Hydrogen‐bonded supramolecular motifs in 2‐amino‐4,6‐dimethoxypyrimidinium picrate and pyrimethaminium picrate dimethyl sulfoxide solvate

In the crystal structures of 2‐amino‐4,6‐dimethoxypyrimidinium 2,4,6‐trinitrophenolate (picrate), C₆H₁₀N₃O₂⁺·C₆H₂N₃O₇⁻, (I), and 2,4‐diamino‐5‐(4‐chlorophenyl)‐6‐ethylpyrimidin‐1‐ium (pyrimethaminium or PMN) picrate dimethyl sulfoxide solvate, C₁₂H₁₄ClN₄⁺·C₆H₂N₃O₇⁻·C₂H₆OS, (II), the 2‐amino‐4,6‐dimethoxypyrimidine and PMN cations are protonated at one of the pyrimidine N atoms. The picrate anion interacts with the protonated cations through bifurcated N—H...O hydrogen bonds, forming R₂¹(6) and R₁²(6) ring motifs. In (I), Z′ = 2. In (II), two inversion‐related PMN cations are connected through a pair of N—H...N hydrogen bonds involving the 4‐amino group and the uncharged N atom of the pyrimidine ring, forming a cyclic hydrogen‐bonded R₂²(8) motif. In addition to the pairing, the O atom of the dimethyl sulfoxide solvent molecule bridges the 2‐amino and 4‐amino groups on both sides of the paired bases, resulting in a self‐complementary …DADA… array of quadruple hydrogen‐bonding patterns.     

Charge‐assisted hydrogen‐bonded supramolecular networks in acetoguanaminium hydrogen phthalate,acetoguanaminium hydrogen maleate and acetoguanaminium 3‐hydroxypicolinate monohydrate

In 2,4‐diamino‐6‐methyl‐1,3,5‐triazin‐1‐ium (acetoguanaminium) hydrogen phthalate, C₄H₈N₅⁺·C₈H₅O₄⁻, (I), acetoguanaminium hydrogen maleate, C₄H₈N₅⁺·C₄H₃O₄⁻, (II), and acetoguanaminium 3‐hydroxypicolinate monohydrate, C₄H₈N₅⁺·C₆H₄NO₃⁻·H₂O, (III), the acetoguanaminium cations interact with the carboxylate groups of the corresponding anions via a pair of nearly parallel N—H...O hydrogen bonds, forming R₂²(8) ring motifs. In (II) and (III), N—H...N base‐pairing is observed, while there is none in (I). In (II), a series of fused R₃²(8), R₂²(8) and R₃²(8) hydrogen‐bonded rings plus fused R₂²(8), R₆²(12) and R₂²(8) ring motifs occur alternately, aggregating into a supramolecular ladder‐like arrangement. In (III), R₂²(8) motifs occur on either side of a further ring formed by pairs of N—H...O hydrogen bonds, forming an array of three fused hydrogen‐bonded rings. In (I) and (II), the anions form a typical intramolecular O—H...O hydrogen bond with graph set S(7), whereas in (III) an intramolecular hydrogen bond with graph set S(6) is formed.     

Hydrogen‐bonding patterns in pyrimethaminium dinitrate

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.     

Hydrogen‐bonding motifs in 3‐carboxyanilinium bromide and iodide

In the title compounds, C₇H₈NO₂⁺·Br⁻, (I), and C₇H₈NO₂⁺·I⁻, (II), the asymmetric unit contains a discrete 3‐carboxyanilinium cation, with a protonated amine group, and a halide anion. The compounds are not isostructural, and the crystal structures of (I) and (II) are characterized by different two‐dimensional hydrogen‐bonded networks. The ions in (I) are connected into ladder‐like ribbons via N—H...Br hydrogen bonds, while classic cyclic O—H...O hydrogen bonds between adjacent carboxylic acid functions link adjacent ribbons to give three characteristic graph‐set motifs, viz. C₂¹(4), R₄²(8) and R₂²(8). The ions in (II) are connected via N—H...I, N—H...O and O—H...I hydrogen bonds, also with three characteristic graph‐set motifs, viz. C(7), C₂¹(4) and R₄²(18), but an O—H...O interaction is not present.     

