Bis­[bis­(pyrimidin‐2‐yl‐κN)­amine](dicyan­amido‐κN1)(tri­fluoro­methanesulfonato‐κO)copper(II) ethanol hemisolvate forms a hydrogen‐bonded chain

In the crystal structure of [Cu(CF₃SO₃)(C₂N₃)(C₈H₇N₅)₂]·0.5C₂H₆O, the Cu^II atom adopts a distorted octahedral geometry, with the basal plane formed by two N atoms of one dipyrimidinyl­amine ligand, one N atom of the second pyrimidine ligand and a nitrile N atom of the dicyan­amide anion [Cu—N = 1.972 (2)–2.021 (2) Å]. The apical positions are occupied by an N atom of the second ligand [Cu—N = 2.208 (2) Å], and an O atom of the tri­fluoro­methane­sulfonate anion [Cu—O = 2.747 (2) Å] at a semi‐coordination distance. Pairs of inversion‐related N—H⋯N hydrogen bonds of the so‐called Watson–Crick type, augmented by two C—H⋯N contacts, link adjacent complexes into an infinite one‐dimensional chain running in the [101] direction.     

Hydrogen bonding and π–π stacking in methyl­aminium 4′,7‐dihydroxy­isoflavone‐3′‐sulfonate dihydrate and hexa­aqua­iron(II) bis­(4′,7‐diethoxy­isoflavone‐3′‐sulfonate) tetra­hydrate

In methyl­aminium 4′,7‐dihydroxy­isoflavone‐3′‐sulfonate dihydrate, CH₆N⁺·C₁₅H₉O₇S⁻·2H₂O, 11 hydrogen bonds exist between the methyl­aminium cations, the iso­flavone‐3′‐sulfonate anions and the solvent water mol­ecules. In hexa­aqua­iron(II) bis­(4′,7‐diethoxy­isoflavone‐3′‐sulfonate) tetra­hydrate, [Fe(H₂O)₆](C₁₉H₁₇O₇S)₂·4H₂O, 12 hydrogen bonds exist between the centrosymmetric [Fe(H₂O)₆]²⁺ cation, the isoflavone‐3′‐sulfonate anions and the solvent water mol­ecules. Additional π–π stacking inter­actions generate three‐dimensional supramolecular structures in both compounds.     

Hydro­gen bonding in ethyl­ene­di­ammonium bis­(hydrogen malonate) mono­hydrate

In the title compound, C₂H₁₀N₂²⁺·2C₃H₃O₄^?·H₂O, the hydrogen malonate anion has an intramolecular O—H?O hydrogen bond of 2.430 (2) Å. The water mol­ecule lies on a twofold axis and connects the anions into pairs through hydrogen bonds of 2.734 (1) Å. The ethyl­enedi­ammonium cation lies across an inversion centre. Each of the ammonium protons is involved in hydrogen bonding to an anion or a water mol­ecule [N?O 2.815 (2)–2.875 (2) Å].     

Hydrogen‐bonded bilayers in ­piperazinium(2+) bis(mandelate) bis(methanol) solvate

In the title compound, C₄H₁₂N₂²⁺·2C₈H₇O₃^?·2CH₄O, the cations lie across centres of inversion and are disordered over two orientations with equal occupancy; there are equal numbers of (R)‐ and (S)‐mandelate anions present (mandelate is α‐hydroxy­benzene­acetate). The anions and the neutral water mol­ecules are linked by O—H?O hydrogen bonds [O?O 2.658 (3) and 2.682 (3) Å, and O—H?O 176 and 166°] into deeply folded zigzag chains. Each orientation of the cation forms two symmetry‐related two‐centre N—H?O hydrogen bonds [N?O 2.588 (4) and 2.678 (4) Å, and N—H?O 177 and 171°] and two asymmetric, but planar, three‐centre N—H?(O)₂ hydrogen bonds [N?O 2.686 (4)–3.137 (4) Å and N—H?O 137–147°], and by means of these the cations link the anion/water chains into bilayers.     

