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1.
R. Jagan D. Sathya K. Sivakumar 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(5):374-380
In the salt 1‐methylpiperazine‐1,4‐diium bis(dihydrogen phosphate), C5H13N22+·2H2PO4−, (I), and the solvated salt 2‐(pyridin‐2‐yl)pyridinium dihydrogen phosphate–orthophosphoric acid (1/1), C10H9N2+·H2PO4−·H3PO4, (II), the formation of O—H...O and N—H...O hydrogen bonds between the dihydrogen phosphate (H2PO4−) anions and the cations constructs a three‐ and two‐dimensional anionic–cationic network, respectively. In (I), the self‐assembly of H2PO4− anions forms a two‐dimensional pseudo‐honeycomb‐like supramolecular architecture along the (010) plane. 1‐Methylpiperazine‐1,4‐diium cations are trapped between the (010) anionic layers through three N—H...O hydrogen bonds. In solvated salt (II), the self‐assembly of H2PO4− anions forms a two‐dimensional supramolecular architecture with open channels projecting along the [001] direction. The 2‐(pyridin‐2‐yl)pyridinium cations are trapped between the open channels by N—H...O and C—H...O hydrogen bonds. From a study of previously reported structures, dihydrogen phosphate anions show a supramolecular flexibility depending on the nature of the cations. The dihydrogen phosphate anion may be suitable for the design of the host lattice for host–guest supramolecular systems. 相似文献
2.
Irena Matulkov Ivana Císaov Ivan Nmec Jan Fbry 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(10):927-933
The X‐ray single‐crystal structure determinations of the chemically related compounds 2‐amino‐1,3,4‐thiadiazolium hydrogen oxalate, C2H4N3S+·C2HO4−, (I), 2‐amino‐1,3,4‐thiadiazole–succinic acid (1/2), C2H3N3S·2C4H6O4, (II), 2‐amino‐1,3,4‐thiadiazole–glutaric acid (1/1), C2H3N3S·C5H8O4, (III), and 2‐amino‐1,3,4‐thiadiazole–adipic acid (1/1), C2H3N3S·C6H10O4, (IV), are reported and their hydrogen‐bonding patterns are compared. The hydrogen bonds are of the types N—H...O or O—H...N and are of moderate strength. In some cases, weak C—H...O interactions are also present. Compound (II) differs from the others not only in the molar ratio of base and acid (1:2), but also in its hydrogen‐bonding pattern, which is based on chain motifs. In (I), (III) and (IV), the most prominent feature is the presence of an R22(8) graph‐set motif formed by N—H...O and O—H...N hydrogen bonds, which are present in all structures except for (I), where only a pair of N—H...O hydrogen bonds is present, in agreement with the greater acidity of oxalic acid. There are nonbonding S...O interactions present in all four structures. The difference electron‐density maps show a lack of electron density about the S atom along the S...O vector. In all four structures, the carboxylic acid H atoms are present in a rare configuration with a C—C—O—H torsion angle of ∼0°. In the structures of (II)–(IV), the C—C—O—H torsion angle of the second carboxylic acid group has the more common value of ∼|180|°. The dicarboxylic acid molecules are situated on crystallographic inversion centres in (II). The Raman and IR spectra of the title compounds are presented and analysed. 相似文献
3.
Graham Smith Urs D. Wermuth 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(5):534-537
The structures of two ammonium salts of 3‐carboxy‐4‐hydroxybenzenesulfonic acid (5‐sulfosalicylic acid, 5‐SSA) have been determined at 200 K. In the 1:1 hydrated salt, ammonium 3‐carboxy‐4‐hydroxybenzenesulfonate monohydrate, NH4+·C7H5O6S−·H2O, (I), the 5‐SSA− monoanions give two types of head‐to‐tail laterally linked cyclic hydrogen‐bonding associations, both with graph‐set R44(20). The first involves both carboxylic acid O—H...Owater and water O—H...Osulfonate hydrogen bonds at one end, and ammonium N—H...Osulfonate and N—H...Ocarboxy hydrogen bonds at the other. The second association is centrosymmetric, with end linkages through water O—H...Osulfonate hydrogen bonds. These conjoined units form stacks down c and are extended into a three‐dimensional framework structure through N—H...O and water O—H...O hydrogen bonds to sulfonate O‐atom acceptors. Anhydrous triammonium 3‐carboxy‐4‐hydroxybenzenesulfonate 3‐carboxylato‐4‐hydroxybenzenesulfonate, 3NH4+·C7H4O6S2−·C7H5O6S−, (II), is unusual, having both dianionic 5‐SSA2− and monoanionic 5‐SSA− species. These are linked by a carboxylic acid O—H...O hydrogen bond and, together with the three ammonium cations (two on general sites and the third comprising two independent half‐cations lying on crystallographic twofold rotation axes), give a pseudo‐centrosymmetric asymmetric unit. Cation–anion hydrogen bonding within this layered unit involves a cyclic R33(8) association which, together with extensive peripheral N—H...O hydrogen bonding involving both sulfonate and carboxy/carboxylate acceptors, gives a three‐dimensional framework structure. This work further demonstrates the utility of the 5‐SSA− monoanion for the generation of stable hydrogen‐bonded crystalline materials, and provides the structure of a dianionic 5‐SSA2− species of which there are only a few examples in the crystallographic literature. 相似文献
4.
