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Two series of a total of ten cocrystals involving 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine with various carboxylic acids have been prepared and characterized by single‐crystal X‐ray diffraction. The pyrimidine unit used for the cocrystals offers two ring N atoms (positions N1 and N3) as proton‐accepting sites. Depending upon the site of protonation, two types of cations are possible [Rajam et al. (2017). Acta Cryst. C73, 862–868]. In a parallel arrangement, two series of cocrystals are possible depending upon the hydrogen bonding of the carboxyl group with position N1 or N3. In one series of cocrystals, i.e. 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–3‐bromothiophene‐2‐carboxylic acid (1/1), 1, 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–5‐chlorothiophene‐2‐carboxylic acid (1/1), 2, 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–2,4‐dichlorobenzoic acid (1/1), 3, and 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–2‐aminobenzoic acid (1/1), 4, the carboxyl hydroxy group (–OH) is hydrogen bonded to position N1 (O—H…N1) of the corresponding pyrimidine unit (single point supramolecular synthon). The inversion‐related stacked pyrimidines are doubly bridged by the carboxyl groups via N—H…O and O—H…N hydrogen bonds to form a large cage‐like tetrameric unit with an R42(20) graph‐set ring motif. These tetrameric units are further connected via base pairing through a pair of N—H…N hydrogen bonds, generating R22(8) motifs (supramolecular homosynthon). In the other series of cocrystals, i.e. 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–5‐methylthiophene‐2‐carboxylic acid (1/1), 5, 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–benzoic acid (1/1), 6, 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–2‐methylbenzoic acid (1/1), 7, 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–3‐methylbenzoic acid (1/1), 8, 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–4‐methylbenzoic acid (1/1), 9, and 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–4‐aminobenzoic acid (1/1), 10, the carboxyl group interacts with position N3 and the adjacent 4‐amino group of the corresponding pyrimidine ring via O—H…N and N—H…O hydrogen bonds to generate the robust R22(8) supramolecular heterosynthon. These heterosynthons are further connected by N—H…N hydrogen‐bond interactions in a linear fashion to form a chain‐like arrangement. In cocrystal 1, a Br…Br halogen bond is present, in cocrystals 2 and 3, Cl…Cl halogen bonds are present, and in cocrystals 5, 6 and 7, Cl…O halogen bonds are present. In all of the ten cocrystals, π–π stacking interactions are observed. [ABSTRACT FROM AUTHOR]

The crystals of two new salts, 2,6-diamino-4-chloropyrimidin-1-ium 5-chlorosalicylate, C4H6ClN4 +.C7H4ClO3 -, (I), and bis(2,6-diamino-4-chloropyrimidin-1- ium) naphthalene-1,5-di-sulfonate, 2C4H6ClN4 +.C10H6O6S2 2-, (II), have been synthesized and characterized by single-crystal X-ray diffraction. In both compounds, the N atom of the pyrimidine group in between the amino substituents is protonated and the pyrimidinium cation forms a pair of N-- H. . .O hydrogen bonds with the carboxylate/sulfonate ion, leading to a robust R2 2(8) motif (supramolecular heterosynthon). In compound (I), a selfcomplementary base pairing involving the other pyrimidinium ring nitrogen atom and one of the amino groups via a pair of N--H. . .N hydrogen bonds [R2 ²(8) homosynthon] is also present. In compound (II), the crystallographic inversion centre coincides with the inversion centre of the naphthalene-1,5- disulfonate ion and all the sulfonate O atoms are hydrogen-bond acceptors, generating fused-ring motifs and a quadruple DDAA array. A halogen-bond (Cl. . .Cl) interaction is present in (I) with a distance and angle of 3.3505 (12) Å and 151.37 (10)°, respectively. In addition, a C--Cl. . .π interaction and a π-π interaction in (I) and a π-π interaction in (II) further stabilize these crystal structures. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title co-crystal, C12H9N5O·C7H6O3, contains one molecule of N6-benzoyladenine (BA) and one molecule of 4-hydroxybenzoic acid (HBA). The N6-benzoyladenine (BA) has an N(7)--H tautomeric form with nonprotonated N-1 and N-3 atoms. This tautomeric form is stabilized by a typical intramolecular N--H⋯O hydrogen bond between the carbonyl (C＝O) group and the N(7)--H hydrogen on the Hoogsteen face of the purine ring, forming a graph-set S(7) ring motif. The primary robust R²2(8) ring motif is formed in the Watson-Crick face via N--H⋯O and O--H⋯N hydrogen bonds (involving N1, N6--H and the carboxyl group of HBA).Weak interactions, such as, C--H⋯π and π-π are also observed in this crystal structure. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, 5-fluorocytosinium picrate, C4H5FN3O+·C6H2N3O7-, one N heteroatom of the 5-fluorocytosine (5FC) ring is protonated. The 5FC ring forms a dihedral angle of 19.97 (11)° with the ring of the picrate (PA-) anion. In the crystal, the 5FC+ cation interacts with the PA- anion through three-centre N--H⋯O hydrogen bonds, forming two conjoined rings having R2¹(6) and R1²(6) motifs, and is extended by N--H⋯O hydrogen bonds and C--H⋯O interactions into a two-dimensional sheet structure lying parallel to (001). Also present in the crystal structure are weak C--F⋯π interactions. [ABSTRACT FROM AUTHOR]