The salt‐type 1:2 adduct of meso‐5,5,7,12,12,14‐hexa‐C‐methyl‐1,4,8,11‐tetraazacyclotetradecane (tet‐a) and 5‐nitroisophthalic acid forms a hydrogen‐bonded sheet ­structure containing two configur­ational isomers of [(tet‐a)H2]2+

The title compound, meso‐5,7,7,12,14,14‐hexa­methyl‐4,11‐di­aza‐1,8‐diazo­nia­cyclo­tetra­decane bis(3‐carboxy‐5‐nitro­benz­oate), C₁₆H₃₈N₄²⁺·2C₈H₄NO₆^?, is a salt in which the cation is present as two configurational isomers, disordered across a common centre of inversion in P, with occupancies of 0.847 (3) and 0.153 (3). The anions are linked into chains by a single O—H?O hydrogen bond [H?O 1.71 Å, O?O 2.5063 (15) Å and O—H?O 156°] and the cations link these anion chains into sheets by means of a range of N—H?O hydrogen bonds [H?O 1.81–2.53 Å, N?O 2.718 (5)–3.3554 (19) Å and N—H?O 146–171°].     

2‐Amino‐5‐chloro‐1,3‐benzoxazol‐3‐ium 2‐(3,4‐di­chloro­phenoxy)­acetate

The 1:1 organic salt of the title compound, C₇H₆ClN₂O⁺·C₈H₅Cl₂O₃^? or [(2‐ABOX)(3,4‐D)], comprises the two constituent mol­ecules associated by an R₂²(8) graph‐set interaction through the carboxyl­ate group of 3,4‐D across the protonated N/N sites of 2‐ABOX [N?O 2.546 (3) and 2.795 (3) Å]. Cation/anion pairs associate across an inversion centre forming discrete tetramers via an additional three‐centre hydrogen‐bonding association from the latter N amino proton to a phenoxy O atom [N?O 3.176 (3) Å] and a carboxyl­ate O atom [N?O 2.841 (3) Å]. This formation differs from the polymeric hydrogen‐bonded chains previously observed for adduct structures of 2‐ABOX with carboxyl­ic acids.     

catena‐Poly[[(trifluoro­methane­sulfon­ato‐κO)silver(I)]‐μ‐di‐2‐pyridyl­amine‐κ2N2:N2′], a chain polymer with short Ag⋯C contacts

The title compound, [Ag(CF₃O₃S)(C₁₀H₉N₃)]_n, is a chain polymer in which neighbouring monomeric units are related by a glide plane. The silver centre is four‐coordinate; the donor atoms are one trifluoro­methane­sulfonate O atom and one pyridine N atom from each of two symmetry‐related dipyridylamines, and an additional and unexpected Ag⋯C contact [2.6464 (16) Å] is observed to a pyridine C atom. The chains are reinforced by one classical N—H⋯O and two `weak' C—H⋯O hydrogen bonds.     

Hydro­gen‐bond networks in tris(4‐hydroxy­phenyl)­methane and its 1:1 molecular complex with 4,4′‐bi­pyridine

In tris(4‐hydroxy­phenyl)­methane (or 4,4′,4′′‐methane­triyl­tri­phenol), C₁₉H₁₆O₃, mol­ecules are connected by O—H⃛O hydrogen bonds [O⃛O = 2.662 (2) and 2.648 (2) Å] into two‐dimensional square networks that are twofold interpenetrated. In tris(4‐hydroxy­phenyl)­methane–4,4′‐bi­pyridine (1/1), C₁₉H₁₆O₃·C₁₀H₈N₂, trisphenol mol­ecules form rectangular networks via O—H⃛O [O⃛O = 2.694 (3) Å] and C—H⃛O [C⃛O = 3.384 (3) Å] hydrogen bonds. Bi­pyridine mol­ecules hydrogen bonded to phenol moieties [O⃛N = 2.622 (3) and 2.764 (3) Å] fill the voids to complete the structure.     