Graham Smith Urs D. Wermuth 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(8):738-741
The structures of two hydrated salts of 4‐aminophenylarsonic acid (p‐arsanilic acid), namely ammonium 4‐aminophenylarsonate monohydrate, NH4+·C6H7AsNO3−·H2O, (I), and the one‐dimensional coordination polymer catena‐poly[[(4‐aminophenylarsonato‐κO)diaquasodium]‐μ‐aqua], [Na(C6H7AsNO3)(H2O)3]n, (II), have been determined. In the structure of the ammonium salt, (I), the ammonium cations, arsonate anions and water molecules interact through inter‐species N—H...O and arsonate and water O—H...O hydrogen bonds, giving the common two‐dimensional layers lying parallel to (010). These layers are extended into three dimensions through bridging hydrogen‐bonding interactions involving the para‐amine group acting both as a donor and an acceptor. In the structure of the sodium salt, (II), the Na+ cation is coordinated by five O‐atom donors, one from a single monodentate arsonate ligand, two from monodentate water molecules and two from bridging water molecules, giving a very distorted square‐pyramidal coordination environment. The water bridges generate one‐dimensional chains extending along c and extensive interchain O—H...O and N—H...O hydrogen‐bonding interactions link these chains, giving an overall three‐dimensional structure. The two structures reported here are the first reported examples of salts of p‐arsanilic acid. 相似文献
5.
Linheng Wei Ziliang Wang Xianggao Meng 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(9):o453-o456
Cocrystallization of imidazole or 4‐methylimidazole with 2,2′‐dithiodibenzoic acid from methanol solution yields the title 2:1 and 1:1 organic salts, 2C3H5N2+·C14H10O4S22−, (I), and C4H7N2+·C14H10O4S2−, (II), respectively. Compound (I) crystallizes in the monoclinic C2/c space group with the mid‐point of the S—S bond lying on a twofold axis. The component ions in (I) are linked by intermolecular N—H...O hydrogen bonds to form a two‐dimensional network, which is further linked by C—H...O hydrogen bonds into a three‐dimensional network. In contrast, by means of N—H...O, N—H...S and O—H...O hydrogen bonds, the component ions in (II) are linked into a tape and adjacent tapes are further linked by π–π, C—H...O and C—H...π interactions, resulting in a three‐dimensional network. 相似文献
6.
Vladimir O. Gelmboldt Eduard V. Ganin Konstantin V. Domasevitch 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(9):o530-o534
In bis(2‐carboxypyridinium) hexafluorosilicate, 2C6H6NO2+·SiF62−, (I), and bis(2‐carboxyquinolinium) hexafluorosilicate dihydrate, 2C10H8NO2+·SiF62−·2H2O, (II), the Si atoms of the anions reside on crystallographic centres of inversion. Primary inter‐ion interactions in (I) occur via strong N—H...F and O—H...F hydrogen bonds, generating corrugated layers incorporating [SiF6]2− anions as four‐connected net nodes and organic cations as simple links in between. In (II), a set of strong N—H...F, O—H...O and O—H...F hydrogen bonds, involving water molecules, gives a three‐dimensional heterocoordinated rutile‐like framework that integrates [SiF6]2− anions as six‐connected and water molecules as three‐connected nodes. The carboxyl groups of the cation are hydrogen bonded to the water molecule [O...O = 2.5533 (13) Å], while the N—H group supports direct bonding to the anion [N...F = 2.7061 (12) Å]. 相似文献
7.
