catena‐Poly[[bis(acetonitrile‐κN)manganese(II)]‐bis(μ‐trifluoromethanesulfonato‐κ2O:O′)]

The title compound, [Mn(CF₃SO₃)₂(CH₃CN)₂]_n, has an Mn^II cation on an inversion centre in an octahedral environment. The trifluoromethanesulfonate anions act as bridging ligands and form a one‐dimensional coordination polymer in the direction of the a axis. The F atoms of the trifluoromethanesulfonate anions form layers parallel to the ab plane, but despite short intermolecular distances, no stabilizing F...F interactions are detected. The Mn—N and C—C bonds of the acetonitrile ligand are analyzed according to the Hirshfeld rigid‐bond test. Renninger effects in the reflection data are considered, explored and discussed.     

Di‐μ‐hydroxido‐bis{[bis(6‐methyl‐2‐pyridylmethyl)(2‐phenylethyl)amine‐κ3N′,N′′,N′′′]copper(II)} bis(perchlorate)

The title compund, [Cu₂(OH)₂(C₂₂H₂₅N₃)₂](ClO₄)₂, is a copper(II) dimer, with two [CuL]²⁺ units [L is bis(6‐methyl‐2‐pyridylmethyl)(2‐phenylethyl)amine] bridged by hydroxide groups to define the {[CuL](μ‐OH)₂[CuL]}²⁺ cation. Charge balance is provided by perchlorate counter‐anions. The cation has a crystallographic inversion centre halfway between the Cu^II ions, which are separated by 3.0161 (8) Å. The central core of the cation is an almost regular Cu₂O₂ parallelogram of sides 1.931 (2) and 1.935 (2) Å, with a Cu—O—Cu angle of 102.55 (11)°. The coordination geometry around each Cu^II centre can be best described as a square‐based pyramid, with three N atoms from L ligands and two hydroxide O atoms completing the coordination environment. Each cationic unit is hydrogen bonded to two perchlorate anions by means of hydroxide–perchlorate O—H...O interactions.     

X‐ray and DFT‐calculated structures of bis[N‐(quinolin‐8‐yl)benzamidato‐κ2N,N′]copper(II)

The application of transition metal chelates as chemotherapeutic agents has the advantage that they can be used as a scaffold around which ligands with DNA recognition elements can be anchored. The facile substitution of these components allows for the DNA recognition and binding properties of the metal chelates to be tuned. Copper is a particularly interesting choice for the development of novel metallodrugs as it is an endogenous metal and is therefore less toxic than other transition metals. The title compound, [Cu(C₁₆H₁₁N₂O)₂], was synthesized by reacting N‐(quinolin‐8‐yl)benzamide and the metal in a 2:1 ratio. Ligand coordination required deprotonation of the amide N—H group and the isolated complex is therefore neutral. The metal ion adopts a flattened tetrahedral coordination geometry with the ligands in a pseudo‐trans configuration. The free rotation afforded by the formal single bond between the amide group and phenyl ring allows the phenyl rings to rotate out‐of‐plane, thus alleviating nonbonded repulsion between the phenyl rings and the quinolyl groups within the complex. Weak C—H…O interactions stabilize a dimer in the solid state. Density functional theory (DFT) simulations at the PBE/6‐311G(dp) level of theory show that the solid‐state structure (C1 symmetry) is 79.33 kJ mol⁻¹ higher in energy than the lowest energy gas‐phase structure (C2 symmetry). Natural bond orbital (NBO) analysis offers an explanation for the formation of the C—H…O interactions in electrostatic terms, but the stabilizing effect is insufficient to support the dimer in the gas phase.     