Bis­(di­cyclo­hexyl­ammonium) adipate monohydrate

In the asymmetric unit of the title compound, 2C₁₂H₂₄N⁺·C₆H₈O₄^2?·H₂O, the carboxyl­ate ion lies about an inversion center, the water mol­ecule is on a twofold axis and the sec‐ammonium cation is in a general position. Cations link the oxy­gen ends of two adjacent carboxyl­ate anions to form an eight‐membered ring [N?O 2.683 (3) and 2.711 (3) Å]. The ion pair propagates as a linear chain and adjacent chains are linked through the water mol­ecules [O?O 2.966 (3) Å] into layers.     

Layered structures in proton‐transfer compounds of 5‐sulfosalicylic acid with the aromatic polyamines 2,6‐diamino­pyridine and 1,4‐phenyl­ene­diamine

The crystal structures of two proton‐transfer compounds of 3‐carb­oxy‐4‐hydroxy­benzene­sulfonic acid (5‐sulfosalicylic acid) with the aromatic polyamines 2,6‐diamino­pyridine [namely 2,6‐diamino­pyridinium 3‐carb­oxy‐4‐hydroxy­benzene­sulfonate monohydrate, C₅H₈N₃⁺·C₇H₅O₆S⁻·H₂O, (I)] and 1,4‐phenyl­ene­diamine [namely 1,4‐phenyl­ene­diaminium 3‐carboxyl­ato‐4‐hydroxy­benzene­sulfonate, C₆H₁₀N₂²⁺·C₇H₄O₆S²⁻, (II)] have been determined. Both compounds feature extensively hydrogen‐bonded three‐dimensional layered polymer structures having significant inter­layer π–π inter­actions between the cation and anion species. In (I), the pyridine N atom of the Lewis base is protonated and forms a direct hydrogen‐bonding inter­action with the water mol­ecule, which together with the two amine groups of the cation and the carboxylic acid group of the anion also give additional inter­actions with O‐atom acceptors of the sulfonate group. In (II), a dianionic species results from deprotonation of both the sulfonic and the carboxylic acid groups, and all available O‐atom acceptors inter­act with all dication donors, which lie about inversion centres.     

Adducts of 1,1,1‐tris(4‐hydroxyphenyl)ethane with diamines: three‐dimensional hydrogen‐bonded frameworks formed with 1,6‐diaminohexane and 2,2′‐bipyridyl

The adduct 1,6‐di­amino­hexane–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2) is a salt {hexane‐1,6‐diyldiammonium–4‐[1,1‐bis(4‐hydroxyphenyl)ethyl]phenolate (1/2)}, C₆H₁₈N₂²⁺·2C₂₀H₁₇O₃^?, in which the cation lies across a centre of inversion in space group P. The anions are linked by two short O—H?O hydrogen bonds [H?O 1.74 and 1.76 Å, O?O 2.5702 (12) and 2.5855 (12) Å, and O—H?O 168 and 169°] into a chain containing two types of R(24) ring. Each cation is linked to four different anion chains by three N—H?O hydrogen bonds [H?O 1.76–2.06 Å, N?O 2.6749 (14)–2.9159 (14) Å and N—H?O 156–172°]. In the adduct 2,2′‐bipyridyl–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2), C₁₀H₈N₂·2C₂₀H₁₈O₃, the neutral di­amine lies across a centre of inversion in space group P2₁/n. The tris­(phenol) mol­ecules are linked by two O—H?O hydrogen bonds [H?O both 1.90 Å, O?O 2.7303 (14) and 2.7415 (15) Å, and O—H?O 173 and 176°] into sheets built from R(38) rings. Pairs of tris­(phenol) sheets are linked via the di­amine by means of a single O—H?N hydrogen bond [H?N 1.97 Å, O?N 2.7833 (16) Å and O—H?N 163°].     

The calcium‐binding properties of pamidronate,a bone‐resorption inhibitor

The title compound, calcium bis(3‐ammonio‐1‐hydroxy­propyl­idene‐1,1‐bis­phospho­nate) dihydrate, Ca²⁺·2C₃H₁₀N­O₇P₂^?·2H₂O, consists of calcium octahedra arranged in columns along the c axis and coordinated by hydrogen‐bonded molecular anions. The Ca²⁺ cation lies on a twofold axis. Pamidronate adopts a twisted conformation of the hydroxy­alkyl­amine backbone that enables the formation of an intramolecular N—H?O hydrogen bond. The molecular anion is chelating monodentate as well as bidentate, with an O?O bite distance of 3.0647 (15) Å.     