Hydrogen‐bonded structures of the isomeric 2‐, 3‐ and 4‐carbamoylpyridinium hydrogen chloranilates

In the three isomeric salts, all C₆H₇N₂O⁺·C₆HCl₂O₄⁻, of chloranilic acid (2,5‐dichloro‐3,6‐dihydroxy‐1,4‐benzoquinone) with 2‐, 3‐ and 4‐carbamoylpyridine, namely, 2‐carbamoylpyridinium hydrogen chloranilate (systematic name: 2‐carbamoylpyridinium 2,5‐dichloro‐4‐hydroxy‐3,6‐dioxocyclohexa‐1,4‐dienolate), (I), 3‐carbamoylpyridinium hydrogen chloranilate, (II), and 4‐carbamoylpyridinium hydrogen chloranilate, (III), acid–base interactions involving H‐atom transfer are observed. The shortest interactions between the cation and the anion in (I) and (II) are pyridinium N—H...(O,O) bifurcated hydrogen bonds, which act as the primary intermolecular interaction in each crystal structure. In (III), an amide N—H...(O,O) bifurcated hydrogen bond, which is much weaker than the bifurcated hydrogen bonds in (I) and (II), connects the cation and the anion.     

Hydrogen‐bonded supramolecular polymers from derivatives of α‐amino‐ε‐caprolactam: A bio‐based material

Hydrogen‐bonded supramolecular polymers were prepared from the derivatives of α‐amino‐ε‐caprolactam (ACL), obtained from a renewable resource. Several self‐complimentary bis‐ or tetra‐caprolactam monomers were synthesized by varying the number of carbons of the spacer between the hydrogen‐bonding end groups. Physical properties of these hydrogen‐bonded polymers were clearly demonstrated by differential scanning colorimetry, solid‐state NMR, and X‐ray powder diffraction analyses. The supramolecular behavior was also supported by fiber formation from the melt for several of these compounds, and stable glassy materials were prepared from the physical mixtures of two different biscaprolactams. The self‐association ability of ACL was also used by incorporating ACL at the chain ends of low‐molecular weight Jeffamine (M_n = 900 g/mol) using urea and amide linkages. The transformation of this liquid oligomer at room temperature into a self‐standing, transparent film clearly showed the improvement in mechanical properties obtained by the introduction of terminal hydrogen‐bonding groups. Finally, the use of monomers with a functionality of four gave rise to network formation either alone or combination with bifunctional monomers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Hydrogen‐bonded 1,2‐bis(4‐pyridyl)ethylene and maleic acid

The title compound (systematic name: 4,4′‐ethyl­ene­dipyridinium dimaleate), C₁₂H₁₂N₂²⁺·2C₄H₃O₄^?, is a 1:2 adduct of 1,2‐bis(4‐pyridyl)­ethyl­ene (BPE) and maleic acid (MA). The interaction between the two components in the molecular complex is due to intermolecular hydrogen bonding via an N⁺—H?O^? hydrogen bond.     

Hydrogen‐bonded two‐ and three‐dimensional polymeric structures in the ammonium salts of 3,5‐dinitrobenzoic acid, 4‐nitrobenzoic acid and 2,4‐dichlorobenzoic acid

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.     