The design of a pharmaceutical cocrystal is based on the identification of specific hydrogen-bond donor and acceptor groups in active pharmaceutical ingredients (APIs) in order to choose a `complementary interacting' molecule that can act as an efficient coformer. 5-Fluorouracil (5FU) is a pyrimidine derivative with two N-H donors and C=O acceptors and shows a diversity of hydrogen-bonding motifs. Two 1:1 cocrystals of 5-fluorouracil (5FU), namely 5-fluorouracil-4-methylbenzoic acid (5FU-MBA), C4H3FN2O2·C8H8O2, (I), and 5-fluorouracil-3-nitrobenzoic acid (5FU-NBA), C4H3FN2O2·C7H5NO4, (II), have been prepared and characterized by single-crystal X-ray diffraction. In (I), the MBA molecules form carboxylic acid dimers [ R22(8) homosynthon]. Similarly, the 5FU molecules form two types of base pair via a pair of N-H...O hydrogen bonds [ R22(8) homosynthon]. In (II), 5FU interacts with the carboxylic acid group of NBA via N-H...O and O-H...O hydrogen bonds, generating an R22(8) ring motif (heterosynthon). Furthermore, the 5FU molecules form base pairs [ R22(8) homosynthon] via N-H...O hydrogen bonds. Both of the crystal structures are stabilized by C-H...F interactions. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, 2C5H3ClO2S·C10H8N2, is comprised of a molecule of 3-chlorothiophene-2-carboxylic acid (3TPC) and half of a molecule of 4,4′-bipyridine (BPY). A distinctive O--H′N-based synthon is present. Cl′Cl and π-π stacking interactions further stabilize the crystal structure, forming a two-dimensional network parallel to the bc plane. [ABSTRACT FROM AUTHOR]

In the title salt, C6H9ClN3+·C6H3O4S-, the cations and anions are linked via O-H⋯O and N-H⋯O hydrogen bonds, forming R66(37) ring motifs that are inter?connected with each other, producing sheets. Separate parallel inversion-related sheets are linked through N-H⋯N and [pi]-[pi] stacking inter?actions [centroid-centroid distance = 3.5414 (13) Å], forming double layers parallel to (101). Weak C-H⋯O and C-H⋯S hydrogen bonds, as well as C-H⋯π inter?actions, connect the double layers into a three-dimensional network. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title co-crystal, C12H9N5O0.5C6H10O4, consists of one molecule of N6-benzoyladenine (BA) and one half-molecule of adipic acid (AA), the other half being generated by inversion symmetry. The dihedral angle between the adenine and phenyl ring planes is 26.71 (7)°. The N6-benzoyladenine molecule crystallizes in the N(7)--H tautomeric form with three non-pro tonated N atoms. This tautomeric form is stabilized by intramolecular N--H⋯O hydrogen bonding between the carbonyl (CO) group and the N(7)--H hydrogen atom on the Hoogsteen face of the purine ring, forming an S(7) ring motif. The two carboxyl groups of adipic acid interact with the Watson-Crick face of the BA molecules through O--H⋯N and N--H⋯O hydrogen bonds, generating an R2²(8) ring motif. The latter units are linked by N--H⋯N hydrogen bonds, forming layers parallel to (105. A weak C--H⋯O hydrogen bond is also present, linking adipic acid molecules in neighbouring layers, enclosing R²2(10) ring motifs and forming a three-dimensional structure. C=O⋯π and C--H⋯π interactions are also present in the structure. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, 4C4H4FN3O•C3H6N6, comprises of two independent 5-fluoro-cytosine (5FC) molecules (A and B) and one half-molecule of melamine (M). The other half of the melamine molecule is generated by a twofold axis. 5FC molecules A and B are linked through two different homosynthons [R2² (8) ring motif]; one is formed via a pair of N--H⋯O hydrogen bonds and the second via a pair of N--H⋯N hydrogen bonds. In addition to this pairing, the O atoms of 5FC molecules A and B inter-act with the N2 amino group on both sides of the melamine molecule, forming a DDAA array of quadruple hydrogen bonds and generating a supramolecular pattern. The 5FC (molecules A and B) and two melamine molecules interact via N--H⋯O, N--H⋯N and N--H⋯O, N--H⋯N, C--H⋯F hydrogen bonds forming R66(24) and R44(15) ring motifs. The crystal structure is further strengthened by C--H⋯F, C--F⋯π and π--π stacking interactions. [ABSTRACT FROM AUTHOR]

Background Design of new metal complexes is an interesting field for development of new functional molecular based materials. In this process by the usage of mixed functional ligands one can precisely tune the physical and chemical properties of those metal complexes. However, it is difficult to obtain the desired complex in many cases for factors like different coordination abilities of the ligands and the types of anions have a great influence on the structure. Results A series of five copper(II) complexes [Cu(Bipy) (5-TPC) 2(H2O)] (1), [Cu(Phen) (5-TPC) 2(H2O)] (2), [Cu(NO3) (4,7-Phen) (5-TPC) (H2O)].H2O (3), [Cu(Bipy) 2(5-TPC)]2.(ClO4)2 (4), and [Cu2(Bipy)4(H2PO4)] (5) (where Bipy = 2,2'-bipyridine, Phen = 1,10-phenanthroline, 4,7-Phen = 4,7-hydroxy-1,10-phenanthroline, 5-TPC = 5-chloro-2 thiophene carboxylate) has been synthesized and characterised using single crystal X-ray diffraction studies. In all the compounds, the N,N' ligand coordinates in a bidentate chelating manner and the copper has a square pyramidal geometry. Conclusions Complexes (1,2) are expected to be isostructural due to similarity of the N.N'-chelating ligands used, but due to the difference in supramolecular architectures no similar unit cells were observed. This is important in crystal engineering point of view. Complexes (1-4) possess the neutral mononuclear and complex (5) possesses a dinuclear entity. These entities are connected by intermolecular interactions like X...π, H...X, (X = Cl) generating supramolecular architectures. [ABSTRACT FROM AUTHOR]