Bis(2‐amino‐1H‐benzimidazol‐3‐ium) tetrakis(μ‐but‐2‐enoato)‐κ4O:O′;κ3O,O′:O;κ3O:O,O′‐bis[bis(but‐2‐enoato‐κ2O,O′)holmium(III)]

The title ionic compound, (C₇H₈N₃)₂[Ho₂(C₄H₅O₂)₈], is constructed from two almost identical independent centrosymmetric anionic dimers balanced by two independent 2‐amino‐1H‐benzimidazol‐3‐ium (Habim⁺) cations. The asymmetric part of each dimer is made up of one Ho^III cation and four crotonate (crot or but‐2‐enoate) anions, two of them acting in a simple η²‐chelating mode and the remaining two acting in two different μ₂:η² fashions, viz. purely bridging and bridging–chelating. Symmetry‐related Ho^III cations are linked by two Ho—O—Ho and two Ho—O—C—O—Ho bridges which lead to rather short intracationic Ho...Ho distances [3.8418 (3) and 3.8246 (3) Å]. In addition to the obvious Coulombic interactions linking the cations and anions, the isolated [Ho₂(crot)₈]²⁻ and Habim⁺ ions are linked by a number of N—H...O hydrogen bonds, in which all N—H groups of the cation are involved as donors and all (simple chelating) crot O atoms are involved as acceptors. These interactions result in compact two‐dimensional structures parallel to (110), which are linked to each other by weaker π–π contacts between Habim⁺ benzene groups.     

Bis(2,6‐diamino‐1H‐purin‐3‐ium) di‐μ‐croconato‐κ3O,O′:O′′;κ3O:O′,O′′‐bis[tetraaqua(croconato‐κ2O,O′)neodymium(III)]

The structure of the ionic title compound, (C₅H₇N₆)₂[Nd₂(C₅O₅)₄(H₂O)₈], consists of anionic dimers built around an inversion centre and is made up of an Nd^III cation, two croconate (croco) dianions and four water molecules (plus their inversion images), with two noncoordinated symmetry‐related 2,6‐diamino‐1H‐purin‐3‐ium (Hdap⁺) cations providing charge balance. Each Nd^III atom is bound to nine O atoms from four water and three croco units. The coordination polyhedron has the form of a rather regular monocapped square antiprism. The croconate anions are regular and the Hdap⁺ cation presents a unique, thus far unreported, protonation state. The abundance of hydrogen‐bonding donors and acceptors gives rise to a complex packing scheme consisting of dimers interlinked along the three crystallographic directions and defining anionic `cages' where the unbound Hdap⁺ cations lodge, linking to the mainframe via (N—H)_Hdap...O_water/croco and (O—H)_water...N_Hdap interactions.     

The supramolecular architecture in 4,4′‐bipyridinium bis(hydrogen oxalate)

The asymmetric unit of the title compound, C₁₀H₁₀N₂²⁺·2C₂HO₄⁻, consists of one half of a 4,4′‐bipyridinium cation, which has inversion symmetry, and a hydrogen oxalate anion, in which an intramolecular hydrogen bond exists. The cations and anions are connected by O—H...O, N—H...O and C—H...O hydrogen bonds, forming a two‐dimensional network, whereas π–π stacking interactions involving the 4,4′‐bipyridinium cations lead to the formation of a three‐dimensional supramolecular structure. An unusual deca‐atomic ring is formed between two hydrogen oxalate anions, which are linked side‐to‐side via O—H...O hydrogen‐bonding interactions.     

Weak hydrogen and halogen bonding in 4‐[(2,2‐difluoroethoxy)methyl]pyridinium iodide and 4‐[(3‐chloro‐2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium iodide

To enable a comparison between a C—H…X hydrogen bond and a halogen bond, the structures of two fluorous‐substituted pyridinium iodide salts have been determined. 4‐[(2,2‐Difluoroethoxy)methyl]pyridinium iodide, C₈H₁₀F₂NO⁺·I⁻, (1), has a –CH₂OCH₂CF₂H substituent at the para position of the pyridinium ring and 4‐[(3‐chloro‐2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium iodide, C₉H₉ClF₄NO⁺·I⁻, (2), has a –CH₂OCH₂CF₂CF₂Cl substituent at the para position of the pyridinium ring. In salt (1), the iodide anion is involved in one N—H…I and three C—H…I hydrogen bonds, which, together with C—H…F hydrogen bonds, link the cations and anions into a three‐dimensional network. For salt (2), the iodide anion is involved in one N—H…I hydrogen bond, two C—H…I hydrogen bonds and one C—Cl…I halogen bond; additional C—H…F and C—F…F interactions link the cations and anions into a three‐dimensional arrangement.     

