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1.
Yara Santiago de Oliveira Wendell Saraiva Costa Poliana Ferreira Borges Maria Silmara Alves de Santana Alejandro Pedro Ayala 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(5):483-495
The use of supramolecular synthons as a strategy to control crystalline structure is a crucial factor in developing new solid forms with physicochemical properties optimized by design. However, to achieve this objective, it is necessary to understand the intermolecular interactions in the context of crystal packing. The feasibility of a given synthon depends on its flexibility to combine the drug with a variety of coformers. In the present work, the imidazole–hydroxy synthon is investigated using as the target molecule benzoylmetronidazole [BZMD; systematic name 2‐(2‐methyl‐5‐nitro‐1H‐imidazol‐1‐yl)ethyl benzoate], whose imidazole group seems to be a suitable acceptor for hydrogen bonds. Thus, coformers with carboxylic acid and phenol groups were chosen. According to the availability of binding sites presented in the coformer, and considering the proposed synthon and hydrogen‐bond complementarity as major factors, different drug–coformer stoichiometric ratios were explored (1:1, 2:1 and 3:1). Thirteen new solid forms (two salts and eleven cocrystals) were produced, namely BZMD–benzoic acid (1/1), C13H13N3O4·C7H6O2, BZMD–β‐naphthol (1/1), C13H13N3O4·C10H8O, BZMD–4‐methoxybenzoic acid (1/1), C13H13N3O4·C8H8O3, BZMD–3,5‐dinitrobenzoic acid (1/1), C13H13N3O4·C7H4N2O6, BZMD–3‐aminobenzoic acid (1/1), C13H13N3O4·C7H7NO2, BZMD–salicylic acid (1/1), C13H13N3O4·C7H6O3, BZMD–maleic acid (1/1) {as the salt 1‐[2‐(benzoyloxy)ethyl]‐2‐methyl‐5‐nitro‐1H‐imidazol‐3‐ium 3‐carboxyprop‐2‐enoate}, C13H14N3O4+·C4H3O4?, BZMD–isophthalic acid (1/1), C13H13N3O4·C8H6O4, BZMD–resorcinol (2/1), 2C13H13N3O4·C6H6O2, BZMD–fumaric acid (2/1), C13H13N3O4·0.5C4H4O4, BZMD–malonic acid (2/1), 2C13H13N3O4·C3H2O4, BZMD–2,6‐dihydroxybenzoic acid (1/1) {as the salt 1‐[2‐(benzoyloxy)ethyl]‐2‐methyl‐5‐nitro‐1H‐imidazol‐3‐ium 2,6‐dihydroxybenzoate}, C13H14N3O4+·C7H5O4?, and BZMD–3,5‐dihydroxybenzoic acid (3/1), 3C13H13N3O4·C7H6O4, and their crystalline structures elucidated, confirming the robustness of the selected synthon. 相似文献
2.
Valeska Gerhardt Maya Tutughamiarso Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(2):o92-o98
Hydantoin‐5‐acetic acid [2‐(2,5‐dioxoimidazolidin‐4‐yl)acetic acid] and orotic acid (2,6‐dioxo‐1,2,3,6‐tetrahydropyrimidine‐4‐carboxylic acid) each contain one rigid acceptor–donor–acceptor hydrogen‐bonding site and a flexible side chain, which can adopt different conformations. Since both compounds may be used as coformers for supramolecular complexes, they have been crystallized in order to examine their conformational preferences, giving solvent‐free hydantoin‐5‐acetic acid, C5H6N2O4, (I), and three crystals containing orotic acid, namely, orotic acid dimethyl sulfoxide monosolvate, C5H4N2O4·C2H6OS, (IIa), dimethylammonium orotate–orotic acid (1/1), C2H8N+·C5H3N2O4−·C5H4N2O4, (IIb), and dimethylammonium orotate–orotic acid (3/1), 3C2H8N+·3C5H3N2O4−·C5H4N2O4, (IIc). The crystal structure of (I) shows a three‐dimensional network, with the acid function located perpendicular to the ring. Interestingly, the hydroxy O atom acts as an acceptor, even though the carbonyl O atom is not involved in any hydrogen bonds. However, in (IIa), (IIb) and (IIc), the acid functions are only slightly twisted out of the ring planes. All H atoms of the acidic functions are directed away from the rings and, with respect to the carbonyl O atoms, they show an antiperiplanar conformation in (I) and synperiplanar conformations in (IIa), (IIb) and (IIc). Furthermore, in (IIa), (IIb) and (IIc), different conformations of the acid O=C—C—N torsion angle are observed, leading to different hydrogen‐bonding arrangements depending on their conformation and composition. 相似文献
3.