Background The usage of polynuclear metal clusters as secondary building units (SBU's) in designing of metal organic frameworks (MOF's) is a field of current interest. These metal clusters have attracted a great deal of attention not only due to their interesting structural topologies but also due to promising physical and chemical properties. In this regard various d,f block (transition and lanthanide) metal clusters have been widely investigated so far. Less attention is paid to construction of heavy p-block Pb(II) clusters. Results Two mixed ligand Pb(II) clusters have been synthesized with bipy(2,2'-Bipyridine), phen(1,10-Phenanthroline), quin (8-Hydroxy quinolinate) and 5-tpc (5-chloro thiophene 2- carboxylate). They have been characterized by elemental analysis, IR, TGA and X-ray crystallography. X-ray diffraction analysis reveals that the complexes [Pb4(quin)4(bipy)2(5- tpc)4] (1) and [Pb4(quin) 4(phen) 2(5-tpc)4] (2) are tetranuclear. The complexes show a slight variation in unit cell parameters, due to the replacement of bipy and the phen ligands. Both complexes contain two types of Pb(II) ions which differ in the coordination geometry around the Pb(II) ion. Conclusions In both complexes the four lead ions Pb1,Pb2, Pb1i and Pb2i lie on the same plane bridged by the 5-tpc anions. Pb1 and Pb2 of both complexes contain a 5-tpc and quin coordinated in a bidentate chelating bridging fashion. In addition the Pb2 and Pb2i ions alone contain a bipy and phen in a bidentate chelating fashion in (1) and (2) respectively. An additional notable feature in both of these complexes are the bridging ability of the quin oxygen which forms a network of coordination bonds in between the four Pb(II) ions. In both complexes the individual units are self-assembled by C-H---Cl/C-H---S hydrogen bonding interactions to generate 2-D aggregates. [ABSTRACT FROM AUTHOR]

Highlights: [•] Uranyl complexes (1 and 2) with 5-TPC and bipyridyl ligands are mononuclear. [•] Uranyl complexes (1 and 2) with 5-TPC and bipyridyl ligands are isostructural. [•] Uranyl complex (3) is a coordination polymer. [•] Structure (2) form supramolecular architectures via hydrogen-bridged networks and halogen bonds. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hydrates of alkaline earth metal complexes with 5-TPC and Phen ligands are binuclear. [•] Hydrates of alkaline earth metal complexes with 5-TPC and Phen ligands are isomorphous. [•] Transition metal complexes of divalent Mn and Pd with these ligands are mononuclear. [•] These hydrate structures form supramolecular architectures via a hydrogen-bridged network. [Copyright &y& Elsevier]

The two centrosymmetric dinuclear copper paddle-wheel complexes tetrakis(μ-4-hydroxybenzoato-κ2 O: O′)bis[aquacopper(II)] dimethylformamide disolvate dihydrate, [Cu2(C7H5O3)4(H2O)2]·2C3H7NO·2H2O, (I), and tetrakis(μ-4-methoxybenzoato-κ2 O: O′)bis[(dimethylformamide-κ O)copper(II)], [Cu2(C8H7O3)4(C3H7NO)2], (II), crystallize with half of the dinuclear paddle-wheel cage unit in the asymmetric unit and, in addition, complex (I) has one dimethylformamide (DMF) and one water solvent molecule in the asymmetric unit. In both (I) and (II), two CuII ions are bridged by four syn, syn-η1:η1:μ carboxylate groups, showing a paddle-wheel cage-type structure with a square-pyramidal coordination geometry. The equatorial positions of (I) and (II) are occupied by the carboxylate groups of 4-hydroxy- and 4-methoxybenzoate ligands, and the axial positions are occupied by aqua and DMF ligands, respectively. The three-dimensional supramolecular metal-organic framework of (I) consists of three different R22(20) and an R44(36) ring motif formed via O-H...O and O W-H W...O hydrogen bonds. Complex (II) simply packs as molecular species. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two paddle wheel typed two Cu(II) complexes have been synthesized. [•] The complexes have been characterized by IR, EPR and X-ray diffraction studies. [•] It is interesting that complexes (1) and (2) differ in the axial coordinated solvent. [•] Influences of the axial solvents on supramolecular architectures are investigated. [Copyright &y& Elsevier]

Background: Lead is a heavy toxic metal element in biological systems and is one of the major pollutants as a result of its widespread use in industries. In spite of its negative roles the coordination chemistry of Pb(II) complexes is a matter of interest. The N,N'-bidentate aromatic bases such as BPY,4-BPY and PHEN (BPY = 2,2'bipyridine, 4-BPY = 4,4'-dimethyl-2,2'-bipyridine, PHEN = 1,10-Phenanthroline) are widely used to build supramolecular architectures because of their excellent coordinating ability and large conjugated system that can easily form π-π interactions among their aromatic moieties. A series of novel Pb(II) complexes in concert with 5-CTPC, 5-BTPC (5-CTPC = 5-chlorothiophen-2-carboxylate, 5-BTPC = 5-bromothiophen-2-carboxylate) and corresponding bidentate chelating N.N' ligands have been synthesized and characterized. Results: Five new Pb (II) complexes [Pb(BPY)(5-CTPC)2] (1), [Pb(4-BPY)(5-CTPC)2] (2), [Pb2(PHEN)2(5-CTPC)4] (3), [Pb(4-BPY)(5-BTPC)2] (4) and [Pb2(PHEN)2(5-BTPC)2(ACE)2] (5) have been synthesized. Even though in all these complexes the molar ratio of Pb, carboxylate, N,N-chelating ligand are the same (1:2:1), there is a significant structural diversity. These complexes have been characterised and investigated by elemental analysis, IR, 1H-NMR,13C-NMR, TGA, and photoluminescence studies. Single crystal X-ray diffraction studies reveal that complexes (1, 2) and (4) are mononuclear while (3 and 5) are dinuclear in nature which may result from the chelating nature of the ligands, various coordination modes of the carboxylates, and the coordination geometry of the Pb(II) ions. Conclusions: The observation of structures 2,4 and 3,5 show the structural changes made just chloro/bromo substituent of the thiophene ring. A detailed packing analysis has been undertaken to delineate the role of valuable non covalent interactions like X...π, H...X, (X = Cl/Br). A quadruple hydrogen bond linking the monomeric units and generating a supramolecular architecture is observed in (1). The metal bite unit comprised of PbN2C2 (i.e. Pb-N-C-C-N-Pb) is the repeating unit in all the five complexes and they have almost same geometrical parameters. This metal bite has been identified as the self assembly unit in complexes. [ABSTRACT FROM AUTHOR]

