Optical rotation: Recent advances in determining the absolute configuration

Polavarapu, Prasad L.

doi:10.1002/chir.10145

Cited by 272 publications

(140 citation statements)

References 73 publications

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“…[21][22][23][24][25][26][27][28][29][30][31][32][33][34] Including vibrational effects in calculations of optical rotation is therefore also an important ingredient for obtaining results which are more reliable. [12,17,[35][36][37][38] Due to approximations in the treatment of electron correlation, basis set truncation, and neglect of solvent effects, consideration of vibrational corrections does not always improve the agreement with experiment since the "better" result including vibrational effects might expose error cancellations elsewhere in the computations. [24] Recently, we have developed a simple technique for calculating the temperature dependence of a molecular property from vibrational averaging.…”

Section: Introductionmentioning

confidence: 95%

Temperature Dependence of the Optical Rotation in Six Bicyclic Organic Molecules Calculated by Vibrational Averaging

Mort

Autschbach

2007

ChemPhysChem

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The vibrational corrections and the temperature dependence of the specific rotation of six rigid organic molecules (alpha-pinene, beta-pinene, cis-pinane, camphene, camphor, and fenchone) were calculated at three wavelengths using hybrid time-dependent density functional theory (TDDFT). A technique for calculating the temperature dependence of the vibrational average of a molecular property has been applied to obtain the specific rotation of the molecules as a function of temperature. For cases in which accurate equilibrium optical rotations can be obtained as a "base value," and for which there is little effect from solvation, accurate predictions of the trends in the temperature-dependence of the specific rotations can be calculated. For other cases, the method can be used to extract purely vibrational contributions to the overall temperature dependence of optical rotation.

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Section: Introductionmentioning

confidence: 95%

Temperature Dependence of the Optical Rotation in Six Bicyclic Organic Molecules Calculated by Vibrational Averaging

Mort

Autschbach

2007

ChemPhysChem

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“…[4] One of the most common methods for the determination of enantiomeric purity is the measurement of optical rotation. [5] In addition, NMR spectroscopy, [6] GC,and HPLC are also useful techniques. [7] As an alternative,circular dichroism (CD) has been used and recently brought to ah igh-throughput level.…”

Section: Introductionmentioning

confidence: 99%

Determination of Enantiomeric Excess in Amine Derivatives with Molecular Self‐Assemblies

et al. 2015

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Abstract:We report the first fluorescence-based assayf or the rapid determination of the ee value of amines,amino alcohols, and amino acid esters.The method uses the self-assembly of 2-formylphenylboronic acid with achiral diol and achiral amine or derivatives (of unknown chirality) to produce two diastereomeric iminoboronates that differ in their fluorescence intensity and polarization. The approach allows for the accurate determination of the ee value of chiral amines with errors of just 1-2 %. We believe that this application of orthogonal dynamic covalent self-assembly in the determination of the enantioselectivity will lead to the development of high-throughput procedures for the determination of chirality.

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“…Absolute differences between computations and experiment are bigger for smaller k, but relative differences are similar within the whole range. The absolute value of OR decreases with k and thus corresponds to the typical relation a 5 k/(k 2 2 k 2 0 ), 73 where k 0 is the wavelength of an electronic transition, k is the wavelength of light and k is a constant. Because the absolute values of optical rotation are bigger for smaller k, the short wave- Figure 5.…”

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confidence: 99%

Conformational behavior of simple furanosides studied by optical rotation

Kaminský¹,

Raich²,

Tomčáková³

et al. 2010

J Comput Chem

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Experimental and theoretical specific optical rotations (OR) of anhydro, epithio, and epiminoderivatives of methyl tetrofuranosides in chloroform solutions have been compared and used as a tool for exploring their conformational behavior. The potential energy surfaces of these saccharides with reduced flexibility were examined with the density functional theory and the MP2 and CCSD(T) wavefunctions methods. Theoretical ORs were obtained by Boltzmann averaging of values calculated for local minima. Resultant rotations could be used to assess the quality of the DFT and MP2 relative conformer energies. OR values calculated for equilibrium geometries in vacuum were significantly improved when the solvent was accounted for by a polarizable continuum model and first and diagonal second OR derivatives were used for an anharmonic vibrational averaging. The DFT used as a default method reproduced the experimental data fairly well. A modified B3LYP functional containing 70% of HF exchange further improved the results. Because of the strong dependence of OR on the conformation, not only the absolute configuration could be determined, but also the conformational populations were estimated. Likewise, the predicted dependence of OR on the light wavelength well agreed with experiment. The increasing precision of the contemporary computational methods thus makes it possible to relate the specific rotation to more detailed features in molecular structure.

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Optical rotation: Recent advances in determining the absolute configuration

Cited by 272 publications

References 73 publications

Temperature Dependence of the Optical Rotation in Six Bicyclic Organic Molecules Calculated by Vibrational Averaging

Temperature Dependence of the Optical Rotation in Six Bicyclic Organic Molecules Calculated by Vibrational Averaging

Determination of Enantiomeric Excess in Amine Derivatives with Molecular Self‐Assemblies

Conformational behavior of simple furanosides studied by optical rotation

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