Bis(6‐thioxo‐1,6‐dihydro­purinium) tetra­chloro­zincate(II)

The title salt, (C₅H₅N₄S)₂[ZnCl₄], consists of two 6‐thioxo‐1,6‐dihydro­purinium (6mpH₂⁺) cations (A and B) and a tetra­chloro­zincate anion, which are held together by N—H⋯Cl and C—H⋯Cl inter­actions. There is an anion–π inter­action between one Cl atom of the [ZnCl₄]⁻ anion and the pyrimidine ring of the 6mpH₂⁺(B) cation. Inter­molecular π–π stacking inter­actions allow 6mpH₂⁺(A) cations to form anti­parallel pairs. One inter­esting structural feature is the double N—H⋯N inter­molecular hydrogen bonds between two 6mpH₂⁺(A) cations. This kind of inter­action, mimicking that of natural nucleobases, can be very valuable in designing new therapeutic purine derivatives.     

Hydrogen bonding in dibromo[2‐(dimethyl­aminomethyl)phenyl][2‐(dimethylammoniomethyl)phenyl]tin(IV) tetra­bromo­[2‐(dimethyl­aminomethyl)phenyl]­tin(IV)

The mol­ecular structure of the title compound, [SnBr₂(C₉H₁₂N)(C₉H₁₃N)][SnBr₄(C₉H₁₂N)], consists of a dibromo­bis[2‐(dimethyl­aminomethyl)phenyl][2‐dimethylammoniomethyl)phenyl]tin(IV) cation and a tetra­bromo­[2‐(dimethyl­aminomethyl)phenyl]tin(IV) anion. As a result of strong intra­molecular N→Sn inter­actions, distorted trigonal–bipy­ramidal and octa­hedral coordination geometries are established for the metal centres of the diorganotin(IV) and monoorganotin(IV) fragments, respectively. The cation and anion are linked together by two Br⋯H contacts, while three additional similar contacts result in a dimeric fragment which repeats in a two‐dimensional supra­molecular arrangement.     

Secondary inter­actions in two related terphenyl derivatives: 2′,5′‐dimethyl‐p‐terphenyl and 2′,5′‐bis­(bromo­meth­yl)‐p‐terphen­yl

In 2′,5′‐dimethyl‐p‐terphenyl, C₂₀H₁₈, which displays pseudosymmetry (the true space group is Pna2₁, but less satisfactory refinement can also be achieved in Pbcn), the mol­ecules are linked into chains by two short C—H⋯π inter­actions to the centroid of the central ring. In 2′,5′‐bis­(bromo­meth­yl)‐p‐terphenyl, C₂₀H₁₆Br₂, the polar CH₂Br groups cause mol­ecules to aggregate via C—H⋯Br and Br⋯Br inter­actions, forming a layer structure, in which the phenyl rings project outwards from the central, more polar, region.     

1‐Benzyl‐3,3‐dichloro‐1H‐indol‐2(3H)‐one

The title compound, C₁₅H₁₁Cl₂NO, was synthesized from N‐­benzyl­isatin. The compound crystallizes as stacks of mol­ecules running down the c axis. Mol­ecules within each of these stacks inter­act with each other through π–π and C—H⋯π inter­actions, and inter­act with neighbouring stacks through C—H⋯O inter­actions.     

A hydrogen‐bonded heterodimer of 1‐(4‐hexyloxyphenyl)pyridin‐4(1H)‐one with 4‐cyano­benzoic acid

The two components of the title heterodimer, C₁₇H₂₁NO₂·C₈H₅NO₂, are linked end‐to‐end via O—H⋯O(=C) and C—H⋯O(=C) hydrogen‐bond inter­actions. Additional lateral C—H⋯O inter­actions link the dimers in a side‐by‐side fashion to produce wide infinite mol­ecular ribbons. Adjacent ribbons are inter­connected viaπ–π stacking and C—H⋯π(arene) inter­actions. This structure represents the first evidence of robust hydrogen‐bond formation between the moieties of pyridin‐4(1H)‐one and benzoic acid.     

2,2′‐(Iminodimethylene)bis(1H‐benzimidazolium)(1+) chloride

The title compound, C₁₆H₁₆N₅⁺·Cl⁻ (nbbH⁺·Cl⁻), displays N—H⋯N, N—H⋯Cl and π–π inter­actions in the crystal packing. The Cl⁻ anion is chelated by the nbbH⁺ cation via two N—H⋯Cl hydrogen bonds. Inter‐ion N—H⋯N and N—H⋯Cl hydrogen bonds link ions related by 2₁ screw axes into chains along the c axis. These chains are further linked by glide‐plane operations to generate a three‐dimensional network, which is additionally stabilized by inter­chain π–π inter­actions.     

