Constructor graph description of hydrogen bonding in a supramolecular assembly of (3,5‐dimethyl‐1H‐pyrazol‐4‐ylmethyl)isopropylammonium chloride monohydrate

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.     

2‐Ethyl‐1‐[5‐(4‐methylphenyl)pyrazol‐3‐yl]‐3‐(thiophene‐2‐carbonyl)isothiourea: molecular ribbons containing three types of hydrogen‐bonded ring

The title compound, C₁₈H₁₈N₄OS₂, was prepared by reaction of S,S‐diethyl 2‐thenoylimidodithiocarbonate with 5‐amino‐3‐(4‐methylphenyl)‐1H‐pyrazole using microwave irradiation under solvent‐free conditions. In the molecule, the thiophene unit is disordered over two sets of atomic sites, with occupancies of 0.814 (4) and 0.186 (4), and the bonded distances provide evidence for polarization in the acylthiourea fragment and for aromatic type delocalization in the pyrazole ring. An intramolecular N—H...O hydrogen bond is present, forming an S(6) motif, and molecules are linked by N—H...O and N—H...N hydrogen bonds to form a ribbon in which centrosymmetric R₂²(4) rings, built from N—H...O hydrogen bonds and flanked by inversion‐related pairs of S(6) rings, alternate with centrosymmetric R₂²(6) rings built from N—H...N hydrogen bonds.     

trans‐Diaquabis(3‐hydroxybenzoato‐κO1)bis(nicotinamide‐κN1)copper(II)

The title compound, [Cu(C₇H₅O₃)₂(C₆H₆N₂O)₂(H₂O)₂], is a two‐dimensional hydrogen‐bonded supramolecular complex. The Cu^II ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridine N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R₂²(4), R₂²(8) and R₂²(15) rings which lead to one‐dimensional polymeric chains. An extensive two‐dimensional network of N—H...O and O—H...O hydrogen bonds and C—H...π interactions are responsible for crystal stabilization.     

Diaquabis(4‐fluorobenzoato‐κO)bis(nicotinamide‐κN)cobalt(II)

The title compound, [Co(C₇H₄FO₂)₂(C₆H₆N₂O)₂(H₂O)₂], is a three‐dimensional hydrogen‐bonded supramolecular complex. The Co^II ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R₃²(6), R₂²(12) and R₂²(16) rings, which lead to two‐dimensional chains. An extensive three‐dimensional network of C—H...F, N—H...O and O—H...O hydrogen bonds and π–π interactions are responsible for crystal stabilization.     

Polymorphism in 2‐(4‐hydroxy‐2,6‐dimethylanilino)‐5,6‐dihydro‐4H‐1,3‐thiazin‐3‐ium chloride

Details of the structures of two conformational polymorphs of the title compound, C₁₂H₁₇N₂OS⁺·Cl⁻, are reported. In form (I) (space group P), the two N—H groups of the cation are in a trans conformation, while in form (II) (space group P2₁/c), they are in a cis arrangement. This results in different packing and hydrogen‐bond arrangements in the two forms, both of which have extended chains lying along the a direction. In form (I), these chains are composed of centrosymmetric R₄²(18) (N—H...Cl and O—H...Cl) hydrogen‐bonded rings and R₂²(18) (N—H...O) hydrogen‐bonded rings. In form (II), the chains are formed by centrosymmetric R₄²(18) (N—H...Cl and O—H...Cl) hydrogen‐bonded rings and by R₄²(12) (N—H...Cl) hydrogen‐bonded rings.     

4‐Iodo­anilinium 3‐nitro­phthalate(1–): tripartite sheets built from O—H...O and N—H...O hydrogen bonds

In the title compound, 4‐iodoanilinium 2‐carboxy‐6‐nitrobenzoate, C₆H₇IN⁺·C₈H₄NO₆⁻, the anions are linked by an O—H...O hydrogen bond [H...O = 1.78 Å, O...O = 2.614 (3) Å and O—H...O = 171°] into C(7) chains, and these chains are linked by two two‐centre N—H...O hydrogen bonds [H...O = 1.86 and 1.92 Å, N...O = 2.700 (3) and 2.786 (3) Å, and N—H...O = 153 and 158°] and one three‐centre N—H...(O)₂ hydrogen bond [H...O = 2.02 and 2.41 Å, N...O = 2.896 (3) and 2.789 (3) Å, N—H...O = 162 and 105°, and O...H...O = 92°], thus forming sheets con­taining R(6), R(8), R(13) and R(18) rings.     