Hydrogen‐bonded supramolecular polymers containing dimethylsilane groups: Synthesis,crystal structure,and characterization

Bis[N‐(4‐carboxyphenyl)phtalimidyl]dimethylsilane prepared by the reaction between bis(3,4‐dicarboxyphenyl)dimethylsilane anhydride and p‐aminobenzoic acid has been used to built three novel hydrogen‐bonded supramolecular polymers as a result of cocrystallization with pyridine derivatives: 4,4′‐bipyridyl ( SP1 ), 1,2‐bis(4‐pyridyl)ethylene ( SP2 ), and 4,4′‐azopyridine ( SP3 ). The structures of the dianhydride, diacid, and derived supramolecular polymers were investigated by Fourier transform infrared (FTIR) and proton magnetic resonance (¹H NMR) spectroscopy. Self‐assembling was proved by the presence of the IR absorption bands around 1900 and 2400 cm^?1 specific for hydrogen bond. The association constant values were estimated by using FTIR spectroscopy in solid state. According to X‐ray diffraction study, the bis(3,4‐dicarboxyphenyl)dimethylsilane anhydride ( 1 ) has an isolated molecular structure. Bis[N‐(4‐carboxyphenyl)phtalimidyl]dimethylsilane ( 2 ) molecules are associated in the crystal structure via dimeric O? H … O hydrogen bonds resulting in the wavy 1D supramolecular chain. The main packing motif for SP1 and SP3 is represented by wavy chain formed by alternating sequences of 4,4′‐bipyridyl or 4,4′‐azopyridine and bis[N(4‐carboxyphenyl)phtalimidyl]dimethylsilane molecules linked by O? H … N hydrogen bonds. Thermal behavior was studied by differential scanning calorimetry and thermogravimetric analysis. The ability for the structuration in film was emphasized by atomic force microscopy. The molecular transport ability of the reversible associations was estimated by dynamic water vapor sorption (DVS) analysis. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Hydrogen‐bonded molecular ladders in S‐(4‐nitrophenyl)thioglycolic acid

Molecules of the title compound, [(4‐nitro­phenyl)­sulfanyl]­acetic acid, C₈H₇NO₄S, are linked by paired O—H?O hydrogen bonds [H?O 1.81 Å, O?O 2.6456 (15) Å and O—H?O 178°] into centrosymmetric dimers containing an R(8) motif. A single C—H?O hydrogen bond having a nitro O atom as acceptor [H?O 2.47 Å, 3.3018 (19) Å and C—H?O 147°] links the dimers into a molecular ladder, and neighbouring ladders are weakly linked into sheets by aromatic π–π‐stacking interactions.     

Hydrogen‐bonded molecular ladders in 1,4‐bis(4‐chlorophenylsulfonyl)‐2,5‐dimethylbenzene

In the title compound, C₂₀H₁₆Cl₂O₄S₂, the mol­ecules lie across centres of inversion. A single type of intermolecular C—H?O hydrogen bond, with a C?O distance of 3.254 (3) Å and a C—H?O angle of 132°, links the mol­ecules into ladders whose uprights form C(6) chains and whose rungs enclose centrosymmetric R(22) rings.     

Hydrogen‐bonded supramolecular networks of N,N′‐bis(4‐pyridylmethyl)oxalamide and 4,4′‐{[oxalylbis(azanediyl)]dimethylene}dipyridinium dinitrate

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.     

Hydrogen‐bonded networks in 1‐(4‐methoxyphenyl)‐2,2‐dimethylpropan‐1‐ol

The asymmetric unit of the title compound, C₁₂H₁₈O₂, contains two independent molecules. They differ only slightly in conformation but form completely different intermolecular hydrogen‐bonded arrays. One molecule exhibits disorder in the hydroxy group region, but this does not influence the formation of hydrogen bonds. The bulky tert‐butyl group on one side of the carbinol C atom and the benzene ring on the other side promote the formation of discrete dimeric motifs via hydrogen‐bridged hydroxy groups. Dimers are further joined by strong hydroxy–methoxy O—H...O bonds to form chains with dangling alcohol groups. Weaker intermolecular C—H...O interactions mediate the formation of a two‐dimensional network.     