1‐((E)‐{(1R,2R)‐2‐[(E)‐(2‐Hydr­oxy‐1‐naphth­yl)methyl­eneamino]cyclo­hexyl}iminiometh­yl)naphthalen‐2‐olate: a Schiff base compound having both OH and NH character

The title Schiff base compound, C₂₈H₂₆N₂O₂, possesses both OH and NH tautomeric character in its mol­ecular structure. While the OH side of the compound is described as an inter­mediate state, its NH side adopts a predominantly zwitterionic form. The mol­ecular structure of the compound is stabilized by both N⁺—H⋯O⁻ and O—H⋯N intra­molecular hydrogen bonds. There are two weak C—H⋯O hydrogen bonds leading to polymeric chains of topology C(5) and C(13) running along the b axis of the unit cell. In addition, inter­molecular C—H⋯π inter­actions serve to stabilize the extended structure.     

The perchlorate salt of the novel diprotonated dinucleating ligand 1,3‐bis­{[2‐(2‐pyridinio)eth­yl][2‐(2‐pyrid­yl)eth­yl]amino}benzene

In the title salt, 1,3‐bis­{[2‐(2‐pyridinio)eth­yl][2‐(2‐pyrid­yl)ethyl]amino}benzene diperchlorate dihydrate, C₃₄H₃₈N₆²⁺·2ClO₄⁻·2H₂O, the cation contains two ethyl­pyrid­yl and two ethyl­pyridinium pendant pairs anchored to the two N atoms of 1,3‐phenyl­enediamine. The pyrid­yl and pyridinium N atoms are flanked by a mol­ecule of water through strong hydrogen‐bonding inter­actions [N—H⋯O = 2.762 (6) and 2.758 (6) Å, and O—H⋯N = 2.834 (6) and 2.839 (6) Å]. The water mol­ecules have weak hydrogen‐bonding inter­actions with the perchlorate anions as well. One of the perchlorate anions is severely disordered.     

1‐Acetyl‐3‐ferrocenyl‐5‐methyl‐1H‐pyrazole and 1‐acetyl‐5‐ferrocenyl‐3‐(2‐pyrid­yl)‐1H‐pyrazole

Mol­ecules of 1‐acetyl‐3‐ferrocenyl‐5‐methyl‐1H‐pyrazole, [Fe(C₅H₅)(C₁₁H₁₁N₂O)], form a centrosymmetric dimer generated by a combination of one C—H⋯π(pyrazole) and one C—H⋯π(cyclo­penta­dienyl) inter­action. The dimers are linked by C—H⋯π inter­actions, involving the pyrazole rings as acceptors, into layers parallel to (10). Mol­ecules of 1‐acetyl‐5‐ferrocenyl‐3‐(2‐pyrid­yl)‐1H‐pyrazole, [Fe(C₅H₅)(C₁₅H₁₂N₃O)], are linked by C—H⋯O inter­actions into a chain running in the [010] direction. Two chains of this type passing through each unit cell are connected by O⋯π(pyridyl) inter­actions into an [010] double chain.     

C—H⋯O,C—H⋯π and π–π inter­actions in three benzofuran‐2‐yl ketone derivatives

The mol­ecules of 2‐benzoyl‐1‐benzofuran, C₁₅H₁₀O₂, (I), inter­act through double C—H⋯O hydrogen bonds, forming dimers that are further linked by C—H⋯O, C—H⋯π and π–π inter­actions, resulting in a three‐dimensional supramolecular network. The dihedral angle between the benzo­yl and benzofuran fragments in (I) is 46.15 (3)°. The mol­ecules of bis­(5‐bromo‐1‐benzofuran‐2‐yl) ketone, C₁₇H₈Br₂O₃, (II), exhibit C₂ symmetry, with the carbon­yl group (C=O) lying along the twofold rotation axis, and are linked by a combination of C—H⋯O and C—H⋯π inter­actions and Br⋯Br contacts to form sheets. The stability of the mol­ecular packing in 3‐mesit­yl‐3‐methyl­cyclo­but­yl 3‐methyl­naphtho[1,2‐b]furan‐2‐yl ketone, C₂₈H₂₈O₂, (III), arises from C—H⋯π and π–π stacking inter­actions. The fused naphthofuran moiety in (III) is essentially planar and makes a dihedral angle of 81.61 (3)° with the mean plane of the trimethyl­benzene ring.     