Background: Various dinuclear copper (II) complexes with octahedral geometry have been reported. The majority of these complexes contain N containing aromatic rings as axial ligands. There are also a few cases where the solvent used in the reaction occupies the axial position of the dinuclear copper (II) complex. This may occur by planned synthesis or some times by serendipity. Here we report some four copper (II) complexes containing solvent and or N containing heterocyclic ring as the axial ligand. Results: Four compounds, each containing dinuclear Copper (II) units (with the most robust, frequently occurring paddle wheel structures) were synthesized and characterised by single crystal X-ray diffraction and by IR spectroscopy. The compounds 1 & 2 have the general formula Cu2(RCOO) 4 (L) 2 [(for (1) RCOO= 4-Chloro Benzoate, L= Isopropanol; for 2 RCOO= Benzoate, L= 2-Amino-4,6-dimethyl pyrimidine )] while 3 & 4 have the general formula, Cu2 (RCOO) 4 (S) 2 Cu2 (RCOO) 4 (L) 2 [RCOO=5-Chloro-thiophene-2-carboxylate L= 2-Amino-4,6-dimethyl pyrimidine, for 3 S= ethanol; for 4 S= methanol ]. A wide range of hydrogen bonds (of the O-H...O, N-H...O and N-H...N type) and p-p stacking interactions are present in the crystal structures. Conclusions: All compounds contain the dinuclear units, in which two Cu (II) ions are bridged by four syn, syn-η¹ η¹ µ carboxylates, showing a paddle-wheel cage type with a distorted octahedral geometry. The compounds 1 & 2 contain a single dimeric unit while 3 & 4 contain two dimeric units. The structures 3 and 4 are very interesting co-crystals of two paddle wheel molecules. Also it is interesting to note that the compounds 3 & 4 are isostructural with similar cell parameters. Both the compounds 3 & 4 differ in the solvent molecule coordinated to copper in one of the dimeric units. In all the four compounds, each of the copper dimers has an inversion centre. Every copper has a distorted octahedral centre, formed by four oxygen atoms (from different carboxylate) in the equatorial sites. The two axial positions are occupied by copper and the corresponding ligand. [ABSTRACT FROM AUTHOR]

Abstract: In the present study 1,2-bis(4-pyridyl)ethane (BPA) crystallizes with 2-chlorobenzoic acid (2CBA), 4-methylbenzoic acid (4MBA), phthalic acid (PA), succinic acid (SA) and adipic acid (AA) to yield co-crystals BPA.2CBA (1), BPA.4MBA (2), BPA.PA (3), BPA.SA (4) and BPA.AA (5) respectively. All the five co-crystals are constituted by the utilization of the (7) synthon, created by the combination of hard N-H⋯O and complementary soft C–H⋯O hydrogen bonds. 1 and 2 illustrate the formation of three component aggregate as in both cases BPA interacts with carboxylic acids to form supramolecular ladder-type assembies. Molecular recognition in co-crystals 3–5 results in the formation of extended infinite tapes and differ further as a consequence of the soft C–H⋯O bonds and stacking interactions. Structure 3 shows the formation of zig-zag tapes while 4 and 5 form linear infinite tapes. Structure 4 shows isostructural behaviour with an analogous structure previously reported (Bowes et al. (2003) ).The isostructurality is because of the structural resemblance between both the entities in the co-crystals – fumaric acid/succinic acid and 1,2-bis(4-pyridyl)ethane/1,2-bis(4-pyridyl)ethene. Compound 5 shows good degree of resemblance with another reported analogous structure-1,2-bis(4-pyridyl)ethene adipic acid. (Zhang et al. (2003) ). Structure 5 and the reported structure form similar supramolecular sheets through intertape interactions differing from each other only in the alignment of neighboring tapes. The linear tapes in both the cases are linked laterally through different C–H⋯O interactions and ventrally through different stacking interactions. This work illustrates the construction of different supramolecular architectures and the role of weak C–H⋯O hydrogen bonds and stacking interactions in the higher level of supramolecular organization. [Copyright &y& Elsevier]

The article describes the crystal structures of the compounds hemi(4,4'-bipyridinium) tris(5-chiorothiophene-2-carboxylato)dioxidouranate(VI) monohydrate and hemi[4,4'-(ethane-l,2-diyl)dipyridin-ium] tris(5-chlorothiophene-2-carboxylato)dioxidouranate(VI) monohydrate. The metal centres are connected by classical O--H-.O and N--H.O hydrogen bonds involving the coordinated ligands, the diprotonated organic linker cation and water molecules. The crystal structures are further supported by weak C--H.O and π-π stacking interactions.