Balasubramanian Sridhar 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(12):1042-1047
Multicomponent crystals or cocrystals play a significant role in crystal engineering, the main objective of which is to understand the role of intermolecular interactions and to utilize such understanding in the design of novel crystal structures. Molecules possessing carboxylic acid and amide functional groups are good candidates for forming cocrystals. β‐Resorcylic acid monohydrate, C7H6O4·H2O, (I), crystallizes in the triclinic space group P with one β‐resorcylic acid molecule and one water molecule in the asymmetric unit. The cocrystal thymine–β‐resorcylic acid–water (1/1/1), C5H6N2O2·C7H6O4·H2O, (II), crystallizes in the orthorhombic space group Pca21, with one molecule each of thymine, β‐resorcylic acid and water in the asymmetric unit. All available donor and acceptor atoms in (I) and (II) are utilized for hydrogen bonding. The acid and amide functional groups are well known for the formation of self‐complementary acid–acid and amide–amide homosynthons. In (I), an acid–acid homosynthon is observed, while in (II), an amide–acid heterosynthon is present. In (I), the β‐resorcylic acid molecule exhibits the expected intramolecular S(6) motif between the hydroxy and carbonyl O atoms, and an intermolecular R22(8) dimer motif between the carboxylic acid groups; only the former motif is observed in (II). The water solvent molecule in (I) propagates the discrete dimers into two‐dimensional hydrogen‐bonded sheets. In (II), thymine and β‐resorcylic acid molecules do not form self‐complementary amide–amide and acid–acid homosynthons; instead, a thymine–β‐resorcylic acid heterosynthon is observed. With the help of the water molecule, this heterosynthon is aggregated into a three‐dimensional hydrogen‐bonded network. The absence of thymine base pairing in (II) might be linked to the availability of additional functional groups and the preference of the donor and acceptor hydrogen‐bond combinations. 相似文献
4.
Quoc Cuong Ton Ernst Egert 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(1):75-79
The antibiotic trimethoprim [5‐(3,4,5‐trimethoxybenzyl)pyrimidine‐2,4‐diamine] was cocrystallized with glutarimide (piperidine‐2,6‐dione) and its 3,3‐dimethyl derivative (4,4‐dimethylpiperidine‐2,6‐dione). The cocrystals, viz. trimethoprim–glutarimide (1/1), C14H18N4O3·C5H7NO2, (I), and trimethoprim–3,3‐dimethylglutarimide (1/1), C14H18N4O3·C7H11NO2, (II), are held together by three neighbouring hydrogen bonds (one central N—H...N and two N—H...O) between the pyrimidine ring of trimethoprim and the imide group of glutarimide, with an ADA/DAD pattern (A = acceptor and D = donor). These heterodimers resemble two known cocrystals of trimethoprim with barbituric acid and its 5,5‐diethyl derivative. Trimethoprim shows a conformation in which the planes of the pyrimidine and benzene rings are approximately perpendicular to one another. In its glutarimide coformer, five of the six ring atoms lie in a common plane; the C atom opposite the N atom deviates by about 0.6 Å. The crystal packing of each of the two cocrystals is characterized by an extended network of hydrogen bonds and contains centrosymmetrically related trimethoprim homodimers formed by a pair of N—H...N hydrogen bonds. This structural motif occurs in five of the nine published crystal structures in which neutral trimethoprim is present. 相似文献
5.
