Infinite Hydrogen-bonded Chains Research Articles

Chain-Length-Dependent Hydrogen-Bonded Self-Assembly of Terminally Functionalized Discrete Polyketones

Here, we report the synthesis and the chain-length-dependent self-assembling behaviors of discrete di-, tetra-, and hexaketones terminally functionalized with hydrogen-bonding carboxyl (C1, C2, and C3) and 3-acylaminopyridine groups (P1, P2, and P3). These polyketones were prepared by the coupling reactions of silylated analogues of 3,3-dimethylpentane-2,4-dione and t-butyl 2,2-dimethyl-3-oxobutanoate and the subsequent hydrolysis or amidation with 3-aminopyridine. Single-crystal X-ray diffraction analysis revealed that C1 and C2 form helical assemblies in which the components are connected by the dimerization of terminal carboxyl groups, whereas the longer C3 showed infinite hydrogen-bonded chains mediated by 1,4-dioxane used as a crystallization solvent. Pyridine-terminated P1 exhibited a three-dimensional hydrogen-bonded network owing to multiple NH···N(pyridine) hydrogen bonds in the solid state. P2 generated a double-helix-like fiber structure in the crystalline state. Among the pyridine-terminated polyketones P1–P3, only P2 showed gelation behavior in chloroform (100 mM concentration) at 25 °C. The scanning electron microscopy measurement of xerogel P2 revealed the formation of rod-like structures with a thickness of approximately 0.5–3.5 μm. These results demonstrate that the precise control of the polyketone chain length can significantly alter hydrogen-bonded self-assembly in the solid state and in solution even with the same terminal structures.

Crystal structure of 4-bromo-N-(propyl-carbamo-yl)benzene-sulfonamide.

The title compound, C10H13BrN2O3S, 1, contains a sulfonyl urea moiety, which possesses potential therapeutic functions (e.g., anti-diabetic and herbicidal). The geometry of 1 is similar to its closely related analogues, chlorpropamide and tolbutamide. This compound crystallizes in the monoclinic space group C2/c, having one mol-ecule in its asymmetric unit. The crystal structure of 1, recorded at 296 K, shows inter-molecular N-H⋯O and C-H⋯O-type infinite hydrogen-bonded chains involving the sulfonyl urea moiety. Hirshfeld surface analysis and the two-dimensional fingerprint plots confirmed hydrogen bonding as the dominant feature in the crystal packing.

Crystalline Forms of Trazodone Dihydrates.

In this study, treatment of anhydrous trazodone powder with ammonium carbamate in warm water crystallised two new polymorphs or dihydrates of trazodone after 5 h, whose structures were determined by X-ray single crystal diffraction. Each dihydrate contains infinite zigzag hydrogen-bonded chains of water molecules, which are stabilised by the N4 acceptor atom of the piperazine ring and the pendant carbonyl O1 atom of the triazole ring, as well as other water molecules. The strong dipole moment expected for the O1 atom makes it a good hydrogen bond acceptor for stabilising the chains of water molecules. Each molecule of trazodone has a similar conformation in both hydrates, except for the propyl chains, which adopt different conformations: anti-gauche in the β hydrate (triazole N-C-C-C and C-C-C-piperazine N) and anti-anti in the γ hydrate. Both piperazine rings adopt chair conformations, and the exocyclic N-C bonds are in equatorial orientations. The Hirshfeld surfaces and two-dimensional fingerprint plots for the polymorphs were calculated using CrystalExplorer17, which indicated contacts significantly shorter than the sum of the van der Waals radii in the vicinity of the piperazine N4 and triazole O1 atoms corresponding to the strong hydrogen bonds accepted by these atoms.

Dl-Piperidinium-2-carboxyl-ate bis-(hydrogen peroxide): unusual hydrogen-bonded peroxide chains.

The title compound, C6H11NO2·2H2O2, is the richest (by molar ratio) in hydrogen peroxide among the peroxosolvates of aliphatic α-amino acids. The asymmetric unit contains a zwitterionic pipecolinic acid mol-ecule and two hydrogen peroxide mol-ecules. The two crystallographically independent hydrogen peroxide mol-ecules form a different number of hydrogen bonds: one forms two as donor and two as acceptor ([2,2] mode) and the other forms two as donor and one as acceptor ([2,1] mode). The latter hydrogen peroxide mol-ecule forms infinite hydrogen-bonded hydro-peroxo chains running along the c-axis direction, which is unusual for aliphatic α-amino acid peroxosolvates.