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.     

4,5‐Di­hydro‐3‐methyl‐5‐(4‐methyl­phenyl)‐1H‐pyrazole‐1‐carboxamidinium acetate acetone hemisolvate

The X‐ray structure analysis of the unexpected product of the reaction between 4‐(4‐methyl­phenyl)­but‐3‐en‐2‐one and amino­guanidine revealed the title compound, C₁₂H₁₇N₄⁺·C₂H₃O₂^?·0.5C₃H₆O, consisting of a protonated amidine moiety joined to a substituted pyrazoline ring at the N1 atom. The amidine group is protonated and the positive charge is delocalized over the three C—N bonds in a similar manner to that found in guanidinium salts. The amidinium moiety of the cation is linked to the acetate anions through four N—H?O hydrogen bonds, with N?O distances of 2.749 (4), 2.848 (4), 2.904 (4) and 2.911 (4) Å. The pyrazoline ring adopts a flattened envelope conformation and the substituted phenyl ring is oriented perpendicular to the attached heterocycle. The acetone solvate molecule lies across a twofold rotation axis.     

(η6‐Hexamethylbenzene)(mesidine)­ditriflatoruthenium(II)

The crystal structure of the title complex, (η⁶‐hexamethylbenzene)bis(trifluoromethanesulfonato‐O)(2,4,6‐trimethylanil­ine‐N)ruthenium(II), [Ru(CF₃O₃S)₂(C₁₂H₁₈)(C₉H₁₃N)], is described. The complex has the classic three‐legged piano‐stool structure with a planar arene 1.667 Å from the metal, two monodentate O‐bound tri­fluoro­methane­sulfonate ligands [Ru—O 2.169 (2) and 2.174 (2) Å] and one N‐bound mesidine ligand [Ru—N 2.198 (2) Å]. The Ru—N distance is relatively long and the average Ru—O distance is relatively short when compared with previously characterized Ru^II complexes.     

Amino­pyrimidine–carboxyl­(ate) interactions in trimethoprim maleate,an antifolate drug

In the title cocrystal, trimethoprim maleate [2,4‐di­amino‐5‐(3,4,5‐tri­methoxy­benzyl)­pyrimidin‐1‐ium maleate], C₁₄H₁₉­N₄O₃⁺·­C₄H₃O₄^?, the trimethoprim mol­ecule is protonated at N1. The carboxyl group of the maleate ion makes a specific double hydrogen bond of type N—H?O with the 2‐amino group and the protonated N1 atom of the trimethoprim cation which is similar to the carboxyl­ate–trimethoprim cation interaction observed in the complex of di­hydro­folate reductase with trimethoprim. The pyrimidine moieties of trimethoprim cations are centrosymmetrically paired through a pair of N—H?N hydrogen bonds involving the 4‐amino group and the pyridinium N3 atom of a symmetry‐related molecule. One of the O atoms at the maleate carboxyl­ate group bridges the 2‐­amino and 4‐amino groups on either side of the paired trimethoprim cations. The other O atom of the carboxyl­ate group forms an intramolecular O—H?O hydrogen bond with the carboxyl group. These characteristic hydrogen bonds result in infinite two‐dimensional aggregation of rings into a supramolecular ladder, which is further crosslinked through weak C—H?O interactions with methoxy groups of neighbouring trimethoprim mol­ecules to form a layered structure.     

