Journal ArticleDOI
Recurrence of carboxylic acid-pyridine supramolecular synthon in the crystal structures of some pyrazinecarboxylic acids.
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TLDR
X-ray crystal structures of pyrazinic acid 1 and isomeric methylpyrazine carboxylic acids 2-4 are analyzed to examine the occurrence of car boxylic acid-pyridine supramolecular synthon V in these heterocyclic acids.Abstract:
X-ray crystal structures of pyrazinic acid 1 and isomeric methylpyrazine carboxylic acids 2-4 are analyzed to examine the occurrence of carboxylic acid-pyridine supramolecular synthon V in these heterocyclic acids. Synthon V, assembled by (carboxyl)O-H...N(pyridine) and (pyridine)C-H...O(carbonyl) hydrogen bonds, controls self-assembly in the crystal structures of pyridine and pyrazine monocarboxylic acids. The recurrence of acid-pyridine heterodimer V compared to the more common acid-acid homodimer I in the crystal structures of pyridine and pyrazine monocarboxylic acids is explained by energy computations in the RHF 6-31G* basis set. Both the O-H.N and the C-H...O hydrogen bonds in synthon V result from activated acidic donor and basic acceptor atoms in 1-4. Pyrazine 2,3- and 2,5-dicarboxylic acids 10 and 11 crystallize as dihydrates with a (carboxyl)O-H...O(water) hydrogen bond in synthon VII, a recurring pattern in the diacid structures. In summary, the carboxylic acid group forms an O-H...N hydrogen bond in pyrazine monocarboxylic acids and an O-H...O hydrogen bond in pyrazine dicarboxylic acids. This structural analysis correlates molecular features with supramolecular synthons in pyridine and pyrazine carboxylic acids for future crystal engineering strategies.read more
Citations
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Journal ArticleDOI
Co-crystallisation of 2,2′-dithiodibenzoic acid with the isomeric n-pyridinealdazines, n = 2, 3 and 4: supramolecular polymers and the influence of steric factors upon aggregation patterns
TL;DR: The structure of the 1:1 co-crystal formed between the dicarboxylic acid, 2,2′-dithiodibenzoic acid, and each of the isomeric 3-and 4-pyridinealdazines features a supramolecular zig-zag chain constructed about the O-Hacid⋯Npyridine synthon.
Patent
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References
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Journal ArticleDOI
Supramolecular Synthons in Crystal Engineering—A New Organic Synthesis
TL;DR: In this article, the authors show that crystal engineering is a new organic synthesis, and that rather than being only nominally relevant to organic chemistry, this subject is well within the mainstream, being surprisingly similar to traditional organic synthesis in concept.
Journal ArticleDOI
Noncovalent synthesis using hydrogen bonding
TL;DR: Noncovalent synthesis based on the reversible formation of multiple hydrogen bonds is described and the development of novel materials (nanotubes, liquid crystals, polymers, etc.) and principles that recently have emanated from this intriguing field of research are summarized.
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Noncovalent Synthesis: Using Physical-Organic Chemistry To Make Aggregates
George M. Whitesides,Eric E. Simanek,John P. Mathias,Christopher T. Seto,Donovan N. Chin,Mathai Mammen,Dana M. Gordon +6 more
TL;DR: A molecule is usually understood to be a stable collection of atoms connected by a continuous network of covalent bonds as discussed by the authors, and the develipment of methods for constructing these networks has been a central occupation of organic chemistry, and the success of these methods has made possible the power, elegance and utility of modern organic synthesis.
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Photochemical reactions of organic crystals
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Superstructural diversity in two dimensions: crystal engineering of laminated solids
TL;DR: The application of self-assembly to the solid state offers an approach to crystal design and crystal engineering, namely supramolecular synthesis of solids, that is based upon the design of infinite networks.