Die optische Aktivität achiraler Substanzen

Claborn, Kacey; Isborn, Christine M.; Kaminsky, Werner; Kahr, Bart

doi:10.1002/ange.200704559

Cited by 11 publications

(12 citation statements)

References 101 publications

(57 reference statements)

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“…[20][21][22] The purpose of this work is to revisit the calculation of orientation-dependent electronic CD and optical rotation of oriented molecules. A simple way is described of how to incorporate GIAO OR and CD in a DFT/TDDFT package that already has the capability of computing dynamic electric polarizabilities or TDDFT excitation spectra as well as static GIAO magnetizabilities or NMR shielding tensors, without further modifications inside these modules.…”

Section: Introductionmentioning

confidence: 99%

Time‐Dependent Density Functional Theory for Calculating Origin‐Independent Optical Rotation and Rotatory Strength Tensors

Autschbach

2011

ChemPhysChem

124

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An approach to calculate origin-independent electronic chiroptical property tensors using time-dependent density functional theory (TDDFT) and gauge-including atomic orbital (GIAO) basis sets is evaluated. Computations of origin-dependent optical rotation tensors and of rotatory strengths needed to simulate circular dichroism spectra are presented. The optical rotation tensor computations employ solutions of coupled perturbed Kohn-Sham equations for a dynamic electric field and a static magnetic field. Because the magnetic field is time independent, the GIAO treatment is somewhat simplified compared to a previously reported method, at some added computational cost if hybrid functionals are employed. GIAO rotatory strengths are also calculated, using transition density matrices from a standard TDDFT excitation energy module. A new implementation in the NWChem quantum chemistry package is employed for representative computations of origin-invariant chiroptical response tensors for methyloxirane, norbornenone, and the ketosteroid androstadienone. For the steroid molecule the vibrational structure of the CD spectrum is modeled explicitly by using calculated Franck-Condon factors. The agreement with experiment is favorable.

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Section: Introductionmentioning

confidence: 99%

Time‐Dependent Density Functional Theory for Calculating Origin‐Independent Optical Rotation and Rotatory Strength Tensors

Autschbach

2011

ChemPhysChem

124

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“…For the three-hypotheses model (the structure is either correct, incorrect, or a 50 % inversion twin), the probabilities p3A C H T U N G T R E N N U N G (correct), p3A C H T U N G T R E N N U N G (twin), and p3(incorrect) that each of the hypotheses was right are given. [ www.chemeurj.org measurements (NLO), [16] CD spectroscopy, [17] and optical microscopy, [18] are useful to assess the presence of enantiomeric excess of both chiral and achiral compounds. To overcome these difficulties, solid-state techniques, such as solid-state VCD, are highly suitable because they combine the features of IR spectroscopy, which are dependent on the characteristics of the molecule and its solid-state supramolecular organization, with circular dichroism, which show different absorptions of right-and left-circularly polarized light and, thus, these techniques are sensitive to the handedness of the sample.…”

Section: Resultsmentioning

confidence: 99%

A Facile Method to Determine the Absolute Structure of Achiral Molecules: Supramolecular‐Tilt Structures

Tejedor

Uriel

Graus

et al. 2013

Chemistry A European J

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Achiral compounds 4-methoxy-4-(p-methoxyphenyl)cyclohexanoneethylene ketal (2), 4-hydroxy-4-(p-methoxy phenyl)cyclohexanoneethylene ketal (3), and 3,5-dimethyl-4-nitropyrazole (4) crystallized in chiral structures and the samples showed an enantiomeric excess. We have determined the absolute structures of these compounds by using X-ray diffraction with copper radiation at low temperatures. Moreover, we have also established the prevalent absolute structures in these samples, by comparing their calculated and solid-state vibrational circular dichroism (VCD) spectra. The consistency of this method was confirmed by using (R,R)-2,8-diiodo-4,10-dimethyl-6 H,12H-5,11-methano-dibenzo[b,f][1,5]diazocine, Tröger's base, (R,R)-1, as a chiral compound of known absolute configuration.

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“…It has been established that optical rotation actually does not necessarily require structural chirality [6] . Optical rotation and circular dichroism could also be allowed in non‐enantiomorphous but still non‐centrosymmetric crystal classes such as 42 m ( D 2d ), 4( S 4 ), m ( C s ) and mm 2( C 2v ) (Scheme 1a) [6a,b,7] . In the case of achiral crystal with mm 2 point group symmetry, optical rotation is allowed when the object contains a left‐ and right‐handed helix with their axes oriented along the direction of optical axes (Scheme 1b) [6c,8] .…”

Section: Introductionmentioning

confidence: 99%

Chiroptical Activity of An Achiral Emissive Eu Metal–Organic Framework

et al. 2023

Chemistry A European J

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Chiroptical activity of achiral crystals is theoretically allowed but very unusual. There is a particularly scarcity of empirical studies on optically active achiral metal-organic frameworks (MOFs). Herein we report an achiral emissive Eu MOF and its chiroptical properties both in the ground and excited states. The framework crystallizes in an achiral space group (Pna2 1 ) belonging to the polar point group (mm2), where the asymmetric arrangement of racemic trinuclear Euoxo clusters is responsible for the optical activity. A pair of circular dichroisms (CD) and circularly polarized luminescence (CPL) peaks with opposite signs were observed for single crystals. Importantly, the luminescence dissymmetry factor can reach up to 1.1 × 10 À 3 , which is comparable in magnitude to the value of most of the chiral-linker-bridged MOFs. This work gives the first example of achiral MOFs with CPL response and should be instructive for the discovery of more CPL emitters from racemic MOF family.

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Die optische Aktivität achiraler Substanzen

Cited by 11 publications

References 101 publications

Time‐Dependent Density Functional Theory for Calculating Origin‐Independent Optical Rotation and Rotatory Strength Tensors

Time‐Dependent Density Functional Theory for Calculating Origin‐Independent Optical Rotation and Rotatory Strength Tensors

A Facile Method to Determine the Absolute Structure of Achiral Molecules: Supramolecular‐Tilt Structures

Chiroptical Activity of An Achiral Emissive Eu Metal–Organic Framework

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