A novel crystal form of metacetamol: the first example of a hydrated form.

We report the crystal structure and crystallization conditions of a first hydrated form of metacetamol (a hemihydrate), C8H9NO2·0.5H2O. It crystallizes from metacetamol-saturated 1:1 (v/v) water-ethanol solutions in a monoclinic structure (space group P21/n) and contains eight metacetamol and four water molecules per unit cell. The conformations of the molecules are the same as in polymorph II of metacetamol, which ensures the formation of hydrogen-bonded dimers and R22(16) ring motifs in its crystal structure similar to those in polymorph II. Unlike in form II, however, these dimers in the hemihydrate are connected through water molecules into infinite hydrogen-bonded molecular chains. Different chains are linked to each other by metacetamol-water and metacetamol-metacetamol hydrogen bonds, the latter type being also present in polymorph I. The overall noncovalent network of the hemihydrate is well developed and several types of hydrogen bonds are responsible for its formation.

Succinic, fumaric, adipic and oxalic acid cocrystals of promethazine hydrochloride

Novel cocrystals of promethazine hydrochloride [PTZ-Cl; systematic name: N,N-dimethyl-1-(10H-phenothiazin-10-yl)propan-2-aminium chloride] with succinic acid (PTZ-Cl-succinic, C17H21N2S+·Cl-·0.5C4H6O4), fumaric acid (PTZ-Cl-fumaric, C17H21N2S+·Cl-·0.5C4H4O4) and adipic acid (PTZ-Cl-adipic, C17H21N2S+·Cl-·0.5C6H10O4) were prepared by solvent drop grinding and slow evaporation from acetonitrile solution, along with two oxalic acid cocrystals which were prepared in tetrahydrofuran (the oxalic acid hemisolvate, PTZ-Cl-oxalic, C17H21N2S+·Cl-·0.5C2H2O4) and nitromethane (the hydrogen oxalate salt, PTZ-oxalic, C17H21N2S+·C2HO4-). The crystal structures obtained by crystallization from tetrahydrofuran and acetonitrile include the Cl- ion in the lattice structures, while the Cl- ion is missing from the crystal structure obtained by crystallization from nitromethane (PTZ-oxalic). In order to explain the formation of the two types of supramolecular configurations with oxalic acid, the intermolecular interaction energies were calculated in the presence of the two solvents and the equilibrium configurations were determined using density functional theory (DFT). The cocrystals were studied by X-ray diffraction, IR spectroscopy and differential scanning calorimetry. Additionally, a stability test under special conditions and water solubility were also investigated. PTZ-Cl-succinic, PTZ-Cl-fumaric and PTZ-Cl-adipic crystallized having similar lattice parameter values, and showed a 2:1 PTZ-Cl to dicarboxylic acid stoichiometry. PTZ-Cl-oxalic crystallized in a 2:1 stoichiometric ratio, while the structure lacking the Cl atom belongs has a 1:1 stoichiometry. All the obtained crystals exhibit hydrogen bonds of the type PTZ...Cl...(dicarboxylic acid)...Cl...PTZ, except for PTZ-oxalic, which forms bifurcated bonds between the hydrogen oxalate and promethazinium ions, along with an infinite hydrogen-bonded chain between the hydrogen oxalate anions.

Effects of Weak Hydrogen-Bonding Interactions on Supramolecular Assemblies of N,N-Dimethyl-1-admantylamine

The reaction of N,N-dimethyl-1-admantylamine (ada) and inorganic acids or trivalent metal chlorides in the hydrochloric acid medium yields four new supramolecular salts, i.e. (adaH+)3·(SbCl3)·(SbCl4−)·(SbCl52−) (1), (adaH+)·(FeCl4−) (2), (adaH+)·(ClO4−) (3), and (adaH+)·(I3−) (4), respectively. Compound 5, (dtaH+)2·(I3−)·I− (dta = N,N-dimethyl-2,4,6-trimethylaniline) was also prepared for comparison with 4. Structural analyses reveals that the weak hydrogen-bonding interactions play a crucial role in the formation of various hydrogen-bonding networks. 3D supramolecular architectures are observed in 3, independent 1D infinite hydrogen-bonded chain structures are observed in 1, and discrete structures are observed in 2, 4 and 5. Surprisingly, due to the coexistence of SbCl3, [SbCl4]− and [SbCl5]2−, compound 1 proves to be a unique example according to the Cambridge Structure Database (CSD). Structural analysis reveals that the weak hydrogen-bonding interactions play a crucial role in the formation of various hydrogen-bonding networks. 3D supramolecular architectures are observed in 3, independent 1D infinite hydrogen-bonding chain structures are observed in 1 and discrete structures are observed in 2, 4 and 5.