Ilia A. Guzei Frankline K. Keter Lara C. Spencer James Darkwa 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(8):o481-o483
Five distinct strong hydrogen‐bonding interactions of four kinds (N—H...Cl, N—H...O, O—H...N, and O—H...Cl) connect molecules of the title compound, C9H18N3+·Cl−·H2O, in the crystal structure into corrugated sheets stacked along the a axis. The intermolecular interactions are efficiently described in terms of the first‐ through fifth‐level graph sets. A two‐dimensional constructor graph helps visualize the supramolecular assembly. 相似文献
8.
Wilhelm Maximilian Hützler Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(1):93-100
In order to study the preferred hydrogen‐bonding pattern of 6‐amino‐2‐thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1‐methylpyrrolidin‐2‐one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures contain R21(6) N—H...O hydrogen‐bond motifs. In the latter four structures, additional R22(8) N—H...O hydrogen‐bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2‐thiouracil derivatives form homodimers stabilized by an R22(8) hydrogen‐bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds. 相似文献
9.
Ewa Matczak‐Jon Katarzyna
lepokura Pawe Kafarski Izabela Skrzyska Marek Jon 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(6):o261-o266
The crystal structures of two salts, products of the reactions between [(5‐methyl‐2‐pyridyl)aminomethylene]bis(phosphonic acid) and 4‐aminopyridine or ammonia, namely bis(4‐aminopyridinium) hydrogen [(5‐methyl‐2‐pyridinio)aminomethylene]diphosphonate 2.4‐hydrate, 2C5H7N2+·C7H10N2O6P22−·2.4H2O, (I), and triammonium hydrogen [(5‐methyl‐2‐pyridyl)aminomethylene]diphosphonate monohydrate, 3NH4+·C7H9N2O6P23−·H2O, (II), have been determined. In (I), the Z configuration of the ring N—C and amino N—H bonds of the bisphosphonate dianion with respect to the Cring—Namino bond is consistent with that of the parent zwitterion. Removing the H atom from the pyridyl N atom results in the opposite E configuration of the bisphosphonate trianion in (II). Compound (I) exhibits a three‐dimensional hydrogen‐bonded network, in which 4‐aminopyridinium cations and water molecules are joined to ribbons composed of anionic dimers linked by O—H...O and N—H...O hydrogen bonds. The supramolecular motif resulting from a combination of these three interactions is a common phenomenon in crystals of all of the Z‐isomeric zwitterions of 4‐ and 5‐substituted (2‐pyridylaminomethylene)bis(phosphonic acid)s studied to date. In (II), ammonium cations and water molecules are linked to chains of trianions, resulting in the formation of double layers. 相似文献
10.
P. Balamurugan R. Jagan K. Sivakumar 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(3):o109-o113
The title compounds, 2‐chloroanilinium dihydrogen phosphate (2CADHP) and 4‐chloroanilinium dihydrogen phosphate (4CADHP), both C6H7NCl+·H2PO4−, form two‐dimensional supramolecular organic–inorganic hybrid frameworks. In 2CADHP, the dihydrogen phosphate anions form a double‐stranded anionic chain generated parallel to the [010] direction through O—H...O hydrogen bonds, whereas in 4CADHP they form a two‐dimensional supramolecular net extending parallel to the crystallographic (001) plane into which the cations are linked through strong N—H...O hydrogen bonds. 相似文献
11.
Ming‐Yang He Zhi‐Hui Zhang Lu‐De Lu Xu‐Jie Yang Xin Wang 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(10):o525-o528
The title compounds, C10H10N22+·C8Cl4O42−·2H2O, (I), and 2C12H9N2+·C8Cl4O42−·C8H2Cl4O4·3H2O, (II), both crystallize as charge‐transfer organic salts with the dianionic or neutral acid components lying on inversion centres. The acid and base subunits in (I) arrange alternately to generate a linear tape motif via N—H...O hydrogen bonds; these tapes are further combined into a three‐dimensional architecture through multiple O—H...O and C—H...O interactions involving solvent water molecules. In contrast, the neutral and anionic acid components in (II) are linked to form a zigzag chain by means of O—H...O hydrogen bonds between acid groups, with dangling 1,10‐phenanthrolinium units connected to these chains by carboxylate–pyridinium interactions with R22(7) hydrogen‐bond notation. Adjacent chains are further extended to result in a two‐dimensional corrugated layer network viaπ–π interactions. Inter‐ion Cl...O interactions are also found in both (I) and (II). 相似文献
12.