Valeska Gerhardt Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(1):19-25
Four crystal structures of 3‐cyano‐6‐hydroxy‐4‐methyl‐2‐pyridone (CMP), viz. the dimethyl sulfoxide monosolvate, C7H6N2O2·C2H6OS, (1), the N,N‐dimethylacetamide monosolvate, C7H6N2O2·C4H9NO, (2), a cocrystal with 2‐amino‐4‐dimethylamino‐6‐methylpyrimidine (as the salt 2‐amino‐4‐dimethylamino‐6‐methylpyrimidin‐1‐ium 5‐cyano‐4‐methyl‐6‐oxo‐1,6‐dihydropyridin‐2‐olate), C7H13N4+·C7H5N2O2−, (3), and a cocrystal with N,N‐dimethylacetamide and 4,6‐diamino‐2‐dimethylamino‐1,3,5‐triazine [as the solvated salt 2,6‐diamino‐4‐dimethylamino‐1,3,5‐triazin‐1‐ium 5‐cyano‐4‐methyl‐6‐oxo‐1,6‐dihydropyridin‐2‐olate–N,N‐dimethylacetamide (1/1)], C5H11N6+·C7H5N2O2−·C4H9NO, (4), are reported. Solvates (1) and (2) both contain the hydroxy group in a para position with respect to the cyano group of CMP, acting as a hydrogen‐bond donor and leading to rather similar packing motifs. In cocrystals (3) and (4), hydrolysis of the solvent molecules occurs and an in situ nucleophilic aromatic substitution of a Cl atom with a dimethylamino group has taken place. Within all four structures, an R22(8) N—H...O hydrogen‐bonding pattern is observed, connecting the CMP molecules, but the pattern differs depending on which O atom participates in the motif, either the ortho or para O atom with respect to the cyano group. Solvents and coformers are attached to these arrangements via single‐point O—H...O interactions in (1) and (2) or by additional R44(16) hydrogen‐bonding patterns in (3) and (4). Since the in situ nucleophilic aromatic substitution of the coformers occurs, the possible Watson–Crick C–G base‐pair‐like arrangement is inhibited, yet the cyano group of the CMP molecules participates in hydrogen bonds with their coformers, influencing the crystal packing to form chains. 相似文献
6.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(1):21-30
Doubly and triply hydrogen‐bonded supramolecular synthons are of particular interest for the rational design of crystal and cocrystal structures in crystal engineering since they show a high robustness due to their high stability and good reliability. The compound 5‐methyl‐2‐thiouracil (2‐thiothymine) contains an ADA hydrogen‐bonding site (A = acceptor and D = donor) if the S atom is considered as an acceptor. We report herein the results of cocrystallization experiments with the coformers 2,4‐diaminopyrimidine, 2,4‐diamino‐6‐phenyl‐1,3,5‐triazine, 6‐amino‐3H‐isocytosine and melamine, which contain complementary DAD hydrogen‐bonding sites and, therefore, should be capable of forming a mixed ADA–DAD N—H…S/N—H…N/N—H…O synthon (denoted synthon 3sN·S;N·N;N·O), consisting of three different hydrogen bonds with 5‐methyl‐2‐thiouracil. The experiments yielded one cocrystal and five solvated cocrystals, namely 5‐methyl‐2‐thiouracil–2,4‐diaminopyrimidine (1/2), C5H6N2OS·2C4H6N4, (I), 5‐methyl‐2‐thiouracil–2,4‐diaminopyrimidine–N,N‐dimethylformamide (2/2/1), 2C5H6N2OS·2C4H6N4·C3H7NO, (II), 5‐methyl‐2‐thiouracil–2,4‐diamino‐6‐phenyl‐1,3,5‐triazine–N,N‐dimethylformamide (2/2/1), 2C5H6N2OS·2C9H9N5·C3H7NO, (III), 5‐methyl‐2‐thiouracil–6‐amino‐3H‐isocytosine–N,N‐dimethylformamide (2/2/1), (IV), 2C5H6N2OS·2C4H6N4O·C3H7NO, (IV), 5‐methyl‐2‐thiouracil–6‐amino‐3H‐isocytosine–N,N‐dimethylacetamide (2/2/1), 2C5H6N2OS·2C4H6N4O·C4H9NO, (V), and 5‐methyl‐2‐thiouracil–melamine (3/2), 3C5H6N2OS·2C3H6N6, (VI). Synthon 3sN·S;N·N;N·O was formed in three structures in which two‐dimensional hydrogen‐bonded networks are observed, while doubly hydrogen‐bonded interactions were formed instead in the remaining three cocrystals whereby three‐dimensional networks are preferred. As desired, the S atoms are involved in hydrogen‐bonding interactions in all six structures, thus illustrating the ability of sulfur to act as a hydrogen‐bond acceptor and, therefore, its value for application in crystal engineering. 相似文献
7.