Monoclinic and triclinic concomitant polymorphs of di‐μ‐pyridazine‐1κ2N:2κ2N′‐bis­[(saccharinato)silver(I)]

Crystallization of the title compound, di‐μ‐pyridazine‐1κ²N:2κ²N′‐bis­[(2,3‐dihydro‐3‐oxobenzisosulfonazolato‐κN)silver(I)], [Ag₂(C₇H₄NO₃S)₂(C₄H₄N₂)₂], from acetonitrile yields both monoclinic, (I), and triclinic, (II), polymorphs. In both forms, the silver(I) ions have a slightly distorted trigonal AgN₃ coordination geometry and are doubly bridged by two neutral pyridazine (pydz) ligands, generating a centrosymmetric dimeric structure. The saccharinate (sac) ligands are N‐coordinated. The dihedral angles between the sac and pydz rings are 8.43 (7) and 7.94 (8)° in (I) and (II), respectively, suggesting that the dimeric mol­ecule is nearly flat. The bond geometry is similar in both polymorphs. In (I), the dimers inter­act with each other via aromatic π_sac–π_pydz stacking inter­actions, forming two‐dimensional layers, which are further crosslinked by weak C—H⋯O inter­actions. Compound (II) exhibits similar C—H⋯O and π–π inter­actions, but additional C—H⋯π and π⋯Ag inter­actions help to stabilize the packing of the dimers.     

catena‐Poly[[{4‐bromo‐2‐[2‐(dimethyl­amino)ethyl­imino­methyl]­phenol­ato}­copper(II)]‐μ‐azido]

The title complex, [Cu(C₁₁H₁₄BrN₂O)(N₃)]_n, is an inter­esting azide‐bridged polynuclear copper(II) compound. The Cu^II atom is five‐coordinated in a square‐pyramidal configuration, with one O and two N atoms of one Schiff base and one terminal N atom of a bridging azide ligand defining the basal plane, and another terminal N atom of another bridging azide ligand occupying the axial position. The {4‐bromo‐2‐[2‐(dimethyl­amino)ethyl­imino­meth­yl]phenolato}copper(II) moieties are linked by the bridging azide ligands, forming polymeric chains running along the b axis. Adjacent chains are further linked by weak Br⋯Br inter­actions into a sheet.     

1‐(1‐Amino‐4‐bromo‐9,10‐dioxo‐9,10‐dihydro­anthracen‐2‐ylcarbon­yl)‐1,3‐dicyclo­hexyl­urea

In the title compound, C₂₈H₃₀BrN₃O₄, the mol­ecules are linked by C—H⋯Br and N—H⋯O hydrogen bonds into one‐dimensional chains, which are arranged into a three‐dimensional network through a combination of C—H⋯O hydrogen bonds and two kinds of π–π inter­actions between the benzene rings of the anthraquinone units.     

Dichloro­(O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid‐κ2N,N′)copper(II)

In the title compound, [CuCl₂(C₉H₁₂N₂O)], the Cu^II atom is coordinated by two Cl⁻ anions and two N atoms of one O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid mol­ecule in a slightly distorted square‐planar geometry, with Cu—N distances of 2.0483 (17) and 1.9404 (18) Å, and Cu—Cl distances of 2.2805 (10) and 2.2275 (14) Å. In addition, each Cu^II atom is connected by one Cl⁻ anion and the Cu^II atom from a neighbouring mol­ecule, with Cu⋯Cl and Cu⋯Cu distances of 2.9098 (13) and 3.4022 (12) Å, respectively, and, therefore, a centrosymmetric dimer is formed. Adjacent mol­ecular dimers are connected by π–π stacking inter­actions between pyridine rings to form a zigzag mol­ecular chain. The mol­ecular chains are also enforced by N—H⋯Cl and C—H⋯Cl inter­actions.     

4‐(4‐Fluoro‐3‐phenoxy­phen­yl)‐6‐(4‐fluoro­phen­yl)‐2‐oxo‐1,2‐dihydro­pyridine‐3‐carbonitrile and the 6‐(4‐methyl­phen­yl)‐ analogue

The crystal structures of the title compounds, viz. C₂₄H₁₄F₂N₂O₂, (I), and C₂₅H₁₇FN₂O₂, (II), respectively, have been determined in order to unravel the role of an ordered F atom in generating stable supra­molecular assemblies. On changing the substitution from fluorine to a methyl group, C—H⋯F inter­actions are replaced by C—H⋯π inter­actions, revealing the importance of such weak inter­actions when present alongside N—H⋯O and C—H⋯O hydrogen bonds. The dihedral angle between the planes of the 4‐fluoro­phenyl ring and the pyridine ring is 26.8 (1)° in (I), while that between the planes of the 4‐methyl­phenyl and pyridine rings is 29.5 (1)° in (II).     

