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Structural and Theoretical Investigation of Anhydrous 3,4,5-Triacetoxybenzoic Acid.

ABSTRACT: A comprehensive investigation of anhydrous form of 3,4,5-Triacetoxybenzoic acid (TABA) is reported. Single crystal X-ray diffraction, Thermal analysis, Fourier Transform Infrared spectroscopy (FTIR) and DFT calculations were applied for TABA characterization. This anhydrous phase crystallizes in the triclinic [Formula: see text] space group (Z' = 1) and its packing shows a supramolecular motif in a classical [Formula: see text] ring formed by acid-acid groups association. The phase stability is accounted in terms of supramolecular architecture and its thermal behaviour. Conformation search at B3LYP/6-311++G(2d,p) level of theory shows the existence of three stable conformers and the most stable conformation was found experimentally. The reactivity of TABA was investigated using the molecular orbital theory and molecular electrostatic potential. The calculation results were used to simulate the infrared spectrum. There is a good agreement between calculated and experimental IR spectrum, which allowed the assignment of the normal vibrational modes.

SUBMITTER: Carvalho PS

PROVIDER: S-EPMC4927074 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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Structural and Theoretical Investigation of Anhydrous 3,4,5-Triacetoxybenzoic Acid.

Carvalho Paulo S PS Almeida Leonardo R LR Araújo Neto João H JH Medina Ana Carolina Q D AC Menezes Antonio C S AC Sousa José E F JE Oliveira Solemar S SS Camargo Ademir J AJ Napolitano Hamilton B HB

PloS one 20160629 6

A comprehensive investigation of anhydrous form of 3,4,5-Triacetoxybenzoic acid (TABA) is reported. Single crystal X-ray diffraction, Thermal analysis, Fourier Transform Infrared spectroscopy (FTIR) and DFT calculations were applied for TABA characterization. This anhydrous phase crystallizes in the triclinic [Formula: see text] space group (Z' = 1) and its packing shows a supramolecular motif in a classical [Formula: see text] ring formed by acid-acid groups association. The phase stability is ...[more]

PMID: 27355378

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Project description:BACKGROUND:Co-crystal is a structurally homogeneous crystalline material that contains two or more neutral building blocks that are present in definite stoichiometric amounts. The main advantage of co-crystals is their ability to generate a variety of solid forms of a drug that have distinct physicochemical properties from the solid co-crystal components. In the present investigation, five co-crystals containing 2-amino-6-chloropyridine (AMPY) moiety were synthesized and characterized. RESULTS:The crystal structure of 2-amino-6-chloropyridine (AMPY) (I), and the robustness of pyridine-acid supramolecular synthon were discussed in four stoichiometry co-crystals of AMPY…BA (II), AMPY…2ABA (III), AMPY…3CLBA (IV) and AMPY…4NBA (V). The abbreviated designations used are benzoic acid (BA), 2-aminobenzoic acid (2ABA), 3-chlorobenzoic acid (3CLBA) and 4-nitrobenzoic acid (4NBA). All the crystalline materials have been characterized by (1)HNMR, (13)CNMR, IR, photoluminescence, TEM analysis and X-ray diffraction. The supramolecular assembly of each co-crystal is analyzed and discussed. CONCLUSIONS:Extensive N---H?·?·?·?N/N---H?·?·?·?O/O---H?·?·?·?N hydrogen bonds are found in (I-V), featuring different supramolecular synthons. In the crystal structure, for compound (I), the 2-amino-6-chloropyridine molecules are linked together into centrosymmetric dimers by hydrogen bonds to form homosynthon, whereas for compounds (II-V), the carboxylic group of the respective acids (benzoic acid, 2-aminobenzoic acid, 3-chlorobenzoic acid and 4-nitrobenzoic acid) interacts with pyridine molecule in a linear fashion through a pair of N---H?·?·?·?O and O---H?·?·?·?N hydrogen bonds, generating cyclic hydrogen-bonded motifs with the graph-set notation [Formula: see text] , to form heterosynthon. In compound (II), another intermolecular N---H?·?·?·?O hydrogen bonds further link these heterosynthons into zig-zag chains. Whereas in compounds (IV) and (V), these heterosynthons are centrosymmetrically paired via N---H?·?·?·?O hydrogen bonds and each forms a complementary DADA [D?=?donor and A?=?acceptor] array of quadruple hydrogen bonds, with graph-set notation [Formula: see text], [Formula: see text] and [Formula: see text].

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Dataset Information

Structural and Theoretical Investigation of Anhydrous 3,4,5-Triacetoxybenzoic Acid.

Publications

Structural and Theoretical Investigation of Anhydrous 3,4,5-Triacetoxybenzoic Acid.

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