Wilhelm Maximilian Hützler Ernst Egert Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(8):634-646
The understanding of intermolecular interactions is a key objective of crystal engineering in order to exploit the derived knowledge for the rational design of new molecular solids with tailored physical and chemical properties. The tools and theories of crystal engineering are indispensable for the rational design of (pharmaceutical) cocrystals. The results of cocrystallization experiments of the antithyroid drug 6‐propyl‐2‐thiouracil (PTU) with 2,4‐diaminopyrimidine (DAPY), and of 6‐methoxymethyl‐2‐thiouracil (MOMTU) with DAPY and 2,4,6‐triaminopyrimidine (TAPY), respectively, are reported. PTU and MOMTU show a high structural similarity and differ only in the replacement of a methylene group (–CH2–) with an O atom in the side chain, thus introducing an additional hydrogen‐bond acceptor in MOMTU. Both molecules contain an ADA hydrogen‐bonding site (A = acceptor and D = donor), while the coformers DAPY and TAPY both show complementary DAD sites and therefore should be capable of forming a mixed ADA/DAD synthon with each other, i.e. N—H…O, N—H…N and N—H…S hydrogen bonds. The experiments yielded one solvated cocrystal salt of PTU with DAPY, four different solvates of MOMTU, one ionic cocrystal of MOMTU with DAPY and one cocrystal salt of MOMTU with TAPY, namely 2,4‐diaminopyrimidinium 6‐propyl‐2‐thiouracilate–2,4‐diaminopyrimidine–N,N‐dimethylacetamide–water (1/1/1/1) (the systematic name for 6‐propyl‐2‐thiouracilate is 6‐oxo‐4‐propyl‐2‐sulfanylidene‐1,2,3,6‐tetrahydropyrimidin‐1‐ide), C4H7N4+·C7H9N2OS−·C4H6N4·C4H9NO·H2O, (I), 6‐methoxymethyl‐2‐thiouracil–N,N‐dimethylformamide (1/1), C6H8N2O2S·C3H7NO, (II), 6‐methoxymethyl‐2‐thiouracil–N,N‐dimethylacetamide (1/1), C6H8N2O2S·C4H9NO, (III), 6‐methoxymethyl‐2‐thiouracil–dimethyl sulfoxide (1/1), C6H8N2O2S·C2H6OS, (IV), 6‐methoxymethyl‐2‐thiouracil–1‐methylpyrrolidin‐2‐one (1/1), C6H8N2O2S·C5H9NO, (V), 2,4‐diaminopyrimidinium 6‐methoxymethyl‐2‐thiouracilate (the systematic name for 6‐methoxymethyl‐2‐thiouracilate is 4‐methoxymethyl‐6‐oxo‐2‐sulfanylidene‐1,2,3,6‐tetrahydropyrimidin‐1‐ide), C4H7N4+·C6H7N2O2S−, (VI), and 2,4,6‐triaminopyrimidinium 6‐methoxymethyl‐2‐thiouracilate–6‐methoxymethyl‐2‐thiouracil (1/1), C4H8N5+·C6H7N2O2S−·C6H8N2O2S, (VII). Whereas in (I) only an AA/DD hydrogen‐bonding interaction was formed, the structures of (VI) and (VII) both display the desired ADA/DAD synthon. Conformational studies on the side chains of PTU and MOMTU also revealed a significant deviation for cocrystals (VI) and (VII), leading to the desired enhancement of the hydrogen‐bond pattern within the crystal. 相似文献
8.
Hiroyuki Hosomi Shigeru Ohba Yoshikatsu Ito 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e144-e146
In the title four compounds, C13H11N·C7H4N2O6, (I), C15H15N·C7H4N2O6, (II), C16H17N·C7H4N2O6, (III), and C16H17N·C7H4N2O6, (IV), the donor and acceptor molecules are stacked alternately to form one‐dimensional columns. In (I), the N‐methyl group of the donor is nearly eclipsed with respect to one of the nitro groups of the neighboring acceptor in a column, whereas the N‐isopropyl, N‐butyl and N‐isobutyl groups are in anti positions with respect to one of the nitro groups of the neighboring acceptor in compounds (II)–(IV). 相似文献
9.