2,2′‐Bipyridinium bis(perchlorate)

The title compound, [H₂bipy](ClO₄)₂ or C₁₀H₁₀N₂²⁺·2ClO₄^?, was obtained at the interface between an organic (2,2′‐bi­pyridine in methanol) and an aqueous phase (perchloric acid in water). The compound crystallizes in space group P and comprises discrete diprotonated trans‐bipyridinium cations, [H₂bipy]²⁺, and ClO₄^? anions. The cations and anions are connected through N—H?O and C—H?O hydrogen bonds [distances N?O 2.817 (4) and 2.852 (4) Å, and C?O 3.225 (6)–3.412 (5)Å]. The C—C bond distance between the two rings is 1.452 (5) Å. The bipyridinium cation has a trans conformation and the N—C—C—N torsion angle is 152.0 (3)°.     

A comparative study of two polymorphs of bis(1‐hydroxy‐2‐methylpropan‐2‐aminium) carbonate

Alkanolamines have been known for their high CO₂ absorption for over 60 years and are used widely in the natural gas industry for reversible CO₂ capture. In an attempt to crystallize a salt of (RS)‐2‐(3‐benzoylphenyl)propionic acid with 2‐amino‐2‐methylpropan‐1‐ol, we obtained instead a polymorph (denoted polymorph II) of bis(1‐hydroxy‐2‐methylpropan‐2‐aminium) carbonate, 2C₄H₁₂NO⁺·CO₃²⁻, (I), suggesting that the amine group of the former compound captured CO₂ from the atmosphere forming the aminium carbonate salt. This new polymorph was characterized by single‐crystal X‐ray diffraction analysis at low temperature (100 K). The salt crystallizes in the monoclinic system (space group C2/c, Z = 4), while a previously reported form of the same salt (denoted polymorph I) crystallizes in the triclinic system (space group P, Z = 2) [Barzagli et al. (2012). ChemSusChem, 5 , 1724–1731]. The asymmetric unit of polymorph II contains one 1‐hydroxy‐2‐methylpropan‐2‐aminium cation and half a carbonate anion, located on a twofold axis, while the asymmetric unit of polymorph I contains two cations and one anion. These polymorphs exhibit similar structural features in their three‐dimensional packing. Indeed, similar layers of an alternating cation–anion–cation neutral structure are observed in their molecular arrangements. Within each layer, carbonate anions and 1‐hydroxy‐2‐methylpropan‐2‐aminium cations form planes bound to each other through N—H…O and O—H…O hydrogen bonds. In both polymorphs, the layers are linked to each other via van der Waals interactions and C—H…O contacts. In polymorph II, a highly directional C—H…O contact (C—H…O = 156°) shows as a hydrogen‐bonding interaction. Periodic theoretical density functional theory (DFT) calculations indicate that both polymorphs present very similar stabilities.     

A three‐dimensional framework in 2,2′‐biimidazolium bis(2,2′‐biimidazole‐κ2N,N′)bis(biphenyl‐2,4′‐dicarboxylato‐κO)manganese(II) hexahydrate