A fluorophore-labelled copper complex: crystal structure, hybrid cyclic water-perchlorate cluster and biological properties.

A fluorophore-labelled copper(II) complex, aquabis(dimethylformamide-κO)(perchlorato-κO)[2-(quinolin-2-yl)-1,3-oxazolo[4,5-f][1,10]phenanthroline]copper(II) perchlorate monohydrate, [Cu(ClO4)(C22H12N4O)(C3H7NO)2(H2O)]ClO4·H2O, has been synthesized and characterized. A cyclic hydrogen-bonded water-perchlorate anionic cluster, i.e. [(ClO4)2(H2O)2]2-, has been identified within the structure. Each cyclic anionic cluster unit is interconnected by hydrogen bonding to the cation. The cations join into an infinite hydrogen-bonded chain running in the [010] direction. Furthermore, interaction of the complex with calf-thymus DNA (CT-DNA) and cellular localization within the cells was explored. Spectroscopic studies indicate that the compound has a good affinity for DNA and stains the nucleus of the cells.

1D hydrogen-bonded infinite chains from tetraaza macrocycle nickel(II) complexes and ligands

The reaction of square planar complex [Ni(L2)]Cl2·2H2O (L2=3,14-diethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane) with ligands KNCS and H2cpdc generates 1D hydrogen-bonded infinite chains [Ni(L2)(NCS)2] (1) and [Ni(L2)(H-cpdc)2] (2) (H2cpdc=cyclopropanedicarboxylic acid). These compounds have been characterized by X-ray crystallography, spectroscopic, cyclic voltammetry and thermogravimetry. The crystal structures of compounds 1 and 2 show that each nickel(II) centre has an elongated distorted octahedral geometry with the axial ligands. Electronic spectra and redox potentials of the complexes 1 and 2 exhibit a high-spin octahedral environment, which is reflected by the nature of the axial ligands. The TGA behaviors of two compounds 1 and 2 are also significantly affected by the nature of the axial ligands.

Channels with ordered water and bipyridine mol-ecules in the porous coordination polymer {[Cu(SiF6)(C10H8N2)2]·2C10N2H8·5H2O} n.

The coordination polymer {[Cu(SiF6)(C10H8N2)2]·2C10H8N2·5H2O} n , systematic name: poly[[bis-(μ2-4,4'-bi-pyridine)(μ2-hexa-fluorido-silicato)copper(II)] 4,4'-bi-pyridine disolvate penta-hydrate], contains pores which are filled with water and 4,4'-bi-pyridine mol-ecules. As a result of the presence of these ordered species, the framework changes its symmetry from P4/mmm to P21/c. The 4,4'-bi-pyridine guest mol-ecules form chains inside the 6.5 × 6.9 Å pores parallel to [100] in which the mol-ecules inter-act through π-π stacking. Ordered water mol-ecules form infinite hydrogen-bonded chains inside a second pore system (1.6 × 5.3 Å free aperture) perpendicular to the 4,4'-bi-pyridine channels.

Supramolecular architecture and regularities of crystal packings of the heterocyclic gold(III) iminatoamine complexes

The regularities of the structural organization of crystal packings in the gold(III) iminatoamine complexes [Au(C9H19N4]Y2 (Y = I, ClO4, PF6) and [Au(C9H18N4X)](ClO4)2 (X = Cl, Br) are revealed. The 3D supramolecular architecture of the crystalline lattice of the complexes is characterized by common structural units: 1D cation-anion ribbons (pseudoribbons), cation-cation stacks, and cation-anion columns that form cation-anion layers. The structures of the complexes include infinite chains of hydrogen bonds or contacts containing bridging atoms and closed rings of different dimensionality. The determining role in the topological pattern of packings of the complexes belongs to the planar character of the cation along with the presence of cis-amino groups in the AuN4 coordination node and methyl groups in the α-position of the sixmembered delocalized ring. The halogenation of the iminate rings of the ligands does not result in a substantial change in the architecture of the packings.