Zhen‐Hua Wu Jian‐Ping Ma Xiang‐Wen Wu Ru‐Qi Huang Yu‐Bin Dong 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(4):o128-o130
Two different tautomeric forms of a new Schiff base, C17H19N3O2·C17H19N3O2, are present in the crystal in a 1:1 ratio, namely the enol–imine form 4‐(1‐{[4‐(dimethylamino)benzylidene]hydrazono}ethyl)benzene‐1,3‐diol and the keto–amine form 6‐[(E)‐1‐{[4‐(dimethylamino)benzylidene]hydrazino}ethylidene]‐3‐hydroxycyclohexa‐2,4‐dien‐1‐one. The tautomers are formed by proton transfer between the hydroxy O atom and the imine N atom and are hydrogen bonded to each other to form a one‐dimensional zigzag chain along the crystallographic b axis via intermolecular hydrogen bonds. 相似文献
10.
Valeska Gerhardt Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(1):84-93
It is well known that pyrimidin‐4‐one derivatives are able to adopt either the 1H‐ or the 3H‐tautomeric form in (co)crystals, depending on the coformer. As part of ongoing research to investigate the preferred hydrogen‐bonding patterns of active pharmaceutical ingredients and their model systems, 2‐amino‐6‐chloropyrimidin‐4‐one and 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4‐one have been cocrystallized with several coformers and with each other. Since Cl and Br atoms both have versatile possibilities to interact with the coformers, such as via hydrogen or halogen bonds, their behaviour within the crystal packing was also of interest. The experiments yielded five crystal structures, namely 2‐aminopyridin‐1‐ium 2‐amino‐6‐chloro‐4‐oxo‐4H‐pyrimidin‐3‐ide–2‐amino‐6‐chloropyrimidin‐4(3H)‐one (1/3), C5H7N2+·C4H3ClN3O−·3C4H4ClN3O, (Ia), 2‐aminopyridin‐1‐ium 2‐amino‐6‐chloro‐4‐oxo‐4H‐pyrimidin‐3‐ide–2‐amino‐6‐chloropyrimidin‐4(3H)‐one–2‐aminopyridine (2/10/1), 2C5H7N2+·2C4H3ClN3O−·10C4H4ClN3O·C5H6N2, (Ib), the solvent‐free cocrystal 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(1H)‐one (1/1), C5H6BrN3O·C5H6BrN3O, (II), the solvate 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(1H)‐one–N‐methylpyrrolidin‐2‐one (1/1/1), C5H6BrN3O·C5H6BrN3O·C5H9NO, (III), and the partial cocrystal 2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐5‐bromo‐6‐methylpyrimidin‐4(1H)‐one–2‐amino‐6‐chloropyrimidin‐4(3H)‐one (0.635/1/0.365), C5H6BrN3O·C5H6BrN3O·C4H4ClN3O, (IV). All five structures show R22(8) hydrogen‐bond‐based patterns, either by synthon 2 or by synthon 3, which are related to the Watson–Crick base pairs. 相似文献
11.
Nikolay N. Sveshnikov Michael H. Dickman Michael T. Pope 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1193-1195
The title structure, [Rh2(C7H5O3)4(C2H6OS)2]·[Rh2(C4H7O2)4(C2H6OS)2]·2C2H6O, contains two discrete neutral Rh–Rh dimers cocrystallized as the ethanol disolvate. Each dimer is situated on an inversion center. The butyrate chain displays disorder in one C‐atom position. In each dimer, the dimethyl sulfoxide ligand (dmso) is bound via S, as expected. The ethanol is a hydrogen‐bond acceptor for one p‐hydroxybenzoate hydroxyl group and acts as a hydrogen‐bond donor to the dmso O atom of a neighboring p‐hydroxybenzoate dirhodium complex. A third hydrogen bond is formed from the other p‐hydroxybenzoate hydroxyl group to the dmso O atom of a butyrate–dirhodium complex. 相似文献
12.
Alexander Bechtoldt Hans‐Wolfram Lerner Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(6):448-451
The aurophilicity exhibited by AuI complexes depends strongly on the nature of the supporting ligands present and the length of the Au–element (Au—E) bond may be used as a measure of the donor–acceptor properties of the coordinated ligands. A binuclear iron–gold complex, [1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene‐2κC2]dicarbonyl‐1κ2C‐(1η5‐cyclopentadienyl)gold(I)iron(II)(Au—Fe) benzene trisolvate, [AuFe(C5H5)(C27H36N2)(CO)2]·3C6H6, was prepared by reaction of K[CpFe(CO)2] (Cp is cyclopentadienyl) with (NHC)AuCl [NHC = 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene]. In addition to the binuclear complex, the asymmetric unit contains three benzene solvent molecules. This is the first example of a two‐coordinated Au atom bonded to an Fe and a C atom of an N‐heterocyclic carbene. 相似文献
13.