In the title salt, (C₆H₈N₄)[Mn(C₁₄H₈O₄)₂(C₆H₆N₄)₂]·6H₂O, the Mn^II atom lies on an inversion centre and is coordinated by four N atoms from two 2,2′‐biimidazole (biim) ligands and two O atoms from two biphenyl‐2,4′‐dicarboxylate (bpdc) anions to give a slightly distorted octahedral coordination, while the cation lies about another inversion centre. Adjacent [Mn(bpdc)₂(biim)₂]²⁻ anions are linked via two pairs of N—H...O hydrogen bonds, leading to an infinite chain along the [100] direction. The protonated [H₂biim]²⁺ moiety acts as a charge‐compensating cation and space‐filling structural subunit. It bridges two [Mn(bpdc)₂(biim)₂]²⁻ anions through two pairs of N—H...O hydrogen bonds, constructing two R₂²(9) rings, leading to a zigzag chain in the [2] direction, which gives rise to a ruffled set of [H₂biim]²⁺[Mn(bpdc)₂(biim)₂]²⁻ moieties in the [01] plane. The water molecules give rise to a chain structure in which O—H...O hydrogen bonds generate a chain of alternating four‐ and six‐membered water–oxygen R₄²(8) and R₆⁶(12) rings, each lying about independent inversion centres giving rise to a chain along the [100] direction. Within the water chain, the (H₂O)₆ water rings are hydrogen bonded to two O atoms from two [Mn(bpdc)₂(biim)₂]²⁻ anions, giving rise to a three‐dimensional framework.     

[μ3‐cis‐N‐(2‐Aminoethyl)‐N′‐(2‐carboxylatophenyl)oxamidato(3−)]bis(2,2′‐diamino‐4,4′‐bi‐1,3‐thiazole)tetracopper(II) bis(2,4,6‐trinitrophenolate)

The title complex, [Cu₄(C₁₁H₁₀N₃O₄)₂(C₆H₆N₄S₂)₂](C₆H₂N₃O₇)₂, consists of a circular tetracopper(II) cation with an embedded inversion centre and two uncoordinated picrate (2,4,6‐trinitrophenolate) anions. The Cu^II cations at the inner sites of N‐(2‐aminoethyl)‐N′‐(2‐carboxylatophenyl)oxamidate(3−) (oxbe) have square‐planar environments and those at the outer sites are in square‐pyramidal geometries. The separations of pairs of Cu^II cations bridged by cis‐oxamide and carboxylate groups are 5.2217 (5) and 5.2871 (5) Å, respectively. The tetracopper(II) cations and picrate anions are connected by N—H...O hydrogen bonds into a two‐dimensional network parallel to the (010) plane, and these two‐dimensional networks are assembled by two types of π–π stacking interactions into a three‐dimensional supramolecular structure.     

Supramolecular interactions in a copper(II) 4′‐(4‐bromophenyl)‐2,2′:6′,2′′‐terpyridine complex

The title compound, [4′‐(4‐bromophenyl)‐2,2′:6′,2′′‐terpyridine]chlorido(trifluoromethanesulfonato)copper(II), [Cu(CF₃O₃S)Cl(C₂₁H₁₄BrN₃)], is a new copper complex containing a polypyridyl‐based ligand. The Cu^II centre is five‐coordinated in a square‐pyramidal manner by one substituted 2,2′:6′,2′′‐terpyridine ligand, one chloride ligand and a coordinated trifluoromethanesulfonate anion. The Cu—N bond lengths differ by 0.1 Å for the peripheral and central pyridine rings [2.032 (2) (mean) and 1.9345 (15) Å, respectively]. The presence of the trifluoromethanesulfonate anion coordinated to the metal centre allows Br...F halogen–halogen interactions, giving rise to the formation of a dimer about an inversion centre. This work also demonstrates that the rigidity of the ligand allows the formation of other types of nonclassical interactions (C—H...Cl and C—H...O), yielding a three‐dimensional network.     

Synthesis,crystal structure and magnetic properties of (acetato‐κ2O,O′)bis(5,5′‐dimethyl‐2,2′‐bipyridine‐κ2N,N′)nickel(II) perchlorate monohydrate

The title hydrated ionic complex, [Ni(CH₃COO)(C₁₂H₁₂N₂)₂]ClO₄·H₂O or [Ni(ac)(5,5′‐dmbpy)₂]ClO₄·H₂O (where 5,5′‐dmbpy is 5,5′‐dimethyl‐2,2′‐bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate–5,5′‐dmbpy–KClO₄ system. Within the complex cation, the Ni^II atom is hexacoordinated by two chelating 5,5′‐dmbpy ligands and one chelating ac ligand. The mean Ni—N and Ni—O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen‐bonded centrosymmetric dimers, which are further connected by π–π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single‐ion anisotropy, D, which arises from the reduced local symmetry of the cis‐NiO₂N₄ chromophore. The fitting of the variable‐temperature magnetic data (2–300 K) gives g_iso = 2.134 and D/hc = 3.13 cm⁻¹.     