N-(2-Chloro-eth-yl)morpholine-4-carbox-amide.

The title compound, C7H13ClN2O2, synthesized by the reaction of 2-chloro­ethyl iso­cyanate and morpholine, crystallizes with four molecules in the asymmetric unit, which have similar conformations and comprise two pairs each related by approximate non-crystallographic inversion centres. Two of them have a modest orientational disorder of the 2-chloro­ethyl fragments [occupancy ratio of 0.778 (4):0.222 (4)]. In the crystal, mol­ecules are linked by N—H⋯O=C hydrogen bonds, forming three crystallographically different kinds of infinite hydrogen-bonded chains extending along [001].

2-(3-Methoxyphenyl)-1,3-dihydro-1,3,2-benzodiazaborole

The title compound, C13H13BN2O, is one in a series of 1,3,2-benzodiaza­boroles featuring a 2-meth­oxy­phenyl substitution at the 2-position in the nitro­gen–boron heterocyle. The dihedral angle between the mean planes of the benzodiaza­borole and 2-meth­oxy­phenyl ring systems is 21.5 (1)°. There is an inter­molecular hydrogen bond between one of the NH groups and the meth­oxy O atom. This hydrogen bond leads to an infinite hydrogen-bonded chain colinear with the a axis.

Bis(tetraphenylphosphonium) tetracyanidonitridochromate(V) dihydrate

In the title compound, (C24H20P)2[Cr(CN)4(N)]·2H2O, the complex anion exhibits a square-based pyramidal geometry around the central CrV atom, which is coordinated by a nitride ligand in the apical position and by four cyanide ligands in the equatorial plane. The chromium atom is located 0.4493 (13) Å out of the plane formed by the ligating C atoms of the cyanide ligands. The water mol­ecules of crystallization form inter­molecular O—H⋯N hydrogen bonds to the N atoms of two cyanide ligands of neighbouring complex anions, forming an infinite hydrogen-bonded chain parallel to [011] of water mol­ecules and [Cr(N)(CN)4]2− anions. The terminal nitride ligands are not engaged in inter­molecular inter­actions.

Comparative physical, mechanical and crystallographic properties of a series of gemfibrozil salts

Understanding the impact of the counterion on the properties of an acidic or basic drug may influence the choice of salt form, especially for less potent drugs with a high drug load per unit dose. The aim of this work was to determine the influence of the hydrogen bonding potential of the counterion on the crystal structure of salts of the poorly soluble, poorly compressible, acidic drug gemfibrozil and to correlate these with mechanical properties. Compacts of the parent drug and the salts were used to determine Young's modulus of elasticity using beam bending tests. Crystal structures were determined previously from X-ray powder diffraction data. The free acid, tert-butylamine, 2-amino-2-methylpropan-1-ol and 2-amino-2-methylpropan-1,3-diol salts had a common crystal packing motif of infinite hydrogen-bonded chains with cross-linking between pairs of adjacent chains. The tromethamine (trsi) salt, with different mechanical properties, had a two-dimensional sheet-like network of hydrogen bonds, with slip planes, forming a stiffer compact. The type of counter ion is important in determining mechanical properties and could be selected to afford slip and plastic deformation.

Chirality influence on the aggregation of methyl mandelate

The methyl ester of mandelic acid is investigated by a wide range of techniques to unravel its aggregation pattern and the influence of relative chirality of the aggregating monomers. Matrix isolation confirms that a single monomer conformation prevails. The electronic spectrum of the dimers is strongly affected by the relative monomer chirality. Vibrational effects are more subtle and can be explained in terms of the most stable homo- and heteroconfigurational dimer structures, when compared to results of MP2 and DFT-D computations. Selective IR/UV double resonance techniques and wide-band FTIR spectroscopy provide largely consistent spectroscopic fingerprints of the chirality discrimination phenomena. The dominant homochiral dimer has two intermolecular O–H⋯OC hydrogen bonds whereas the more strongly bound heterochiral dimer involves only one such hydrogen bond. This is a consequence of the competition between dispersion and intramolecular or intermolecular hydrogen bonding. Aromatic interactions also play a role in trimers and larger clusters, favoring homochiral ring arrangements. Analogies and differences to the well-investigated methyl lactate system are highlighted. Bulk phases show a competition between different hydrogen bond patterns. The enantiopure, racemic, and 3 : 1 crystals involve infinite hydrogen-bonded chains with different arrangements of the aromatic groups. They exhibit significantly different volatility, the enantiopure compound being more volatile than the racemic crystal. The accumulated experimental and quantum-chemical evidence turns methyl mandelate into a model system for the role of competition between dispersion forces and hydrogen bond interactions in chirality discrimination.