Augusto Rivera James Guevara‐Pulido John Sadat‐Bernal Jaime Ríos‐Motta Guillermo Zaragoza 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(9):o435-o437
The title compound, 1,5:3,7‐dimethano‐1,3,5,7‐benzotetrazonine–hydroquinone (2/1), 2C11H14N4·C6H6O2, crystallizes with the hydroquinone molecule located on a center of inversion. In contrast to other hydroquinone–adamanzane adducts, which form extended hydrogen‐bonded networks, in the present case, one hydroquinone molecule is linked to two 1,5:3,7‐dimethano‐1,3,5,7‐benzotetrazonine molecules, forming a 2:1 cluster through O—H...N hydrogen bonds. 相似文献
14.
Hendrik Klien Wilhelm Seichter Konstantinos Skobridis Edwin Weber 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(9):768-775
Having reference to an elongated structural modification of 2,2′‐bis(hydroxydiphenylmethyl)biphenyl, (I), the two 1,1′:4′,1′′‐terphenyl‐based diol hosts 2,2′′‐bis(hydroxydiphenylmethyl)‐1,1′:4′,1′′‐terphenyl, C44H34O2, (II), and 2,2′′‐bis[hydroxybis(4‐methylphenyl)methyl]‐1,1′:4′,1′′‐terphenyl, C48H42O2, (III), have been synthesized and studied with regard to their crystal structures involving different inclusions, i.e. (II) with dimethylformamide (DMF), C44H34O2·C2H6NO, denoted (IIa), (III) with DMF, C48H42O2·C2H6NO, denoted (IIIa), and (III) with acetonitrile, C48H42O2·CH3CN, denoted (IIIb). In the solvent‐free crystals of (II) and (III), the hydroxy H atoms are involved in intramolecular O—H...π hydrogen bonding, with the central arene ring of the terphenyl unit acting as an acceptor. The corresponding crystal structures are stabilized by intermolecular C—H...π contacts. Due to the distinctive acceptor character of the included DMF solvent species in the crystal structures of (IIa) and (IIIa), the guest molecule is coordinated to the host via O—H...O=C hydrogen bonding. In both crystal structures, infinite strands composed of alternating host and guest molecules represent the basic supramolecular aggregates. Within a given strand, the O atom of the solvent molecule acts as a bifurcated acceptor. Similar to the solvent‐free cases, the hydroxy H atoms in inclusion structure (IIIb) are involved in intramolecular hydrogen bonding, and there is thus a lack of host–guest interaction. As a result, the solvent molecules are accommodated as C—H...N hydrogen‐bonded inversion‐symmetric dimers in the channel‐like voids of the host lattice. 相似文献
15.
Graham Smith Urs D. Wermuth Jonathan M. White 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(7):o464-o468
In the crystal structures of the proton‐transfer compounds of strychnine with 3,5‐dinitrosalicylic acid, namely strychninium 3,5‐dinitrosalicylate, C21H23N2O2+·C7H3N2O7−, (I), and 5‐nitrosalicylic acid, namely strychninium–5‐nitrosalicylate–5‐nitrosalicylic acid (1/1/2), C21H23N2O2+·C7H4NO5−·2C7H5NO5, (II), protonation of one of the N atoms of the strychnine molecule occurs and this group is subsequently involved in intermolecular hydrogen‐bonding interactions. In (I), this is four‐centred, the primary being with an adjacent strychninium carbonyl O‐atom acceptor in a side‐to‐side interaction giving linear chains. Other interactions are with the phenolate and nitro O‐atom acceptors of the anionic species, resulting in a one‐dimensional polymer structure. In (II), the N+—H interaction is three‐centred, the hydrogen bonding involving carboxyl O‐atom acceptors of the anion and both acid adduct species, giving unique discrete hetero‐tetramer units. The structure of (II) also features π‐bonding interactions between the two acid adduct molecules. 相似文献
16.