In the crystal structure of the title compound, 2C6H9N3 C8H6O4, terephthalic acid has a crystallographic inversion centre and the dimethylpyrimidine molecule shows approximate non-crystallographic mirror and twofold rotation symmetry. The inversion-related pyrimidine molecules form a base pair [R2 2(8) ring motif] via a pair of NH⋯N hydrogen bonds. The carboxyl groups of terephthalic acid link the base pairs via OH⋯N and NH⋯O hydrogen bonds [R2 2(8) motif] to generate a supramolecular ribbon. [ABSTRACT FROM AUTHOR]

In the title compound, 2C14H19N4O3+·C7H3NO42−·5H2O, the asymmetric unit contains two trimethoprim cations ( A and B), a dipicolinate anion and five water mol­ecules. One of the picolinate carboxyl­ate groups inter­acts with cation A via a pair of N—H⋯O hydrogen bonds, forming a ring motif (8). A loop of O—H⋯O hydrogen bonds is formed between four water mol­ecules and the two carboxyl­ate groups to form a supramolecular chain along the a axis. Mol­ecules A and B constitute a base pair via N—H⋯N hydrogen bonds, and these base pairs are cross-linked by N—H⋯O and C—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

The article discusses the crystal structure of the metal-organic compound, Triaqua(µ-7-iodo-8-oxidoquinoline-5-sulfonato-k2N,O8)dioxidouranium(VI) dihydrate. It mentions that the compound's asymmetric unit has two uncoordinated water molecules, among others. The crystal structures of the copper complexes of the 8-hydroxy-7-iodoquinoline-5-sulfonic acid (HQS) are also examined.

In the title structure, C6H10N3+·C6H2N3O7-, the asymmetric unit consists of a 2-amino-4,6-dimethylpyrimidinium cation and a picrate (2,4,6-trinitrophenolate) anion. In the crystal structure, inversion-symmetry-related cations are paired via N—H…N hydrogen bonds, whereas inversion-related anions are paired via weak C—H…O hydrogen bonds. The cations and anions further interact with each other through N—H…O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, 2,4-diamino-5-(4-chloro­phen­yl)-6-ethyl­pyrimidin-1-ium 3-carb­oxy-4-hydroxy­benzene­sulfonate monohydrate, C12H14ClN4+·C7H5O6S−·H2O, the asymmetric unit contains two crystallographically independent protonated pyrimethamine (PMN) mol­ecules, a pair of sulfosalicylate anions and two water mol­ecules. Both the PMN molecules are protonated at one of the pyrimidine N atoms. The component species inter­act through numerous inter­molecular N—H⋯O, N—H⋯N and O—H⋯O hydrogen bonds and C—H⋯O inter­actions. [ABSTRACT FROM AUTHOR]

In the title complex, [Ni(NCS)2(H2O)4]·4C6H9N3·2H2O, the nickel(II) ion occupies an inversion centre and is octahedrally coordinated by two N-bonded thio­cyanate ions and four water mol­ecules. The two distinct 2-amino-4,6-di­methyl­pyrimidine mol­ecules adopt distinct base-pairing dimerization patterns via different pairs of N—H⋯N bonds. They are also hydrogen bonded to the coordinated and uncoordinated water mol­ecules and thio­cyanate ions through O—H⋯O, O—H⋯S(thio­cyanate) and N—H⋯N(thio­cyanate) hydrogen bonds. [ABSTRACT FROM AUTHOR]

The title complex, {[Cd(NCS)2(H2O)2]·2C6H9N3} n, crystalizes in the triclinic space group P . The asymmetric unit contains one 2-amino-4,6-di­methyl­pyrimidine mol­ecule, a thio­cyanate ion, a water mol­ecule and a cadmium ion (site symmetry ). The cadmium ions are symmetrically doubly bridged by thio­cyanate ions, leading to a polymeric chain motif. The octahedral coordination geometry of cadmium is completed by a pair of inversion-related water mol­ecules. The 2-amino­pyrimidine mol­ecules are not coordinated to cadmium but are hydrogen-bonded to the coordinated water mol­ecules and thio­cyanate ions. There is also a pyrimidine–pyrimidine interaction via an N—H⋯N hydrogen bond. [ABSTRACT FROM AUTHOR]

In the title compound, 2,4-di­amino-5-(3,4,5-tri­methoxy­benzyl)­pyrimidinium hydrogen malonate, C14H19N4O3+·C3H3O4−, the trimethoprim mol­ecule is protonated at one of the pyrimidine N atoms. The carboxyl­ate group of the hydrogen malonate ion accepts a pair of N—H⋯O hydrogen bonds from an adjacent trimethoprim mol­ecule, which is similar to the carboxyl­ate–trimethoprim cation interaction present in the complex of di­hydro­folate reductase with trimethoprim. An O atom of the carboxyl group forms an intramolecular O—H⋯O hydrogen bond with the carboxyl­ate group, leading to a folded conformation for the hydrogen malonate ion. Each hydrogen malonate ion bridges two di­amino­pyrimidine cations, via N—H⋯O and C—H⋯N hydrogen bonds, leading to a supramolecular ribbon made up of alternating cations and anions. Two such inversion-related ribbons are cross-linked by (amino)N—H⋯O(methoxy) hydrogen bonds, (pyrimidine)C—H⋯O(methoxy) hydrogen bonds and π–π stacking involving the benzene planes. [ABSTRACT FROM AUTHOR]

In the title compound, C4H7N4O2+·SO42−·H2O, the asymmetric unit contains two amino­pyrimidinium cations, a sulfate anion and a water mol­ecule. These species are connected by N—H⋯O and O—H⋯O hydrogen bonds, resulting in a three-dimensional network. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C6H10N3+·Br−·C6H9N3·H2O, the asymmetric unit contains a 2-amino-4,6-di­methyl­pyrimidinium cation, a Br− anion, a neutral 2-amino-4,6-di­methyl­pyrimidine mol­ecule and a water mol­ecule. Each neutral base molecule is paired with another inversion-related molecule through N—H⋯N hydrogen bonds to form dimers, and these are linked to one another through water-mediated hydrogen bonds, generating a supramolecular ribbon. The cations also pair with one another through N—H⋯N hydrogen bonds. The cation pairs are stacked on top of the neutral pairs. The Br− anion also takes part in hydrogen bonding (N/O—H⋯Br). [ABSTRACT FROM AUTHOR]