Gene‐Hsiang Lee 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(5):o241-o244
The molecule of N,N′‐bis(4‐pyridylmethyl)oxalamide, C14H14N4O2, (I) or 4py‐ox, has an inversion center in the middle of the oxalamide group. Adjacent molecules are then linked through intermolecular N—H...N and C—H...O hydrogen bonds, forming an extended supramolecular network. 4,4′‐{[Oxalylbis(azanediyl)]dimethylene}dipyridinium dinitrate, C14H16N4O22+·2NO3−, (II), contains a diprotonated 4py‐ox cation and two nitrate counter‐anions. Each nitrate ion is hydrogen bonded to four 4py‐ox cations via intermolecular N—H...O and C—H...O interactions. Adjacent 4py‐ox cations are linked through weak C—H...O hydrogen bonding between an α‐pyridinium C atom and an oxalamide O atom, forming a two‐dimensional extended supramolecular network. 相似文献
13.
Graham Smith Urs D. Wermuth 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(7):o374-o380
The structures of the proton‐transfer compounds of 4,5‐dichlorophthalic acid (DCPA) with the aliphatic Lewis bases triethylamine, diethylamine, n‐butylamine and piperidine, namely triethylaminium 2‐carboxy‐4,5‐dichlorobenzoate, C6H16N+·C8H3Cl2O4−, (I), diethylaminium 2‐carboxy‐4,5‐dichlorobenzoate, C4H12N+·C8H3Cl2O4−, (II), bis(butanaminium) 4,5‐dichlorobenzene‐1,2‐dicarboxylate monohydrate, 2C4H12N+·C8H2Cl2O42−·H2O, (III), and bis(piperidinium) 4,5‐dichlorobenzene‐1,2‐dicarboxylate monohydrate, 2C5H12N+·C8H2Cl2O42−·H2O, (IV), have been determined at 200 K. All compounds have hydrogen‐bonding associations, giving discrete cation–anion units in (I) and linear chains in (II), while (III) and (IV) both have two‐dimensional structures. In (I), a discrete cation–anion unit is formed through an asymmetric R12(4) N+—H...O2 hydrogen‐bonding association, whereas in (II), chains are formed through linear N—H...O associations involving both aminium H‐atom donors. In compounds (III) and (IV), the primary N—H...O‐linked cation–anion units are extended into a two‐dimensional sheet structure via amide–carboxyl N—H...O and amide–carbonyl N—H...O interactions. In the 1:1 salts (I) and (II), the hydrogen 4,5‐dichlorophthalate anions are essentially planar with short intramolecular carboxyl–carboxyl O—H...O hydrogen bonds [O...O = 2.4223 (14) and 2.388 (2) Å, respectively]. This work provides a further example of the uncommon zero‐dimensional hydrogen‐bonded DCPA–Lewis base salt and the one‐dimensional chain structure type, while even with the hydrate structures of the 1:2 salts with the primary and secondary amines, the low dimensionality generally associated with 1:1 DCPA salts is also found. 相似文献
14.
Graham Smith 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(3):315-319
The structures of ammonium 3,5‐dinitrobenzoate, NH4+·C7H3N2O6−, (I), ammonium 4‐nitrobenzoate dihydrate, NH4+·C7H4NO4−·2H2O, (II), and ammonium 2,4‐dichlorobenzoate hemihydrate, NH4+·C7H3Cl2O2−·0.5H2O, (III), have been determined and their hydrogen‐bonded structures are described. All three salts form hydrogen‐bonded polymeric structures, viz. three‐dimensional in (I) and two‐dimensional in (II) and (III). With (I), a primary cation–anion cyclic association is formed [graph set R43(10)] through N—H...O hydrogen bonds, involving a carboxylate group with both O atoms contributing to the hydrogen bonds (denoted O,O′‐carboxylate) on one side and a carboxylate group with one O atom involved in two hydrogen bonds (denoted O‐carboxylate) on the other. Structure extension involves N—H...O hydrogen bonds to both carboxylate and nitro O‐atom acceptors. With structure (II), the primary inter‐species interactions and structure extension into layers lying parallel to (001) are through conjoined cyclic hydrogen‐bonding motifs, viz.R43(10) (one cation, an O,O′‐carboxylate group and two water molecules) and centrosymmetric R42(8) (two cations and two water molecules). The structure of (III) also has conjoined R43(10) and centrosymmetric R42(8) motifs in the layered structure but these differ in that the first motif involves one cation, an O,O′‐carboxylate group, an O‐carboxylate group and one water molecule, and the second motif involves two cations and two O‐carboxylate groups. The layers lie parallel to (100). The structures of salt hydrates (II) and (III), displaying two‐dimensional layered arrays through conjoined hydrogen‐bonded nets, provide further illustration of a previously indicated trend among ammonium salts of carboxylic acids, but the anhydrous three‐dimensional structure of (I) is inconsistent with that trend. 相似文献
15.