Supramolecular hydrogen‐bonding patterns in the organic–inorganic hybrid compound bis(4‐amino‐5‐chloro‐2,6‐dimethylpyrimidinium) tetrathiocyanatozinc(II)–4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–water (1/2/2)

Zinc thiocyanate complexes have been found to be biologically active compounds. Zinc is also an essential element for the normal function of most organisms and is the main constituent in a number of metalloenzyme proteins. Pyrimidine and aminopyrimidine derivatives are biologically very important as they are components of nucleic acids. Thiocyanate ions can bridge metal ions by employing both their N and S atoms for coordination. They can play an important role in assembling different coordination structures and yield an interesting variety of one‐, two‐ and three‐dimensional polymeric metal–thiocyanate supramolecular frameworks. The structure of a new zinc thiocyanate–aminopyrimidine organic–inorganic compound, (C₆H₉ClN₃)₂[Zn(NCS)₄]·2C₆H₈ClN₃·2H₂O, is reported. The asymmetric unit consist of half a tetrathiocyanatozinc(II) dianion, an uncoordinated 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidinium cation, a 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine molecule and a water molecule. The Zn^II atom adopts a distorted tetrahedral coordination geometry and is coordinated by four N atoms from the thiocyanate anions. The Zn^II atom is located on a special position (twofold axis of symmetry). The pyrimidinium cation and the pyrimidine molecule are not coordinated to the Zn^II atom, but are hydrogen bonded to the uncoordinated water molecules and the metal‐coordinated thiocyanate ligands. The pyrimidine molecules and pyrimidinium cations also form base‐pair‐like structures with an R₂²(8) ring motif via N—H…N hydrogen bonds. The crystal structure is further stabilized by intermolecular N—H…O, O—H…S, N—H…S and O—H…N hydrogen bonds, by intramolecular N—H…Cl and C—H…Cl hydrogen bonds, and also by π–π stacking interactions.     

Complexes of nickel(II) and copper(II) with 1,2,4‐triazole‐3‐carboxylic acid and of cobalt(III) with 3‐amino‐1,2,4‐triazole‐5‐carboxylic acid

Because of their versatile coordination modes and strong coordination ability for metals, triazole ligands can provide a wide range of possibilities for the construction of metal–organic frameworks. Three transition‐metal complexes, namely bis(μ‐1,2,4‐triazol‐4‐ide‐3‐carboxylato)‐κ³N ²,O :N ¹;κ³N ¹:N ²,O‐bis[triamminenickel(II)] tetrahydrate, [Ni₂(C₃HN₃O₂)₂(NH₃)₆]·4H₂O, (I), catena‐poly[[[diamminediaquacopper(II)]‐μ‐1,2,4‐triazol‐4‐ide‐3‐carboxylato‐κ³N ¹:N ⁴,O‐[diamminecopper(II)]‐μ‐1,2,4‐triazol‐4‐ide‐3‐carboxylato‐κ³N ⁴,O :N ¹] dihydrate], {[Cu₂(C₃HN₃O₂)₂(NH₃)₄(H₂O)₂]·2H₂O}_n , (II), (μ‐5‐amino‐1,2,4‐triazol‐1‐ide‐3‐carboxylato‐κ²N ¹:N ²)di‐μ‐hydroxido‐κ⁴O :O‐bis[triamminecobalt(III)] nitrate hydroxide trihydrate, [Co₂(C₃H₂N₄O₂)(OH)₂(NH₃)₆](NO₃)(OH)·3H₂O, (III), with different structural forms have been prepared by the reaction of transition metal salts, i.e. NiCl₂, CuCl₂ and Co(NO₃)₂, with 1,2,4‐triazole‐3‐carboxylic acid or 3‐amino‐1,2,4‐triazole‐5‐carboxylic acid hemihydrate in aqueous ammonia at room temperature. Compound (I) is a dinuclear complex. Extensive O—H…O, O—H…N and N—H…O hydrogen bonds and π–π stacking interactions between the centroids of the triazole rings contribute to the formation of the three‐dimensional supramolecular structure. Compound (II) exhibits a one‐dimensional chain structure, with O—H…O hydrogen bonds and weak O—H…N, N—H…O and C—H…O hydrogen bonds linking anions and lattice water molecules into the three‐dimensional supramolecular structure. Compared with compound (I), compound (III) is a structurally different dinuclear complex. Extensive N—H…O, N—H…N, O—H…N and O—H…O hydrogen bonding occurs in the structure, leading to the formation of the three‐dimensional supramolecular structure.     