In the title compound, C10H9N2+·C9H5INO4S-·2H2O, the 4,4'bipyridine molecule is protonated at one of the pyridine N atoms. These moieties self-assemble into a supramolecular chain along the a axis through N-H···N hydrogen bonds. The quinolinol OH group acts as a donor with respect to a sulfonate O atom [O-H···O(sulfonate)] and acts as an acceptor with respect to a C-H group of ferron [C-H···O(hydroxy)], forming a supramolecular chain along the b axis. These two types of supramolecular chains (one type made up of bipyridine motifs and the other made up of sulfoxine motifs) interact via π-π stacking, generating a three-dimensional framework. These chains are further crosslinked by C-H···O hydrogen bonds and O-H···O hydrogen bonds involving water molecules. [ABSTRACT FROM AUTHOR]

Investigates the conformation and hydrogen-bonding patterns of N[sup 6]-furfuryladenine hydrochloride. Adenine moiety existing as the N3-protonated N7-H tautomer; Orientation of the N6 substituent distal to the imidazole ring of the adenine base; Dihedral angle between the adenine plane and the furfuryl ring plane.

The titled dinuclear uranyl complex, U2O18N4H2·2(C5H7N2) 2(H2O) was crystallised in Monoclinic (C2/c) space group with the cell parameters a = 18.0728(3) b = 10.6896(3) c = 13.9068(3)Å, α = γ = 90.00° β = 103.988(2)°. In the structure, the U(VI) atom is eight coordinated with slightly distorted hexagonal bipyramidal geometry around the U(VI) ion. Two oxide ligands in the axial positions and four oxygen atoms from two bidentate nitrate ligands and two oxygen atoms from two hydroxy groups in the equatorial plane form the coordination sphere around the uranium atom. The two hydroxy groups act as bridging ligands between the uranyl ions generating a dinuclear unit having an inversion centre. The coordinated and non coordinated nitrate O atoms, axial uranyl O atoms, bridged hydroxy O atom, the non coordinated 2-aminopyridinium ion and the lattice water molecule play a vital role in assembling the three-dimensional structure via an extensive network of intermolecular O–H···O, N–H···O and C–H···O hydrogen bonds and aromatic π–π stacking interaction. The U(VI) atom is eight coordinated with slightly distorted hexagonal bipyramidal geometry. The three-dimensional structure is built through extensive network of intermolecular O–H···O, N–H···O, C–H···O hydrogen bonds and aromatic π–π stacking interaction. [ABSTRACT FROM AUTHOR]

In the title compound, C10H12O3N3S+·Cl−, 4-amino- N-(5-methyl-3-isoxazolyl)benzenesulfonamide is protonated on the amine N atom which is connected to the benzene ring. The geometry around the S atom is considerably distorted from ideal tetrahedral geometry. The crystal packing is stabilized by intermolecular N—H...N, N—H...Cl, N—H...O and C—H...O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title cocrystal, C9H9N5·C6H8O2, the asymmetric unit contains one 2,4-diamino-6-phenyl-1,3,5-triazine molecule and a sorbic acid molecule. The triazine molecules are base-paired [with a graph set of R22(8)] on either side via N—H...N hydrogen bonds, forming a supramolecular ribbon along the c axis. Each triazine molecule interacts with the carboxyl group of a sorbic acid molecule via N—H...O and O—H...N hydrogen bonds, generating R22(8) motifs. The supramolecular ribbons are interlinked by N—H...O hydrogen bonds involving the 2-amino group of the triazine molecules and the carboxyl O atom of the sorbic acid molecule. [ABSTRACT FROM AUTHOR]

In the title compound, C9H13N8O2+·C7H3N2O6−, the aminopyrimidine molecule is protonated at one of the pyrimidine N atoms. The carboxylate group of the 3,5-dinitrobenzoate anion interacts with the protonated N atom and the 2-amino group in a nearly linear fashion through a pair of N—H...O hydrogen bonds, generating the typical R22(8) motif. Two inversion-related pyrimidine units are connected through a pair of N—H...N hydrogen bonds, forming a cyclic hydrogen-bonded R22(8) motif. In addition to the base pairing, one of the carboxylate O atoms bridges the 4′-amino and 6′-amino groups on both side of the pairing, forming a DADA array. The molecular conformation of the cation is stabilized by two intramolecular N—H...O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title compound, C4H6N4O·C7H5NO4, there are two types of base-pairing motifs, one involving a pair of N—H...N hydrogen bonds and the other involving a pair of N—H...O hydrogen bonds. These paired molecules are further linked by N—H...O hydrogen bonds to generate DADA and DDAA ( D = donor and A = acceptor) arrays leading to a supramolecular sheet. [ABSTRACT FROM AUTHOR]

In the title compound, C12H14ClN4+·C6H4NO2−·H2O, the pyrimethamine molecule is protonated at one of the pyrimidine N atoms. The protonated N atom and 2-amino group of the cation interact with an adjacent nicotinate anion through a pair of N—H...O hydrogen bonds [graph set R22(8)]. The cation, anion and water molecule form a hydrogen-bonded ring motif with graph-set notation R42(8). The crystal structure is further stabilized by N—H...O and O—H...O hydrogen bonds and π–π interactions [centroid–centroid distance = 3.637 (6) Å]. [ABSTRACT FROM AUTHOR]