4,4′‐Butane‐1,4‐diylbis[3‐ethyl‐1H‐1,2,4‐triazol‐5(4H)‐one] and 4‐hydr­oxy‐3‐n‐prop­yl‐1H‐1,2,4‐triazol‐5(4H)‐one

The title compounds, C₁₂H₂₀N₆O₂, (I), and C₅H₉N₃O₂, (II), display the characteristic features of 1,2,4‐triazole derivatives. Compound (I) lies about an inversion centre which is at the mid‐point of the central C—C bond. Compound (II) also contains a planar 1,2,4‐triazole ring but differs from (I) in that it has a hydr­oxy group attached to the ring. Mol­ecules of (I) are held together in the crystal structure by inter­molecular N—H⋯O contacts and by weak π–π stacking inter­actions between the 1,2,4‐triazole moieties. Compound (II) contains inter­molecular O—H⋯O and N—H⋯O hydrogen bonds.     

6‐Phenyl‐3‐(4‐pyrid­yl)‐1,2,4‐triazolo[3,4‐b][1,3,4]thia­diazole

The title compound, C₁₄H₉N₅S, has been synthesized and characterized both spectroscopically and structurally. The triazolo–thia­diazole system, the pyridine ring and the phenyl ring are all planar. The plane of the triazolo–thia­diazole system forms dihedral angles of 1.53 (13) and 7.55 (12)° with the planes of the pyridine and phenyl rings, respectively. In the mol­ecule, there are two intra­molecular inter­actions of types C—H⋯N and C—H⋯S. Inter­molecular C—H⋯N inter­actions involving a phenyl CH group and a triazole N atom lead to the formation of a one‐dimensional chain. In the crystal structure, two types of π–π inter­actions affect the packing of the mol­ecules. In addition, there are inter­molecular non‐bonded S⋯N contacts of 2.870 (2) Å, which may cause steric hindrance.     

Three (E)‐2‐[(bromo­phen­yl)imino­meth­yl]‐4‐methoxy­phenols

The title compounds, (E)‐2‐[(2‐bromo­phenyl)imino­methyl]‐4‐methoxy­phenol, C₁₄H₁₂BrNO₂, (I), (E)‐2‐[(3‐bromo­phenyl)­imino­methyl]‐4‐methoxy­phenol, C₁₄H₁₂BrNO₂, (II), and (E)‐2‐[(4‐bromo­phenyl)imino­methyl]‐4‐methoxy­phenol, C₁₄H₁₂BrNO₂, (III), adopt the phenol–imine tautomeric form. In all three structures, there are strong intra­molecular O—H⋯N hydrogen bonds. Compound (I) has strong inter­molecular hydrogen bonds, while compound (III) has weak inter­molecular hydrogen bonds. In addition to these inter­molecular inter­actions, C—H⋯π inter­actions in (I) and (III), and π–π inter­actions in (I), play roles in the crystal packing. The dihedral angles between the aromatic rings are 15.34 (12), 6.1 (3) and 39.2 (14)° for (I), (II) and (III), respectively.     

Tetra­aqua­(7‐hydroxy‐5‐oxidoflavone‐6‐sulfonato‐κ2O4,O5)nickel(II) dimethyl­formamide solvate monohydrate

In the title compound, [Ni(C₁₅H₈O₇S)(H₂O)₄]·C₃H₇NO·H₂O, the Ni^II cation is chelated by a 7‐hydroxy‐5‐oxidoflavone‐6‐sulfonate ligand through one oxide and one carbonyl O atom, and the sixfold coordination is completed by four aqua ligands. Individual mol­ecules are linked into hydrogen‐bonded dimers by way of five pairs of O—H⋯O hydrogen bonds. These dimers, in turn, determine a three‐dimensional supra­molecular arrangement through a variety of inter­dimeric inter­actions, such as O—H⋯O, C—H⋯O and π–π stacking.     

3,4‐Di‐2‐pyridyl‐1,2,5‐oxadiazole and its perchlorate salt

In 3,4‐di‐2‐pyridyl‐1,2,5‐oxadiazole (dpo), C₁₂H₈N₄O, each mol­ecule resides on a twofold axis and inter­acts with eight neighbours via four C—H⋯N and four C—H⋯O inter­actions to generate a three‐dimensional hydrogen‐bonded architecture. In the perchlorate analogue, 2‐[3‐(2‐pyrid­yl)‐1,2,5‐oxadiazol‐4‐yl]pyridinium perchlorate, C₁₂H₉N₄O⁺·ClO₄⁻ or [Hdpo]ClO₄, the [Hdpo]⁺ cation is bisected by a crystallographic mirror plane, and the additional H atom in the cation is shared by the two pyridyl N atoms to form a symmetrical intra­molecular N⋯H⋯N hydrogen bond. The cations and perchlorate anions are linked through C—H⋯O hydrogen bonds and π–π stacking inter­actions to form one‐dimensional tubes along the b‐axis direction.