Side‐chain conformations in the isomorphous polyfluorinated {4,4′‐bis[(2,2‐difluoroethoxy)methyl]‐2,2′‐bipyridine‐κ2N,N′}dichloridopalladium and ‐platinum complexes

The polyfluorinated title compounds, [M Cl₂(C₁₆H₁₆F₄N₂O₂)] or [4,4′‐(HCF₂CH₂OCH₂)₂‐2,2′‐bpy]M Cl₂ [M = Pd, ( 1 ), and M = Pt, ( 2 )], have –C(H_α)₂OC(H_β)₂CF₂H side chains with H‐atom donors at the α and β sites. The structures of ( 1 ) and ( 2 ) are isomorphous, with the nearly planar (bpy)M Cl₂ molecules stacked in columns. Within one column, π‐dimer pairs alternate between a π‐dimer pair reinforced with C—H…Cl hydrogen bonds (α,α) and a π‐dimer pair reinforced with C—H_β…F(—C) interactions (abbreviated as C—H_β…F—C,C—H_β…F—C). The compounds [4,4′‐(CF₃CH₂OCH₂)₂‐2,2′‐bpy]M Cl₂ [M = Pd, ( 3 ), and M = Pt, ( 4 )] have been reported to be isomorphous [Lu et al. (2012). J. Fluorine Chem. 137 , 54–56], yet with disorder in the fluorous regions. The molecules of ( 3 ) [or ( 4 )] also form similar stacks, but with alternating π‐dimer pairs between the (α,β; α,β) and (β,β) forms. Through (C—)H…Cl hydrogen‐bond interactions, one molecule of ( 1 ) [or ( 2 )] is expanded into an aggregate of two inversion‐related π‐dimer pairs, one pair in the (α,α) form and the other pair in the (C—H_β…F—C,C—H_β…F—C) form, with the plane normals making an interplanar angle of 58.24 (3)°. Due to the demands of maintaining a high coordination number around the metal‐bound Cl atoms in molecule ( 1 ) [or ( 2 )], the ponytails of molecule ( 1 ) [or ( 2 )] bend outward; in contrast, the ponytails of molecule ( 3 ) [or ( 4 )] bend inward.     

Two two‐dimensional hydrogen‐bonded coordination networks: bis(3‐carboxybenzoato‐κO)bis(4‐methyl‐1H‐imidazole‐κN3)copper(II) and bis(3‐methylbenzoato‐κN)bis(4‐methyl‐1H‐imidazole‐κN3)copper(II) monohydrate