(8‐Dimethylamino‐1‐naphthyl)dimethylammonium 3‐carboxy‐1,4,5,‐6,7,7‐hexachlorobicyclo[2.2.1]hept‐5‐ene‐2‐carboxylate hydrate

The structure of the title compound, C₁₄H₁₉N₂⁺·C₉H₃Cl₆O₄^?·H₂O, consists of singly ionized 1,4,5,6,7,7‐hexachlorobicyclo[2.2.1]hept‐5‐ene‐2,3‐dicarboxylic acid anions and protonated 1,8‐bis(dimethylamino)naphthalene cations. In the (8‐dimethylamino‐1‐napthyl)dimethylammonium cat­ion, a strong disordered intramolecular hydrogen bond is formed with N?N = 2.589 (3) Å. The geometry and occupancy obtained in the final restrained refinement suggest that the disordered hydrogen bond may be asymmetric. Water mol­ecules link the anion dimers into infinite chains via hydrogen bonding.     

μ‐Oxo‐bis{[(6‐hydroxy­methyl‐2‐pyridyl­methyl)­bis(2‐pyridyl­methyl)­amine‐κ5N,N′,N′′,N′′′,O]­iron(III)} tetrakis­(perchlorate)

The novel μ‐oxo‐diiron complex [Fe₂O(BPHPA)₂](ClO₄)₄ [BPHPA is (6‐hydroxy­methyl‐2‐pyridyl­methyl)­bis(2‐pyridyl­methyl)­amine, C₁₉H₂₀N₄O], contains a binuclear centrosymmetric [Fe₂O(BPHPA)₂]⁴⁺ cation (the bridging O atom lies on an inversion centre) and four perchlorate anions. Each iron ion is coordinated by four N atoms [Fe—N = 2.117 (5)–2.196 (5) Å] and one O atom [Fe—O = 2.052 (5) Å] from a BPHPA ligand, and by one bridging oxo atom [Fe—O = 1.7896 (9) Å], forming a distorted octahedron. There are hydrogen bonds between the hydroxy group and perchlorate O atoms [O—H·O = 2.654 (7) Å].     

The effects of substitution on tetrakis­(substituted imidazole)­copper(II) tri­fluoro­methane­sulfonates

The organic ligands 4‐methyl‐1H‐imidazole and 2‐ethyl‐4‐methyl‐1H‐imidazole react with Cu(CF₃SO₃)₂·6H₂O to give tetrakis(5‐methyl‐1H‐imidazole‐κN³)­cop­per(II) bis­(tri­fluoro­methane­sulfonate), [Cu(C₄H₆N₂)₄](CF₃SO₃)₂, and aqua­tetrakis(2‐ethyl‐5‐methyl‐1H‐imidazole‐κN³)copper(II) bis(tri­ fluoro­methane­sulfonate), [Cu(C₆H₁₀N₂)₄(H₂O)](CF₃SO₃)₂. In the former, the Cu atom has an elongated octahedral coordination environment, with four imidazole rings in equatorial positions and two tri­fluoro­methane­sulfonate ions in axial positions. This conformation is similar to those in the analogous complexes tetrakis­(imidazole)­cop­per(II) tri­fluoro­methane­sulfonate and tetrakis(2‐methyl‐1H‐imidazole)­cop­per(II) tri­fluoro­methane­sulfonate. In the second of the title compounds, the ethyl groups block the central Cu atom, and a square‐pyramidal coordination environment is formed around the Cu atom, with the substituted imidazole rings in the basal positions and a water mol­ecule in the axial position.     

Betainium tri­fluoro­acetate

The title compound, C₅H₁₂NO₂⁺·C₂F₃O₂^? or BET⁺·CF₃COO^? [BET is tri­methyl­glycine (betaine); IUPAC: 1‐carboxy‐N,N,N‐tri­methyl­methanaminium inner salt], contains pairs of bet­ainium and tri­fluoro­acetate ions forming a dimer bridged by a strong hydrogen bond between the carboxyl and carboxyl­ate groups of the two ions. The molecular symmetry of the cation is close to C_s, with protonation occurring at the carboxy O atom positioned anti to the N atom. The tri­fluoro­acetate anions are disordered over two positions. In one, the conformation of the CF₃ group is staggered with respect to the carboxyl­ate group, in the other, it is close to an eclipsed conformation. The sole hydrogen bond present in the structure is the strong O—H?O bond between the anion and the cation.