In the title cocrystal, C6H9N3O2·C8H6O4, both carboxylic acid groups of phthalic acid form an R22(8) ring motif (through N—H...O and O—H...N hydrogen bonds) on either side of the 2-amino-4,6-dimethoxypyrimidine molecule, generating a helical chain along the b axis. This chain is interpenetrated by a centrosymmetrically related chain to which it is linked by π–π stacking [perpendicular separation 3.332 Å, centroid–centroid distance 3.6424 (7) Å]. [ABSTRACT FROM AUTHOR]

In 2,4-diamino-5-( p-chlorophenyl)-6-ethylpyrimidinium hydrogen adipate, C12H14ClN4+·C6H9O4−, the protonated pyrimethamine cation interacts with the carboxylate group of the adipate ion through N—H...O hydrogen bonds, forming a cyclic hydrogen-bonded R22(8) motif. The carboxyl and carboxylate groups of the adipate ions are linked through O—H...O hydrogen bonds in a head-to-tail fashion, forming a chain. Anions and cations are further connected by an extensive network of N—H...O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound [systematic name: 2,4-diamino-5-(4-chlorophenyl)-6-ethylpyrimidin-1-ium 3,5-dinitrobenzoate], C12H14ClN4+·C7H3N2O6−, the pyrimethamine molecule is protonated at one of the pyrimidine N atoms. The carboxylate group of the 3,5-dinitrobenzoate anion forms double hydrogen bonds of type N—H...O, resulting in a fork-like interaction with the protonated diaminopyrimidine rings [graph-set notation R22(8)]. This motif self-assembles through a DDAA array of quadruple hydrogen bonds. The crystal structure is also stabilized by C—H...O hydrogen bonds. [ABSTRACT FROM AUTHOR]

The title compound [systematic name: 2,4-diamino-5-(4-chlorophenyl)-6-ethylpyrimdinium tetrafluoroborate], C12H14ClN4+·BF4−, is isomorphous with pyrimethamine perchlorate. The pyrimethamine (PMN) molecule is protonated at one of the pyrimidine N atoms. The protonated N atom and 2-amino group of the PMN cation interact with the tetrafluoroborate anion through a pair of N—H...F hydrogen bonds [graph set R22(8)]. The inversion-related PMN cations are linked through a pair of N—H...N hydrogen bonds. In addition to the base pairing, the F atoms bridge the 2-amino and 4-amino groups on either side of the paired bases, resulting in a complementary DADA array. [ABSTRACT FROM AUTHOR]

In the crystal structures of the title compounds, C6H10N3O2+·C7H5O3−·H2O, (I), C6H10N3O2+·C7H4NO4−·H2O, (II), and C6H10N3O2+·C4H5O6−·C6H9N3O2, (III), the 2-amino-4,6-di­meth­oxy­pyrimidinium cation [abbreviated as (MeO)2-Hampy+] inter­acts with the carboxyl­ate group of the corresponding anion through a pair of nearly parallel N—H⋯O hydrogen bonds to form R22(8) ring motifs. In (I), the (MeO)2-Hampy+ cation is centrosymmetrically paired through a pair of N—H⋯N hydrogen bonds involving the 2-amino group and a ring N atom forming an R22(8) motif. In (II), inversion-related R22(8) motifs (amino–pyrimidine–carboxyl­ate motifs) are further bridged by N—H⋯O hydrogen bonds on either side forming a DDAA array of quadruple hydrogen bonds. This array is extended further on either side by Owater—H⋯Ometh­oxy hydrogen bonds, resulting in an array of six hydrogen bonds ( ADDAAD). The water mol­ecule plays a pivotal role, and five hydrogen-bonded fused rings are formed around the water mol­ecule. In (III), the carb­oxy group of the tartrate anion inter­acts with the ring N atom and 2-amino group of the neutral (MeO)2-ampy mol­ecule through N—H⋯O and O—H⋯N hydrogen bonds. There is also an intra­molecular O—H⋯O hydrogen bond in the tartrate anion. In all three crystal structures, C—H⋯O hydrogen bonds are observed. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C6H10N3+·C7H5O3-, the asymmetric unit contains four crystallographically independent 2-amino-4,6-dimethylpyrimidinium and salicylate ions (Z = 8). In each of these, one of the pyrimidine N atoms is protonated, and the carboxylate group of the salicylate ion interacts with the pyrimidine group through a pair of N—H…O hydrogen bonds, forming an R2²(8) motif. The pyrimidine cations also form base pairs via a pair of N—H…N hydrogen bonds (involving the amino group and the unprotonated ring N atom), forming another R2²(8) motif. Three such R2²(8) motifs, fused together, constitute a closed cyclic aggregate, and the linking of these aggregates, arranged in consecutive layers, can be analysed in terms of off-face stacking interactions. [ABSTRACT FROM AUTHOR]

