Cadmium(II) thio‐ and selenocyanate complexes of 3,3′‐bis(1,2,4‐triazol‐4‐yl)‐1,1′‐biadamantane,a ligand designed with an `extended nanodiamond' aliphatic platform

In the structures of the Cd^II pseudohalide coordination polymer poly[[diaquabis[μ₂‐3,3′‐bis(1,2,4‐triazol‐4‐yl)‐1,1′‐biadamantane‐κ²N¹:N^1′]cadmium(II)] dithiocyanate dihydrate], {[Cd(C₂₄H₃₂N₆)₂(H₂O)₂](NCS)₂·2H₂O}_n, (I), and the isomorphous selenocyanate analogue, {[Cd(C₂₄H₃₂N₆)₂(H₂O)₂](NCSe)₂·2H₂O}_n, (II), the Cd^II cations occupy inversion centres and have octahedral CdN₄O₂ environments, completed by four N atoms of the organic ligands [Cd—N = 2.316 (2) and 2.361 (2) Å for (I), and 2.313 (3) and 2.372 (3) Å for (II)] and two trans‐coordinated aqua ligands [Cd—O = 2.3189 (15) Å for (I) and 2.323 (2) Å for (II)]. In each compound, the ligand displays a bidentate N¹:N^1′‐bridging mode, connecting the metal centres at a distance of 14.66 Å into two‐dimensional nets of (4,4)‐topology, while the uncoordinated thio(seleno)cyanate anions reside inside the net cavities. Hydrogen bonding between the water molecules, anions and 1,2,4‐triazole N atoms supports the tight packing, with an interlayer distance of 6.09 Å.     

Cadmium(II) iodide and thiocyanate complexes adopted by polycyclic 1,4‐bis(pyridazin‐4‐yl)benzene: interplay of coordination and π–π stacking interactions

New complexes containing the 1,4‐bis(pyridazin‐4‐yl)benzene ligand, namely diaquatetrakis[1,4‐bis(pyridazin‐4‐yl)benzene‐κN²]cadmium(II) hexaiodidodicadmate(II), [Cd(C₁₄H₁₀N₄)₄(H₂O)₂][Cd₂I₆], (I), and poly[[μ‐1,4‐bis(pyridazin‐4‐yl)benzene‐κ²N²:N^2′]bis(μ‐thiocyanato‐κ²N:S)cadmium(II)], [Cd(NCS)₂(C₁₄H₁₀N₄)]_n, (II), demonstrate the adaptability of the coordination geometries towards the demands of slipped π–π stacking interactions between the extended organic ligands. In (I), the discrete cationic [Cd—N = 2.408 (3) and 2.413 (3) Å] and anionic [Cd—I = 2.709 (2)–3.1201 (14) Å] entities are situated across centres of inversion. The cations associate via complementary O—H...N^2′ hydrogen bonding [O...N = 2.748 (4) and 2.765 (4) Å] and extensive triple π–π stacking interactions between pairs of pyridazine and phenylene rings [centroid–centroid distances (CCD) = 3.782 (4)–4.286 (3) Å] to yield two‐dimensional square nets. The [Cd₂I₆]²⁻ anions reside in channels generated by packing of successive nets. In (II), the Cd^II cation lies on a centre of inversion and the ligand is situated across a centre of inversion. A two‐dimensional coordination array is formed by crosslinking of linear [Cd(μ‐NCS)₂]_n chains [Cd—N = 2.3004 (14) Å and Cd—S = 2.7804 (5) Å] with N²:N^2′‐bidentate organic bridges [Cd—N = 2.3893 (12) Å], which generate π–π stacks by double‐slipped interactions between phenylene and pyridazine rings [CCD = 3.721 (2) Å].     

