The enigma of a (±)-tartaric acid–urea cocrystal

Kostyanovsky, Remir G.; Kostyanovsky, Vasilii R.; Кадоркина, Г. К.

doi:10.1016/j.mencom.2009.01.007

Cited by 11 publications

(15 citation statements)

References 2 publications

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“…Their occurrence falls to 16.5% in a sample of 3819 mirror-symmetric acentric space groups. Conversely, chiral space groups are hardly preferred in racemates, and -apart very few exceptions 19,20 -one anticipates inversion and/or reflection elements to be present for pairs of opposite enantiomers. However, the question on what factors influence the probability of inversion symmetry to occur remains open.…”

Section: Methodsmentioning

confidence: 99%

Rationalizing the Lacking of Inversion Symmetry in a Noncentrosymmetric Polar Racemate: An Experimental and Theoretical Study

Presti

Sist

Loconte

et al. 2014

Crystal Growth & Design

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The total charge density of PYRAC, a polar (Pca21) organic racemate with Z' = 2 was derived from high-resolution single-crystal X-ray diffraction data at T = 100(2) K and periodic DFT calculations.The PYRAC asymmetric unit consists of a hydrogen-bonded pair of conformationally different enantiomers, A and Bi, where the subscript 'i' indicates a reversed absolute configuration. The lattice stability was compared with that of centrosymmetric possibly competing structures, with the aim of understanding why a non-centrosymmetric lattice framework is obtained from a racemic mixture. The likelihood of specific intermolecular recognition processes among different conformers of PYRAC in the very first stages of nucleation was investigated by DFT simulations in vacuo. Two competing, equivalent interconversion pseudorotatory paths between the most stable A and the least stable B conformers were found. It results that molecules spend most of their time (≈ 53 %) in the A conformation, while the B one is far less populated (≈ 7 %). Therefore, centrosymmetric AAi adducts are formed very frequently in the reaction liquor, while the BBi ones are rare. Nevertheless, AAi pairs produce crystal forms with cohesive energies and densities significantly less favourable than those estimated for the non-centrosymmetric heterochiral ABi ones. Therefore, preference for Z' = 2 in conjunction with non-centrosymmetric point and space groups results from the thermodynamic control of the crystallization process. The capability of forming extended hydrogen bond chains throughout the lattice appears to be a prerequisite to bind together the fundamental ABi repeating units.

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Section: Methodsmentioning

confidence: 99%

Rationalizing the Lacking of Inversion Symmetry in a Noncentrosymmetric Polar Racemate: An Experimental and Theoretical Study

Presti

Sist

Loconte

et al. 2014

Crystal Growth & Design

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“…The tartrate/racemate quandary intrigued Louis Pasteur, [106,107] at the time a student of Biot. He carefully repeated the experiments [108] and was soon delighted to find hemihedral faces on crystals of sodium ammonium tartrate, a detail missed by both Mitscherlich and de la Provostaye (Figure 7 a).…”

Section: Methodsmentioning

confidence: 99%

“…[110] In the following years he continued studies of crystal and molecular asymmetry on many compounds, including optically active and racemic malates and aspartates. [107] In 1853, he prepared the third, optically inactive, isomer of tartaric acid, today known as meso-tartaric acid.…”

Section: Methodsmentioning

confidence: 99%

Chemical Crystallography before X‐ray Diffraction

Molčanov

Stilinović

2013

Angew Chem Int Ed

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“…Das Tartrat/Racemat-Dilemma faszinierte Louis Pasteur, [106,107] der zu dieser Zeit ein Student von Biot war. Er wiederholte die Experimente sorgfältig [108] und fand bald heraus, dass die Natriumammoniumtartrat-Kristalle hemiedrische Flächen aufwiesen -ein Detail, dass sowohl Mitscherlich als auch de la Provostaye entgangen war (Abbildung 7 a).…”

Section: Angewandte Essaysunclassified

“…B. von optisch aktiven und racemischen Malaten und Aspartaten. [107] Im Jahr 1853 stellte er ein drittes, optisch inaktives, Isomer der Weinsäure her, das heute als meso-Weinsäure bekannt ist.…”

Section: Angewandte Essaysunclassified

Die chemische Kristallographie vor der Röntgenbeugung

Molčanov

Stilinović

2013

Angewandte Chemie

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In die Jahre 2012 und 2013 fallen die 100. Jahrestage der Röntgenbeugung an Kupfersulfat‐Einkristallen durch Laue, der Postulierung des Braggschen Gesetzes sowie der ersten Strukturbestimmung mit Röntgenmethoden. Die Beschäftigung mit Kristallen war jedoch schon vor 1912 ein integraler Bestandteil der Chemie und trug wesentlich zu ihrer Entwicklung als moderne Wissenschaft, zu Konzepten wie Atom, Molekül, Isomerie und Chiralität bei.

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The enigma of a (±)-tartaric acid–urea cocrystal

Cited by 11 publications

References 2 publications

Rationalizing the Lacking of Inversion Symmetry in a Noncentrosymmetric Polar Racemate: An Experimental and Theoretical Study

Rationalizing the Lacking of Inversion Symmetry in a Noncentrosymmetric Polar Racemate: An Experimental and Theoretical Study

Chemical Crystallography before X‐ray Diffraction

Die chemische Kristallographie vor der Röntgenbeugung

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