoretical and experimental investigations of the electronic circular dichroism and absorption spectra of bicyclic ketones

Pulm, Friedhelm; Schramm, Jörg; Hormes, J.; Grimme, Stefan; Peyerimhoff, Sigrid D.

doi:10.1016/s0301-0104(97)00258-9

Cited by 95 publications

(135 citation statements)

References 31 publications

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“…For the other cases, signs and relative magnitudes of the rotatory strengths as compared to the experimental estimates by Moscowitz are reasonable. Unlike other cases mentioned in the literature, 52 for which the computed rotatory strengths do not seem to depend strongly on the chosen geometry, we find that this is not the case for the samples here. Employing the idealized geometries of Refs.…”

Section: Cyclohexanone Derivativescontrasting

confidence: 88%

Chiroptical properties from time-dependent density functional theory. I. Circular dichroism spectra of organic molecules

Autschbach

Ziegler

Gisbergen³

et al. 2002

The Journal of Chemical Physics

413

330

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We report the implementation of the computation of rotatory strengths, based on time-dependent density functional theory, within the Amsterdam Density Functional program. The code is applied to the simulation of circular dichroism spectra of small and moderately sized organic molecules, such as oxiranes, aziridines, cyclohexanone derivatives, and helicenes. Results agree favorably with experimental data, and with theoretical results for molecules that have been previously investigated by other authors. The efficient algorithms allow for the simulation of CD spectra of rather large molecules at a reasonable accuracy based on first-principles theory. The choice of the Kohn-Sham potential is a critical issue. It is found that standard gradient corrected functionals often yield the correct shape of the spectrum, but the computed excitation energies are systematically underestimated for the samples being studied. The recently developed exchange-correlation potentials ''GRAC'' and ''SAOP'' often yield much better agreement here with experiments for the excitation energies. The rotatory strengths of individual transitions are usually improved by these potentials as well.

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Section: Cyclohexanone Derivativescontrasting

confidence: 88%

Chiroptical properties from time-dependent density functional theory. I. Circular dichroism spectra of organic molecules

Autschbach

Ziegler

Gisbergen³

et al. 2002

The Journal of Chemical Physics

413

330

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“…Also the spectra at ∆V s ) 1 are rather similar for the two molecules, consisting of a strong absorption band on the high-frequency side (ca. 2960 cm -1 ) in correspondence of CH 3 and CH 2 antisymmetric normal modes, 15,30,31 a prominent shoulder at ca. 2930 cm -1 , and a weaker band at ca.…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12] We had already published in the past some NIR-VCD data for 1 and 2 and for some related compounds. 13,14 However, we have recently improved our apparatus for measuring NIR-VCD, obtaining better VCD data in the overtone region at ∆V ) 3, new VCD data at ∆V ) 4 for fenchone, and VCD data in the yet unexplored regions of CH-stretchings/HCH-bendings combinations.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of Overtone CH-Stretching Vibrational Circular Dichroism Spectra of Fenchone and Camphor

et al. 2004

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Near-infrared vibrational circular dichroism (VCD) spectra in the region 1500−850 nm are recorded for both enantiomers of camphor and fenchone using a home-built dispersive instrument. Two CH-stretching overtone regions and two CH-stretching/HCH-bending combination regions are investigated. The near-infrared VCD data are examined and compared with the corresponding previously published data of (3R)-(+)-methylcyclopentanone and (3R)-(+)-methylcyclohexanone. The absorption spectra of both the fundamental and overtone regions are also considered, and the fundamental CH-stretching VCD data are taken into account, where possible. An empirical assignment of the spectra is first considered, with special regard to the second CH-stretching overtone region. This region is then investigated by a heuristic approach based on DFT calculations, using the hybrid functional B3LYP at the 6-31G** basis set level. Subsequently rotational strengths have been evaluated by use of a classical model based on the contribution of polarizable groups to the optical activity. The same models are also used to interpret the VCD spectra between 2000 and 3000 wavenumbers for (3R)-(+)-methylcyclopentanone-d 4.

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“…17 Some other factors that can lead to a disagreement with experimental data are: ͑i͒ Errors in the optimized molecular geometries. Other authors have previously found 47 that for the simulation of CD spectra of certain rigid camphor derivatives, the results were only weakly influenced by the choice of different computational models for the geometry optimization ͑Hartree-Fock versus semiempirical PM3͒. However, other cases also involving rigid molecules have shown a strong sensitivity of rotatory strengths on small changes in the optimized geom- etry, SCF convergence, etc., 14 and we might consequently expect a pronounced sensitivity of optical rotations with respect to the molecular geometry in selected cases here as well.…”

Section: Discussionmentioning

confidence: 99%

Chiroptical properties from time-dependent density functional theory. II. Optical rotations of small to medium sized organic molecules

Autschbach

Patchkovskii

Ziegler

et al. 2002

The Journal of Chemical Physics

191

162

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We report an implementation for the computation of optical rotations within the Amsterdam Density Functional program package. The code is based on time-dependent density functional response theory. Optical rotations have been calculated for a test set of 36 organic molecules with various density functionals, and employing basis sets of different quality. The results obtained in this work with nonhybrid functionals are comparable in quality to those recently reported by other authors for the B3LYP hybrid functional, but show a somewhat larger tendency to produce outlyers. The median error is approximately 20°/(dm g/cm 3 ) for specific rotations ͓␣͔ D as compared to experimental data ͑approximately 30% median deviation from experimental values͒. Thereby it is demonstrated that density functional computations can be employed to assist with the solution of stereochemical problems in case the specific rotations of the species involved are not small and their structures are rigid. Recent newly developed functionals are investigated with respect to their applicability in computations of optical rotations.

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Theoretical and experimental investigations of the electronic circular dichroism and absorption spectra of bicyclic ketones

Cited by 95 publications

References 31 publications

Chiroptical properties from time-dependent density functional theory. I. Circular dichroism spectra of organic molecules

Chiroptical properties from time-dependent density functional theory. I. Circular dichroism spectra of organic molecules

A Comparative Study of Overtone CH-Stretching Vibrational Circular Dichroism Spectra of Fenchone and Camphor

Chiroptical properties from time-dependent density functional theory. II. Optical rotations of small to medium sized organic molecules

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