Hydrogen‐bonded network in biphenyl‐4,4′‐diphosphonic acid

The crystal structure of the title compound, C₁₂H₁₂O₆P₂, displays two different regions alternating along the a axis: a hydrogen‐bonded region encompassing the end‐positioned phosphonic acid groups and a hydrophobic region formed by the aromatic spacers. The asymmetric unit contains only half of the biphenyl‐4,4′‐diphosphonic acid (4,4′‐bpdp) molecule, which is symmetric with an inversion centre imposed at the mid‐point between the two aromatic rings. The periodic organization of the molecules is controlled by two strong O—H...O interactions between the phosphonic acid sites. Weak C—H...π interactions are established in the aromatic regions.     

Hydrogen‐bonded assemblies of 5,10,15,20‐tetrakis(4‐hydroxyphenyl)porphyrin with dimethylformamide,dimethylacetamide and water

The title free base porphyrin compound forms hydrogen‐bonded adducts with N,N‐dimethylformamide, C₄₄H₃₀N₄O₄·4C₃H₇NO, (I), a mixture of N,N‐dimethylformamide and water, C₄₄H₃₀N₄O₄·4C₃H₇NO·H₂O, (II), and a mixture of N,N‐dimethylacetamide and water, C₄₄H₃₀N₄O₄·6C₃H₇NO·2H₂O, (III). Total solvation of the four hydroxy functions of the porphyrin molecules characterizes all three compounds, thus preventing its supramolecular association into extended network architectures. In (I), the asymmetric unit consist of two five‐component adduct species, while in (III), the nine‐component entities reside on centres of inversion. This report provides the first structural characterizations of the free base tetra(hydroxyphenyl)porphyrin. It also demonstrates that the presence of strong Lewis bases, such as dimethylformamide or dimethylacetamide, in the crystallization mixture prevents direct supramolecular networking of the porphyrin ligands via O—H...O—H hydrogen bonds, due to their competing O—H...N(base) interaction with the hydroxy functions. The crystal packing of compounds (I)–(III) resembles that of other hydrogen‐bonding‐assisted tetraarylporphyrin clathrates.     

Hydrogen‐bonded structures of the isomeric compounds of phthalazine with 3‐chloro‐2‐nitrobenzoic acid, 4‐chloro‐2‐nitrobenzoic acid and 4‐chloro‐3‐nitrobenzoic acid

The structures of three isomeric compounds, C₇H₄ClNO₄·C₈H₆N₂, of phthalazine with chloro‐ and nitro‐substituted benzoic acid, namely, 3‐chloro‐2‐nitrobenzoic acid–phthalazine (1/1), (I), 4‐chloro‐2‐nitrobenzoic acid–phthalazine (1/1), (II), and 4‐chloro‐3‐nitrobenzoic acid–phthalazine (1/1), (III), have been determined at 190 K. In the asymmetric unit of each compound, there are two crystallographically independent chloronitrobenzoic acid–phthalazine units, in each of which the two components are held together by a short hydrogen bond between an N atom of the base and a carboxyl O atom. In one hydrogen‐bonded unit of (I) and in two units of (II), a weak C—H...O interaction is also observed between the two components. The N...O distances are 2.5715 (15) and 2.5397 (17) Å for (I), 2.5655 (13) and 2.6081 (13) Å for (II), and 2.613 (2) and 2.589 (2) Å for (III). In both hydrogen‐bonded units of (I) and (II), the H atoms are each disordered over two positions with (N site):(O site) occupancies of 0.35 (3):0.65 (3) and 0.31 (3):0.69 (3) for (I), and 0.32 (3):0.68 (3) and 0.30 (3):0.70 (3) for (II). The H atoms in the hydrogen‐bonded units of (III) are located at the O‐atom sites.     