C. Foces‐Foces M. Lpez‐Rodríguez 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(12):o657-o660
2,6‐Bis(tert‐butyldimethylsilyloxy)‐9‐oxabicyclo[3.3.1]nonane‐3,7‐diol, C20H42O5Si2, (I), and 4,8‐bis(tert‐butyldimethylsilyloxy)‐2,6‐dioxatricyclo[3.3.13,7]decane‐1,3‐diol, C20H40O6Si2, (II), form layered structures that differ in the way the molecules are connected within each layer. The endocyclic O atom common to both structures plays an active role in the hydrogen‐bonding network, whereas the second oxygen bridge in (II) does not participate in any interaction. This work reports the first structural analysis of two bis(tert‐butyldimethylsilyloxy)‐substituted cyclic diol derivatives and provides insight into the influence of small changes in the molecular structure on the supramolecular aggregation. The unbalanced hydrogen‐bond acceptor/donor ratio, greater in (II) than in (I), does not result in the inclusion of water molecules in the structure. 相似文献
17.
Agata Biaoska Zbigniew Ciunik 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o853-o855
The crystal structures of brucine (2,3‐dimethoxystrychnidin‐10‐one), C23H26N2O4, brucine acetone solvate, C23H26N2O4·C3H6O, and brucine 2‐propanol solvate dihydrate, C23H26N2O4·C3H7O·2H2O, have been determined. Crystals of brucine and its 2‐propanol solvate dihydrate exhibit similar monolayer sheet packing, whereas crystals of the acetone solvate adopt a different mode of packing, as brucine pillars. The solvent appears to control the brucine self‐assembly on the basis of common donor–acceptor properties of the surfaces. 相似文献
18.
Hiroyuki Hosomi Shigeru Ohba Yoshikatsu Ito 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e147-e148
In the two title compounds, N‐methylcarbazole–3,5‐dinitrobenzonitrile (1/1), C13H11N·C7H3N3O4, (I), and N‐ethylcarbazole–3,5‐dinitrobenzonitrile (1/1), C14H13N·C7H3N3O4, (II), the donor and acceptor molecules are stacked alternately to form one‐dimensional columns. In (I), the N‐methyl group of the donor is nearly eclipsed with respect to one of the nitro groups of the neighboring acceptor in a column, whereas the N‐ethyl group is anti with respect to the cyano group of the neighboring acceptor in (II). 相似文献
19.
Chao Qin Xin‐Long Wang En‐Bo Wang 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(2):m73-m75
In the title compound, [Cd(C2O4)(C12H8N2)(C9H6O6)]·C6H5N3·H2O, the CdII atom has a distorted pentagonal–bipyramidal geometry, defined by two N atoms and five O atoms from bidentate 1,10‐phenanthroline ligands, oxalate ligands and benzene‐1,3,5‐tricarboxylic acid ligands. The oxalate ligands in the asymmetric unit possess inversion symmetry. The triazole molecule is not coordinated to the Cd atom. The structure of the title compound features a one‐dimensional chain running along the crystallographic a axis, and a three‐dimensional supramolecular network is formed via aromatic π–π interactions and hydrogen‐bonding interactions. 相似文献
20.
Mariko F. Matsuura Hyo-Joong Kim Daisuke Takahashi Khalil A. Abboud Steven A. Benner 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(12):952-959
Reported here is the crystal structure of a heterocycle that implements a donor–donor–acceptor hydrogen‐bonding pattern, as found in the Z component [6‐amino‐5‐nitropyridin‐2(1H)‐one] of an artificially expanded genetic information system (AEGIS). AEGIS is a new form of DNA from synthetic biology that has six replicable nucleotides, rather than the four found in natural DNA. Remarkably, Z crystallizes from water as a 1:1 complex of its neutral and deprotonated forms, and forms a `skinny' pyrimidine–pyrimidine pair in this structure. The pair resembles the known intercalated cytosine pair. The formation of the same pair in two different salts, namely poly[[aqua(μ6‐2‐amino‐6‐oxo‐3‐nitro‐1,6‐dihydropyridin‐1‐ido)sodium]–6‐amino‐5‐nitropyridin‐2(1H)‐one–water (1/1/1)], denoted Z‐Sod, {[Na(C5H4N3O3)(H2O)]·C5H5N3O3·H2O}n, and ammonium 2‐amino‐6‐oxo‐3‐nitro‐1,6‐dihydropyridin‐1‐ide–6‐amino‐5‐nitropyridin‐2(1H)‐one–water (1/1/1), denoted Z‐Am, NH4+·C5H4N3O3−·C5H5N3O3·H2O, under two different crystallization conditions suggests that the pair is especially stable. Implications of this structure for the use of this heterocycle in artificial DNA are discussed. 相似文献