N,N′‐Dicyclohexyl‐N‐[4‐(1H‐indol‐3‐yl)butanoyl]urea

The title compound, C₂₅H₃₅N₃O₂, is a novel urea derivative. Pairs of intermolecular N—H...O hydrogen bonds join the molecules into centrosymmetric R₂²(12) and R₂²(18) dimeric rings, which are alternately linked into one‐dimensional polymeric chains along the [010] direction. The parallel chains are connected via C—H...O hydrogen bonds to generate a two‐dimensional framework structure parallel to the (001) plane. The title compound was also modelled by solid‐state density functional theory (DFT) calculations. A comparison of the molecular conformation and hydrogen‐bond geometry obtained from the X‐ray structure analysis and the theoretical study clearly indicates that the DFT calculation agrees closely with the X‐ray structure.     

5‐Methyl‐N‐[2‐nitro‐4‐(trifluoromethyl)phenyl]‐1H‐pyrazole‐3‐amine: a chain of hydrogen‐bonded R22(6) and R22(16) rings

The molecular skeleton of the title compound, C₁₁H₉F₃N₄O₂, is almost planar and exhibits a polarized (charge‐separated) electronic structure in the nitroaniline portion. Molecules are linked by N—H...N and C—H...O hydrogen bonds to form a chain in which centrosymmetric R₂²(6) and R₂²(16) rings alternate.     

4‐Amino‐3,5‐diethyl‐4H‐1,2,4‐triazole at 100 K: chains of edge‐fused R44(10) and R44(20) rings

The title compound, C₆H₁₂N₄, has four crystallographically independent molecules in the asymmetric unit. Intermolecular N—H...N hydrogen bonds involving amino groups and triazole N atoms form a three‐dimensional framework involving R₄⁴(10) and R₄⁴(20) rings. The hydrogen bonding is supported by weak C—H...π interactions.     

N‐Cyclo­hexyl‐2‐[5‐(4‐pyridyl)‐4‐(p‐tolyl)‐4H‐1,2,4‐triazol‐3‐yl­sulfanyl]­acetamide dihydrate

In the title compound, C₂₂H₂₅N₅OS·2H₂O, the mol­ecules are stacked in columns running along the b axis. In this arrangemant, the mol­ecules are linked to each other by a combination of one two‐centre N—H⋯O hydrogen bond and four two‐centre O—H⋯O hydrogen bonds containing two types of ring motif, viz.R₄⁴(10) and R₃³(11). In the crystal structure, centrosymmetric π–π inter­actions between the triazole rings, with a distance of 3.691 (2) Å between the ring centroids, also affect the packing of the mol­ecules.     

2,4‐Dimethyl‐1,3‐thiazole‐5‐carboxylic acid: an X‐ray structural study at 100 K and Hirshfeld surface analysis

The crystal structure of the title thiazolecarboxylic acid derivative, C₆H₇NO₂S, (I), has been determined from single‐crystal X‐ray analysis at 100 K. In the crystal packing, an interplay of O—H...N and C—H...O hydrogen bonds connects the molecules to form C(6)R₂²(8) polymeric chains, which are further linked via weak C—H...O hydrogen bonds into a two‐dimensional supramolecular framework. The relative contributions of different interactions to the Hirshfeld surface in (I) and a few related thiazolecarboxylic acid derivatives indicate that the H...H, N...H and O...H contacts can account for about 50–70% of the total Hirshfeld surface area in this class of compound.     

Two derivatives of 1,5‐disubstituted tetrazoles: 1‐(4‐nitrophenyl)‐1H‐tetrazol‐5‐amine and {(E)‐[1‐(4‐ethoxyphenyl)‐1H‐tetrazol‐5‐yl]iminomethyl}dimethylamine

The geometric features of 1‐(4‐nitrophenyl)‐1H‐tetrazol‐5‐amine, C₇H₆N₆O₂, correspond to the presence of the essential interaction of the 5‐amino group lone pair with the π system of the tetrazole ring. Intermolecular N—H...N and N—H...O hydrogen bonds result in the formation of infinite chains running along the [110] direction and involve centrosymmetric ring structures with motifs R₂²(8) and R₂²(20). Molecules of {(E)‐[1‐(4‐ethoxyphenyl)‐1H‐tetrazol‐5‐yl]iminomethyl}dimethylamine, C₁₂H₁₆N₆O, are essentially flattened, which facilitates the formation of a conjugated system spanning the whole molecule. Conjugation in the azomethine N=C—N fragment results in practically the same length for the formal double and single bonds.     

trans‐Diaquabis(nicotinamide‐κN)bis(salicylato‐κO)cobalt(II)

The title compound, [Co(C₇H₅O₃)₂(C₆H₆N₂O)₂(H₂O)₂], forms a three‐dimensional hydrogen‐bonded supramolecular structure. The Co^II ion is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R₂²(8), R₂²(12) and R₂²(14) rings, which lead to two‐dimensional chains. An extensive three‐dimensional supramolecular network of C—H...O, N—H...O and O—H...O hydrogen bonds and C—H...π interactions is responsible for crystal structure stabilization. This study is an example of the construction of a supramolecular assembly based on hydrogen bonds in mixed‐ligand metal complexes.     