Tetramethylammonium dihydrogen phosphate hemihydrate

In the crystal structure of the title compound, C4H12N+·H2PO4 −·0.5H2O, the anions form an infinite hydrogen-bonded chain along the [10] direction. The anion chains are connected by water mol­ecules, which lie on crystallographic twofold rotation axes, through O—H⋯O hydrogen bonds. These hydrogen bonds are almost perpendicular to the other hydrogen bonds which create an assembled structure of anions. In addition, C—H⋯O hydrogen bonds between anions and cations are observed.

Diverse and Yet Unified: A Comparative Study of the Supramolecular Assemblies of Three Diastereomeric Perhydro‐2,3,4a,6,7,8a‐naphthalenehexols

AbstractSelf‐assemblies of three crystalline perhydro‐2,3,4a,6,7,8a‐naphthalenehexols 3–5, all constructed on a trans‐decalin framework, were compared with each other and to that of their diastereomeric all axial hydroxy sibling 2, which was previously reported. The presence of the peripheral equatorial OH groups in 3–5 severs, to varying extents, the end‐to‐end intramolecular O–H···O hydrogen‐bonding chain linking the 1,3‐diaxial hydroxy groups on both faces of hexol 2. Hence, the crystal packing in 3–5 deviates from the simple qualitative model proposed and observed in 2. Though complex and seemingly individualistic upon a cursory glance, the supramolecular assemblies of all three hexols underscore two primary concepts of O–H···O hydrogen bonding, namely, maximization of the total number of hydrogen bonds per molecule and maximization of O–H···O hydrogen‐bond cooperativity by forming as many finite and infinite chains of hydrogen bonds as possible.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Self-assembly of metal(II) tetraaza macrocyclic complexes with cyclobutane-1-carboxylic acid-1-carboxylate ligand linked by hydrogen bond

The reaction of [M(L)]Cl2 · 2H2O (M = Ni2+ and Cu2+, L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane) with 1,1-cyclobutanedicarboxylic acid (H2-cbdc) generates 1D and 2D hydrogen-bonded infinite chains [Ni(L)(H-cbdc−)2] (1) and [Cu(L)(H-cbdc−)2] (2). (H-cbdc− = cyclobutane-1-carboxylic acid-1-carboxylate). These complexes have been characterized by X-ray crystallography, spectroscopy, and cyclic voltammetry. The crystal structure of 1 shows a distorted octahedral coordination geometry around the nickel(II) ion, with four secondary amines and two oxygen atoms of the H-cbdc− ligand at the trans position. In 2, the coordination environment around the central copper(II) ion shows a Jahn–Teller distorted octahedron with four Cu–N bonds and two long Cu–O distances. The cyclic voltammogram of the complexes undergoes two one-electron waves corresponding to MII/MIII and MII/MI processes. The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature of the axial H-cbdc− ligand.

One-dimensional hydrogen-bonded infinite chains composed of nickel(II) and copper(II) tetraaza macrocyclic complexes with cyclopropane-1-carboxylic acid-1-carboxylate ligand

The reaction of [M(L)]Cl2 · 2H2O (M = Ni2+ and Cu2+, L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane) with 1,1-cyclopropanedicarboxylic acid (H2-cpdc) generates one-dimensional hydrogen-bonded infinite chains [Ni(L)(H-cpdc)2] (1) and [Cu(L)(H-cpdc)2] (2) (H-cpdc = cyclopropane-1-carboxylic acid-1-carboxylate). These complexes have been characterized by X-ray crystallography, spectroscopy, and cyclic voltammetry. The crystal structures of (1) and (2) show a distorted octahedral coordination geometry around the metal ion, with four secondary amines and two oxygen atoms of the H-cpdc ligand at the trans position. Complexes (1) and (2) display the one-dimensional hydrogen-bonded infinite chains. The cyclic voltammogram of the complexes display two one-electron waves corresponding to MII/MIII and MII/MI processes. The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature of the axial H-cpdc ligand.