In the title compounds, namely 2,4-diamino-5-[(3,4,5-trimethoxy­phenyl)methyl]­pyrimidin-1-ium pyridine-2-carboxyl­ate, C14H19N4O3+·C6H4NO2−, (I), and 2-amino-4,6-dimethyl­pyrimidin-1-ium pyridine-2-carboxyl­ate hemihydrate, C6H10N3+·C6H4NO2−·0.5H2O, (II), the trimethoprim and 2-amino-4,6-dimethyl­pyrimidin-1-ium cations are protonated at one of the pyrimidine N atoms. In (I), bifurcated hydrogen bonds are observed between a picolinate O atom, the protonated N atom and the 2-amino group; the graph-set designator is R21(6). The pyrimidine moieties of the trimethoprim cations are centrosymmetrically paired through a pair of N—H⋯N hydrogen bonds. In addition to the base pairing, one of the picolinate O atoms bridges the 2- and 4-amino groups on either side of the paired bases, resulting in a complementary DADA array. In (II), the carboxyl­ate group of the picolinate anion binds with the protonated pyrimidine N atom and the 2-amino group of the pyrimidine moiety through a pair of N—H⋯O hydrogen bonds, leading to the common ring motif R22(8). The water mol­ecule, which resides on a twofold rotation axis, bridges the carboxyl­ate group of the picolinate anion via O—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title compound [systematic name: 2,4-diamino-5-(3,4,5-trimethoxy­benz­yl)pyrimidinium tetrafluoroborate], C14H19N4O3+·BF4−, the trimethoprim (TMP) mol­ecule is protonated at one of the pyrimidine N atoms. The protonated N atom and 2-amine group of the TMP cation inter­act with the tetrafluoroborate anion through a pair of N—H⋯F hydrogen bonds [graph set R22(8)]. The inversion-related TMP cations are linked through a pair of N—H⋯N hydrogen bonds. The 2-amine group of one TMP cation and the 4-amine group of another cation are bridged by a meth­oxy O atom, via N—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title compound, C6H9N3·2C9H8O2, an amino­pyrimidine–cinnamic acid 1:2 cocrystal, the 2-amino-4,6-dimethyl­pyrimidine mol­ecule forms two eight-membered hydrogen-bonded rings [ R22(8) motif] with the carboxylic acid groups from two independent cinnamic acid mol­ecules via N—H⋯O and O—H⋯N hydrogen bonds. The cinnamic acid mol­ecules are linked by C—H⋯O hydrogen bonds to form chains along two axes. [ABSTRACT FROM AUTHOR]

The title compound, 2,4-diamino-5-(4-chloro­phen­yl)-6-ethyl­pyrimidine-1,3-diium dinitrate, C12H15ClN42+·2NO3−, contains two crystallographically independent pyrimethamine (PMN) mol­ecules, which differ in the relative orientations of the pyrimidine and benzene rings and of the eth­yl substitutents. In both pyrimethamine mol­ecules, all the pyrimidine N atoms are protonated, unlike most related compounds, in which only one pyrimidine N atom is protonated. The two pyrimethamine moieties are bridged by a variety of N—H⋯O(nitrate) inter­actions, including some three-centre hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title molecular salt, C12H10N5O+·NO3-, the adenine unit has an N9-protonated N(7)--H tautomeric form with non-protonated N¹ and N³ atoms. The dihedral angle between the adenine ring system and the phenyl ring is 51.10(10)°. The typical intra­molecular N7--H···O hydrogen bond with an S(7) graph-set motif is also present. The benzoyl­adeninium cations also form base pairs through N--H···O and C--H···N hydrogen bonds involving the Watson-Crick face of the adenine ring and the C and O atoms of the benzoyl ring of an adjacent cation, forming a supra­molecular ribbon with R2²(9) rings. Benzoyl­adeninum cations are also bridged by one of the oxygen atoms of the nitrate anion, which acts as a double acceptor, forming a pair of N--HH···O hydrogen bonds to generate a second ribbon motif. These ribbons together with p-p stacking inter­actions between the phenyl ring and the five- and six-membered adenine rings of adjacent mol­ecules generate a three-dimensional supra­molecular architecture. [ABSTRACT FROM AUTHOR]

Three salts, namely 2-amino-4,6-dimethylpyrimidin-1-ium thiobarbiturate trihydrate (I), 2-amino-4,6-dimethoxypyrimidin-1-ium thiobarbiturate dihydrate (II) and 2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl)pyrimidin-1-ium thiobarbiturate (III), were synthesized and characterized by IR and X-ray diffraction techniques. The primary interaction between the acid and base happens via N-H...O hydrogen bonds in (II) and (III), and via water-mediated N-H...O W and O W-H W...S in (I). The water molecules present in compound (I) form a (H2O)12 water cluster via water-water interactions. In all three compounds (I)-(III), thiobarbiturate anions form self-complementary pairs with a robust R22(8) motif via a pair of N-H...O/N-H...S hydrogen bonds. They mimic the nucleobase base pairs by utilizing the same groups (thymine/uracil uses N3-H and C4=O8 groups during the formation of Watson-Crick and Hoogsteen base pairs with adenine). Compound (I) forms a water-mediated base pair through N-H...O W hydrogen bonds and forms an R42(12) motif. The formation of N-H...S hydrogen bonds, water-mediated base pairs and water-water interactions in these crystal systems offers scope for these systems to be considered as a model in the study of hydration of nucleobases and water-mediated nucleobase base pairs in macromolecules. [ABSTRACT FROM AUTHOR]

Abstract: Interesting hydrogen-bonded supramolecular patterns have been achieved by hexafluorosilicate anion in the crystal structures of bis(thiabendazole) hexafluorosilicate dihydrate 1 and bis(pyrimethamine) hexafluorosilicate 2. In compound 1, the nitrogen atom of the benzimidazole ring rather than that of the thiazole ring is protonated. Water molecule is hydrogen-bonded with SiF6 2− anion through O–H⋯F hydrogen bonds to form a twelve membered cyclic hydrogen-bonded cluster. This cluster is self-organized to form a supramolecular chain. In the crystal structure of compound 2, the asymmetric unit contains two crystallographically independent protonated pyrimethamine (PMN) cations and a hexafluorosilicate SiF6 2− anion. The combination N–H⋯F and N–H⋯N hydrogen bonds results in the formation of complementary DADA (D and A represent donor and acceptor, respectively) array motif. It confirms that DADA array motif is a robust synthon in the crystal structures of diaminopyrimidine salts. [Copyright &y& Elsevier]