3‐{[4‐Amino‐6‐methoxy‐2‐(methylsulfanyl)pyrimidin‐5‐yl]amino}‐1,2′‐biindenylidene‐1′,3′‐dione dimethyl sulfoxide solvate: π‐stacked sheets of hydrogen‐bonded chains of edge‐fused rings

In the title compound, C₂₄H₁₈N₄O₃S·C₂H₆OS, the biindenylidene component shows evidence of polarization of the electronic structure. The dimethyl sulfoxide solvent molecules are disordered over two sites, and they are linked to the biindenylidenedione components via N—H...O and C—H...O hydrogen bonds. A combination of N—H...N and N—H...O hydrogen bonds links the nonsolvent components into a chain of edge‐fused centrosymmetric R₂²(8) and R₂²(22) rings, and these chains are linked into sheets by a single aromatic π–π stacking interaction.     

(E)‐N′‐[5‐Chloro‐3‐methoxy‐2‐(4‐methylphenylsulfonyloxy)benzylidene]isonicotinohydrazide acetic acid solvate: hydrogen‐bonded network of alternating R44(42), R55(33) and R66(40) rings

In the title compound, C₂₁H₁₈ClN₃O₅S·C₂H₄O₂, a combination of O—H...O, N—H...O, C—H...O and C—H...N hydrogen bonds links the components into a complex network containing alternating R₄⁴(42), R₅⁵(33) and R₆⁶(40) rings.     

(S)‐5‐Benzylimidazolidine‐2,4‐dione monohydrate

The crystal structure of the title compound, C₁₀H₁₀N₂O₂·H₂O, also known as l ‐5‐benzylhydantoin monohydrate, is described in terms of two‐dimensional supramolecular arrays built up from infinite chains assembled via N—H...O and O—H...O hydrogen bonds among the organic molecules and solvent water molecules, with graph‐set R³₃(10)C(5)C²₂(6). The hydrogen‐bond network is reinforced by stacking of the layers through C—H...π interactions.     

5‐Amino‐3‐methyl‐1‐phenyl‐1H‐pyrazole‐4‐carbaldehyde hemihydrate: a polarized electronic structure within hydrogen‐bonded sheets of R108(34) rings

In the title compound, C₁₁H₁₁N₃O·0.5H₂O, the water molecule lies across a twofold rotation axis in the space group Pbcn. The bond distances in the organic component provide evidence for polarization of the electronic structure. The molecular components are linked into puckered sheets of R₁₀⁸(34) rings by a combination of O—H...N and N—H...O hydrogen bonds; adjacent sheets are weakly linked by an aromatic π–π stacking interaction. Comparisons are made with some fused‐ring analogues.     

2,5‐Dicarboxy­anilinium chloride monohydrate

The title compound, C₈H₈NO₄⁺·Cl⁻·H₂O, is the chloro­hydrated form of 2‐amino­benzene‐1,4‐dicarboxylic acid, the basic crystal structure of which is still not known. Mol­ecules are linked by classical N—H⋯O, O—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds, mainly along the mol­ecular plane, into sheets built by unusual R₆⁴(26), R₆⁴(22) and R₄³(22) rings. The stacking between layers is stabilized by another N—H⋯Cl hydrogen bond and by π–π inter­actions between aromatic rings facing each other.     

Optical properties of (Z)‐2‐(2‐phenylhydrazinylidene)acenaphthen‐1(2H)‐one: a potential electron donor in organic solar cells

Electron‐donating molecules play an important role in the development of organic solar cells. (Z )‐2‐(2‐Phenylhydrazinylidene)acenaphthen‐1(2H )‐one (PDAK), C₁₈H₁₂N₂O, was synthesized by a Schiff base reaction. The crystal structure shows that the molecules are planar and are linked together forming `face‐to‐face' assemblies held together by intermolecular C—H…O, π–π and C—H…π interactions. PDAK exhibits a broadband UV–Vis absorption (200–648 nm) and a low HOMO–LUMO energy gap (1.91 eV; HOMO is the highest occupied molecular orbital and LUMO is the lowest unoccupied molecular orbital), while fluorescence quenching experiments provide evidence for electron transfer from the excited state of PDAK to C₆₀. This suggests that the title molecule may be a suitable donor for use in organic solar cells.     

Methyl 4‐amino‐2,3‐dihydro‐6‐methoxy‐1,3‐dioxo‐1H‐pyrrolo[3,4‐c]pyridine‐7‐carboxylate forms hydrogen‐bonded sheets built from R22(8) and R66(42) rings

In the title compound, C₁₀H₉N₃O₅, which was formed by the reaction of 6‐amino‐2‐methoxy‐4(3H)‐pyrimidinone with di­methyl acetyl­enedi­carboxyl­ate, the mol­ecules are linked by N—H?O hydrogen bonds [N?O 2.8974 (15) and 3.0300 (15) Å, and N—H?O 165 and 174°] into planar sheets built from alternating R₂²(8) and R₆⁶(42) rings.