Jun‐Fang Guo Bing‐Xin Guo Jiang‐Yu Wu Guo‐Ping Yan 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(7):742-744
A novel supramolecular framework, catena‐poly[[[aqua(2‐phenylquinoline‐4‐carboxylato‐κO)silver(I)]‐μ‐4,4′‐bipyridine‐κ2N:N′] dihydrate], {[Ag(C16H10NO2)(C10H8N2)(H2O)]·2H2O}n, has been synthesized and structurally characterized. The AgI centres are four‐coordinated and bridged by 4,4′‐bipyridine (4,4′‐bipy) ligands to form a one‐dimensional Ag–bipy chain. The Ag–bipy chains are further linked together by intermolecular O—H...O and O—H...N hydrogen‐bonding interactions between adjacent chains, resulting in a three‐dimensional framework. 相似文献
16.
Christian Neis Bernd Morgenstern Kaspar Hegetschweiler 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(1):28-34
A first preliminary report on the crystal structure of a hydrated salt formulated as [Ge(taci)2]Cl4·13H2O (taci is 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol) appeared more than 20 years ago [Ghisletta (1994). PhD thesis, ETH Zürich. Switzerland]. At that time it was not possible to discriminate unambiguously between the positions of some of the chloride ions and water O atoms, and disorder was thus postulated. In a new determination, a conclusive scheme of hydrogen bonding proves to be a particularly appealing aspect of the structure. Single crystals of the title compound, C12H30GeN6O64+·4Cl−·6H2O or [Ge(taci)2]2Cl8·12H2O, were grown from an aqueous solution by slow evaporation of the solvent. The two [Ge(taci)2]4+ cations exhibit a double‐adamantane‐type structure with exclusive O‐atom coordination and approximate D3d symmetry. The taci ligands adopt a zwitterionic form with deprotonated hydroxy groups and protonated amino groups. Both cations are hydrogen bonded to six water molecules. The structure of the hydration shell of the two cations is, however, slightly different. The {[Ge(taci)2]·6H2O}4+ aggregates are interlinked in all three dimensions by further hydrogen bonds of the types N—H...Cl...H—N, N—H...O(H)2...H—N, (Ge)O...H—O(H)...H—N, N—H...O(H)—H...Cl...H—N, (Ge)O...H—O—H...Cl...H—N, N—H...O(H)—H...Cl...H—(H)O...H—N, (Ge)O...H—O—H...Cl...H—(H)O...H—N and Ge(O)...H—O—H...Cl...H—O—H...O(Ge). 相似文献
17.
Rafal Kruszynski Agata Trzesowska‐Kruszynska 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(12):o624-o629
The 2‐aminobenzothiazole sulfonation intermediate 2,3‐dihydro‐1,3‐benzothiazol‐2‐iminium monohydrogen sulfate, C7H7N2S+·HSO4−, (I), and the final product 2‐iminio‐2,3‐dihydro‐1,3‐benzothiazole‐6‐sulfonate, C7H6N2O3S2, (II), both have the endocyclic N atom protonated; compound (I) exists as an ion pair and (II) forms a zwitterion. Intermolecular N—H...O and O—H...O hydrogen bonds are seen in both structures, with bonding energy (calculated on the basis of density functional theory) ranging from 1.06 to 14.15 kcal mol−1. Hydrogen bonding in (I) and (II) creates DDDD and C(8)C(9)C(9) first‐level graph sets, respectively. Face‐to‐face stacking interactions are observed in both (I) and (II), but they are extremely weak. 相似文献
18.