The title two‐dimensional hydrogen‐bonded coordination compounds, [Cu(C₈H₅O₄)₂(C₄H₆N₂)₂], (I), and [Cu(C₈H₇O₂)₂(C₄H₆N₂)₂]·H₂O, (II), have been synthesized and structurally characterized. The molecule of complex (I) lies across an inversion centre, and the Cu²⁺ ion is coordinated by two N atoms from two 4‐methyl‐1H‐imidazole (4‐MeIM) molecules and two O atoms from two 3‐carboxybenzoate (HBDC⁻) anions in a square‐planar geometry. Adjacent molecules are linked through intermolecular N—H...O and O—H...O hydrogen bonds into a two‐dimensional sheet with (4,4) topology. In the asymmetric part of the unit cell of (II) there are two symmetry‐independent molecules, in which each Cu²⁺ ion is also coordinated by two N atoms from two 4‐MeIM molecules and two O atoms from two 3‐methylbenzoate (3‐MeBC⁻) anions in a square‐planar coordination. Two neutral complex molecules are held together via N—H...O(carboxylate) hydrogen bonds to generate a dimeric pair, which is further linked via discrete water molecules into a two‐dimensional network with the Schläfli symbol (4³)₂(4⁶,6⁶,8³). In both compounds, as well as the strong intermolecular hydrogen bonds, π–π interactions also stabilize the crystal stacking.     

Tetraaquabis[5‐(3‐pyridyl‐κN)pyrimidine]zinc(II) bis(trifluoromethanesulfonate): a novel cationic complex and three‐dimensional hydrogen‐bonded network

The title compound, [Zn(C₉H₇N₃)₂(H₂O)₄](CF₃O₃S)₂, contains an octahedral [ZnL₂(H₂O)₄]²⁺ cationic complex with trans geometry (Zn site symmetry ), and each 5‐(3‐pyridyl)pyrimidine (L) ligand is coordinated in a monodentate fashion through the pyridine N atom. In the extended structure, these complexes, with both hydrogen‐bond acceptor (pyrimidine) and donor (H₂O) functions, are linked to each other by intermolecular water–pyrimidine O—H...N hydrogen‐bonding interactions, resulting in a double chain along the crystallographic a axis. The trifluoromethanesulfonate anions are integrated into the chains via O—H...O hydrogen bonds between the coordinated water and sulfonate O atoms. These double chains are associated into a novel three‐dimensional network through interchain water–pyrimidine O—H...N hydrogen bonds. The asymmetric ligand plays an important role in constructing this unusual supramolecular structure.     

A novel one‐dimensional double‐chain‐like ZnII coordination polymer: poly[bis(1‐benzyl‐1H‐imidazole‐κN3)tris(μ‐cyanido‐κ2C:N)(cyanido‐κC)disilver(I)zinc(II)]

One of most interesting systems of coordination polymers constructed from the first‐row transition metals is the porous Zn^II coordination polymer system, but the numbers of such polymers containing N‐donor linkers are still limited. The title double‐chain‐like Zn^II coordination polymer, [Ag₂Zn(CN)₄(C₁₀H₁₀N₂)₂]_n, presents a one‐dimensional linear coordination polymer structure in which Zn^II ions are linked by bridging anionic dicyanidoargentate(I) units along the crystallographic b axis and each Zn^II ion is additionally coordinated by a terminal dicyanidoargentate(I) unit and two terminal 1‐benzyl‐1H‐imidazole (BZI) ligands, giving a five‐coordinated Zn^II ion. Interestingly, there are strong intermolecular Ag^I…Ag^I interactions between terminal and bridging dicyanidoargentate(I) units and C—H…π interactions between the phenyl rings of BZI ligands of adjacent one‐dimensional linear chains, providing a one‐dimensional linear double‐chain‐like structure. The supramolecular three‐dimensional framework is stabilized by C—H…π interactions between the phenyl rings of BZI ligands and by Ag^I…Ag^I interactions between adjacent double chains. The photoluminescence properties have been studied.     

N,N′‐Bis(2‐ammonioethyl)propane‐1,3‐diaminium tris(perchlorate) chloride

The crystal structure of the title compound, C₇H₂₄N₄⁴⁺·3ClO₄⁻·Cl⁻, is mainly determined by electrostatic interactions between the charged species and a number of relatively weak N—H...O and N—H...Cl⁻ hydrogen bonds. The rich structure of such hydrogen bonds creates infinite layers of ions extending along the [001] direction. The tetracation has the gttttttg conformation, similar to the single previously known example of such a cation. The presence of two different anions can be connected with the undecided competition between them, and some of the packing advantages of such a situation are found in the crystal structure.