(E)‐N′‐(4‐Chlorobenzylidene)‐, (E)‐N′‐(4‐bromobenzylidene)‐ and (E)‐N′‐[4‐(diethylamino)benzylidene]‐ derivatives of 4‐hydroxybenzohydrazide

The 4‐chloro‐ [C₁₄H₁₁ClN₂O₂, (I)], 4‐bromo‐ [C₁₄H₁₀BrN₂O₂, (II)] and 4‐diethylamino‐ [C₁₈H₂₁N₃O₂, (III)] derivatives of benzylidene‐4‐hydroxybenzohydrazide, all crystallize in the same space group (P2₁/c), (I) and (II) also being isomorphous. In all three compounds, the conformation about the C=N bond is E. The molecules of (I) and (II) are relatively planar, with dihedral angles between the two benzene rings of 5.75 (12) and 9.81 (17)°, respectively. In (III), however, the same angle is 77.27 (9)°. In the crystal structures of (I) and (II), two‐dimensional slab‐like networks extending in the a and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐tail viaπ–π interactions involving the aromatic rings [centroid–centroid distance = 3.7622 (14) Å in (I) and 3.8021 (19) Å in (II)]. In (III), undulating two‐dimensional networks extending in the b and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐head viaπ–π interactions involving inversion‐related benzene rings [centroid–centroid distances = 3.6977 (12) and 3.8368 (11) Å].     

New organic–inorganic frameworks incorporating iso‐ and heteropolymolybdate units and a 3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium multiple hydrogen‐bond donor

Poly[bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) γ‐octamolybdate(VI) dihydrate], {(C₁₀H₁₆N₄)₂[Mo₈O₂₆]·2H₂O}_n, (I), and bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) α‐dodecamolybdo(VI)silicate tetrahydrate, (C₁₀H₁₆N₄)₂[SiMo₁₂O₄₀]·4H₂O, (II), display intense hydrogen bonding between the cationic pyrazolium species and the metal oxide anions. In (I), the asymmetric unit contains half a centrosymmetric γ‐type [Mo₈O₂₆]⁴⁻ anion, which produces a one‐dimensional polymeric chain by corner‐sharing, one cation and one water molecule. Three‐centre bonding with 3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium, denoted [H₂Me₄bpz]²⁺ [N...O = 2.770 (4)–3.146 (4) Å], generates two‐dimensional layers that are further linked by hydrogen bonds involving water molecules [O...O = 2.902 (4) and 3.010 (4) Å]. In (II), each of the four independent [H₂Me₄bpz]²⁺ cations lies across a twofold axis. They link layers of [SiMo₁₂O₄₀]⁴⁻ anions into a three‐dimensional framework, and the preferred sites for pyrazolium/anion hydrogen bonding are the terminal oxide atoms [N...O = 2.866 (6)–2.999 (6) Å], while anion/aqua interactions occur preferentially viaμ₂‐O sites [O...O = 2.910 (6)–3.151 (6) Å].     

An X‐ray crystallographic and density functional theory study of (3Z)‐4‐(5‐ethylsulfonyl‐2‐hydroxyanilino)pent‐3‐en‐2‐one and (3Z)‐4‐(5‐tert‐butyl‐2‐hydroxyanilino)pent‐3‐en‐2‐one

The Schiff base enaminones (3Z)‐4‐(5‐ethylsulfonyl‐2‐hydroxyanilino)pent‐3‐en‐2‐one, C₁₃H₁₇NO₄S, (I), and (3Z)‐4‐(5‐tert‐butyl‐2‐hydroxyanilino)pent‐3‐en‐2‐one, C₁₅H₂₁NO₂, (II), were studied by X‐ray crystallography and density functional theory (DFT). Although the keto tautomer of these compounds is dominant, the O=C—C=C—N bond lengths are consistent with some electron delocalization and partial enol character. Both (I) and (II) are nonplanar, with the amino–phenol group canted relative to the rest of the molecule; the twist about the N(enamine)—C(aryl) bond leads to dihedral angles of 40.5 (2) and −116.7 (1)° for (I) and (II), respectively. Compound (I) has a bifurcated intramolecular hydrogen bond between the N—H group and the flanking carbonyl and hydroxy O atoms, as well as an intermolecular hydrogen bond, leading to an infinite one‐dimensional hydrogen‐bonded chain. Compound (II) has one intramolecular hydrogen bond and one intermolecular C=O...H—O hydrogen bond, and consequently also forms a one‐dimensional hydrogen‐bonded chain. The DFT‐calculated structures [in vacuo, B3LYP/6‐311G(d,p) level] for the keto tautomers compare favourably with the X‐ray crystal structures of (I) and (II), confirming the dominance of the keto tautomer. The simulations indicate that the keto tautomers are 20.55 and 18.86 kJ mol⁻¹ lower in energy than the enol tautomers for (I) and (II), respectively.     