Inter‐ring and endo anomeric effects,and hydrogen‐bonded supramolecular motifs in two 2,4,6,8‐tetraazabicyclo[3.3.0]octane derivatives

In 2,4,6,8‐tetrakis(4‐chlorophenyl)‐2,4,6,8‐tetraazabicyclo[3.3.0]octane, C₂₈H₂₂Cl₄N₄, the imidazolidine rings adopt envelope conformations, which are favoured by two equal endo anomeric effects. The molecule lies on a crystallographic twofold axis and molecules are linked into a three‐dimensional framework via two C—H...Cl hydrogen bonds. In 2,4,6,8‐tetrakis(4‐methoxyphenyl)‐2,4,6,8‐tetraazabicyclo[3.3.0]octane, C₃₂H₃₄N₄O₄, one of the methyl groups is disordered over two sets of sites and the same methyl group participates in an intermolecular C—H...O hydrogen bond, which in turn causes a considerable deviation from the preferred conformation. There are two unequal inter‐ring anomeric effects in the N—C—N groups. Molecules are linked into corrugated sheets by one C—H...π hydrogen bond and two independent C—H...O hydrogen bonds involving methoxy groups.     

Hydro­gen‐bonded supramolecular motifs in 4,4′‐bipyridinium 8‐hydroxy‐7‐iodo­quinoline‐5‐sulfonate dihydrate

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 viaπ–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.     

A Homochiral Metal‐Dipeptide Supramolecular Framework Including a Hydrogen‐bonded Guest Network of Water and Uncoordinated 4, 4′‐Bipyridine

Abstract. The self‐assembly of glycyl‐L ‐leucine, Cu(NO₃)₂ · 3H₂O and 4, 4′‐bipyridine resulted in the tetranuclear‐based metal‐dipeptide supramolecular framework [Cu₄(C₈H₁₄N₂O₃)₄(H₂O)₂(C₁₀H₈N₂)₂] · (C₁₀H₈N₂) · 13H₂O ( 1 ). In the structure, the 4, 4′‐bipyridine‐bridged tetranuclear complex of Cu^II‐glycyl‐L ‐leucine interacts with each other to form a 1D hydrogen‐bonded chain including uncoordinated 4, 4′‐bipyridine and an interesting water chain in different channels. Under similar reaction conditions, racemic glycyl‐D ,L ‐leucine gave rise to the centrosymmetric dinuclear complex [Cu₂(C₈H₁₄N₂O₃)₂(C₁₀H₈N₂)] · 2H₂O ( 2 ), which is linked into a 2D hydrogen‐bonded structure without 4, 4′‐bipyridine included.     

Hydrogen‐bonded sheet structures in neutral,anionic and hydrated 6‐amino‐2‐(morpholin‐4‐yl)‐5‐nitrosopyrimidines

In each of 6‐amino‐3‐methyl‐2‐(morpholin‐4‐yl)‐5‐nitrosopyrimidin‐4(3H)‐one, C₉H₁₃N₅O₃, (I), morpholin‐4‐ium 4‐amino‐2‐(morpholin‐4‐yl)‐5‐nitroso‐6‐oxo‐1,6‐dihydropyrimidin‐1‐ide, C₄H₁₀NO⁺·C₈H₁₀N₅O₃⁻, (II), and 6‐amino‐2‐(morpholin‐4‐yl)‐5‐nitrosopyrimidin‐4(3H)‐one hemihydrate, C₈H₁₁N₅O₃·0.5H₂O, (III), the bond distances within the pyrimidine components are consistent with significant electronic polarization, which is most marked in (II) and least marked in (I). Despite the high level of substitution, the pyrimidine rings are all effectively planar, and in each of the pyrimidine components, there are intramolecular N—H...O hydrogen bonds. In each compound, the organic components are linked by multiple N—H...O hydrogen bonds to form sheets of widely differing construction, and in compound (III) adjacent sheets are linked by the water molecules, so forming a three‐dimensional hydrogen‐bonded framework. This study also contains the first direct geometric comparison between the electronic polarization in a neutral aminonitrosopyrimidine and that in its ring‐deprotonated conjugate anion in a metal‐free environment.