Zhi‐Hui Zhang Jin‐Long Wang Ning Gao Ming‐Yang He 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(7):668-671
The novel title organic salt, 4C5H7N2+·C24H8O84−·8H2O, was obtained from the reaction of perylene‐3,4,9,10‐tetracarboxylic acid (H4ptca) with 4‐aminopyridine (4‐ap). The asymmetric unit contains half a perylene‐3,4,9,10‐tetracarboxylate (ptca4−) anion with twofold symmetry, two 4‐aminopyridinium (4‐Hap+) cations and four water molecules. Strong N—H...O hydrogen bonds connect each ptca4− anion with four 4‐Hap+ cations to form a one‐dimensional linear chain along the [010] direction, decorated by additional 4‐Hap+ cations attached by weak N—H...O hydrogen bonds to the ptca4− anions. Intermolecular O—H...O interactions of water molecules with ptca4− and 4‐Hap+ ions complete the three‐dimensional hydrogen‐bonding network. From the viewpoint of topology, each ptca4− anion acts as a 16‐connected node by hydrogen bonding to six 4‐Hap+ cations and ten water molecules to yield a highly connected hydrogen‐bonding framework. π–π interactions between 4‐Hap+ cations, and between 4‐Hap+ cations and ptca4− anions, further stabilize the three‐dimensional hydrogen‐bonding network. 相似文献
19.
Ammasai Karthikeyan Robert Swinton Darious Packianathan Thomas Muthiah Franc Perdih 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(11):985-990
Two novel cocrystals of the N(7)—H tautomeric form of N6‐benzoyladenine (BA), namely N6‐benzoyladenine–3‐hydroxypyridinium‐2‐carboxylate (3HPA) (1/1), C12H9N5O·C6H5NO3, (I), and N6‐benzoyladenine–DL‐tartaric acid (TA) (1/1), C12H9N5O·C4H6O6, (II), are reported. In both cocrystals, the N6‐benzoyladenine molecule exists as the N(7)—H tautomer, and this tautomeric form is stabilized by intramolecular N—H...O hydrogen bonding between the benzoyl C=O group and the N(7)—H hydrogen on the Hoogsteen site of the purine ring, forming an S(7) motif. The dihedral angle between the adenine and phenyl planes is 0.94 (8)° in (I) and 9.77 (8)° in (II). In (I), the Watson–Crick face of BA (N6—H and N1; purine numbering) interacts with the carboxylate and phenol groups of 3HPA through N—H...O and O—H...N hydrogen bonds, generating a ring‐motif heterosynthon [graph set R22(6)]. However, in (II), the Hoogsteen face of BA (benzoyl O atom and N7; purine numbering) interacts with TA (hydroxy and carbonyl O atoms) through N—H...O and O—H...O hydrogen bonds, generating a different heterosynthon [graph set R22(4)]. Both crystal structures are further stabilized by π–π stacking interactions. 相似文献
20.
Maya Tutughamiarso Ernst Egert 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(11):o439-o445
In order to investigate the relative stability of N—H...O and N—H...S hydrogen bonds, we cocrystallized the antithyroid drug 6‐propyl‐2‐thiouracil with two complementary heterocycles. In the cocrystal pyrimidin‐2‐amine–6‐propyl‐2‐thiouracil (1/2), C4H5N3·2C7H10N2OS, (I), the `base pair' is connected by one N—H...S and one N—H...N hydrogen bond. Homodimers of 6‐propyl‐2‐thiouracil linked by two N—H...S hydrogen bonds are observed in the cocrystal N‐(6‐acetamidopyridin‐2‐yl)acetamide–6‐propyl‐2‐thiouracil (1/2), C9H11N3O2·2C7H10N2OS, (II). The crystal structure of 6‐propyl‐2‐thiouracil itself, C7H10N2OS, (III), is stabilized by pairwise N—H...O and N—H...S hydrogen bonds. In all three structures, N—H...S hydrogen bonds occur only within R22(8) patterns, whereas N—H...O hydrogen bonds tend to connect the homo‐ and heterodimers into extended networks. In agreement with related structures, the hydrogen‐bonding capability of C=O and C=S groups seems to be comparable. 相似文献