Cobalt(II) and cadmium(II) square grids supported with 4,4′‐bipyrazole and accommodating 3‐carboxyadamantane‐1‐carboxylate

In poly[[bis(μ‐4,4′‐bi‐1H‐pyrazole‐κ²N²:N^2′)bis(3‐carboxyadamantane‐1‐carboxylato‐κO¹)cobalt(II)] dihydrate], {[Co(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (I), the Co²⁺ cation lies on an inversion centre and the 4,4′‐bipyrazole (4,4′‐bpz) ligands are also situated across centres of inversion. In its non‐isomorphous cadmium analogue, {[Cd(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (II), the Cd²⁺ cation lies on a twofold axis. In both compounds, the metal cations adopt an octahedral coordination, with four pyrazole N atoms in the equatorial plane [Co—N = 2.156 (2) and 2.162 (2) Å; Cd—N = 2.298 (2) and 2.321 (2) Å] and two axial carboxylate O atoms [Co—O = 2.1547 (18) Å and Cd—O = 2.347 (2) Å]. In both structures, interligand hydrogen bonding [N...O = 2.682 (3)–2.819 (3) Å] is essential for stabilization of the MN₄O₂ environment with its unusually high (for bulky adamantanecarboxylates) number of coordinated N‐donor co‐ligands. The compounds adopt two‐dimensional coordination connectivities and exist as square‐grid [M(4,4′‐bpz)₂]_n networks accommodating monodentate carboxylate ligands. The interlayer linkage is provided by hydrogen bonds from the carboxylic acid groups via the solvent water molecules [O...O = 2.565 (3) and 2.616 (3) Å] to the carboxylate groups in the next layer [O...O = 2.717 (3)–2.841 (3) Å], thereby extending the structures in the third dimension.     

Three‐dimensional networks in the 1:2 organic salts 2,2′‐biimidazolium bis(3‐carboxy‐4‐hydroxybenzenesulfonate) and 2,2′‐bibenzimidazolium bis(3‐carboxy‐4‐hydroxybenzenesulfonate) trihydrate

The two title compounds of 2,2′‐biimidazole (Bim) with 5‐sulfosalicylic acid (5‐H₂SSA) and 2,2′‐bibenzimidazole (Bbim) with 5‐H₂SSA are 1:2 organic salts, viz. C₆H₈N₄²⁺·2C₇H₅O₆S⁻, (I), and C₁₄H₁₂N₄²⁺·2C₇H₅O₆S⁻·3H₂O, (II). The cation of compound (I) lies on a centre of inversion, whereas that of (II) lies on a twofold axis. Whilst compound (I) is anhydrous, three water molecules are incorporated into the crystal structure of (II). The substitution of imidazole H atoms by other chemical groups may favour the incorporation of water molecules into the crystal structure. In both compounds, the component cations and anions adopt a homogeneous arrangement, forming alternating cation and anion layers which run parallel to the (001) plane in (I) and to the (100) plane in (II). By a combination of N—H...O, O—H...O and C—H...O hydrogen bonds, the ions in both compounds are linked into three‐dimensional networks. In addition, π–π interactions are observed between symmetry‐related benzene rings of Bbim²⁺ cations in (II).     

Two‐dimensional square‐grid frameworks formed by self‐associating copper(II) complexes with 1‐(3‐pyridyl)‐ and 1‐(4‐pyridyl)‐substituted butane‐1,3‐diones

In bis­[1‐(3‐pyridyl)butane‐1,3‐dionato]copper(II) (the Cu atom occupies a centre of inversion), [Cu(C₉H₈NO₂)₂], (I), and bis­[1‐(4‐pyridyl)butane‐1,3‐dionato]copper(II) methanol solvate, [Cu(C₉H₈NO₂)₂]·CH₃OH, (II), the O,O′‐chelating diketonate ligands support square‐planar coordination of the metal ions [Cu—O = 1.948 (1)–1.965 (1) Å]. Weaker Cu⋯N inter­actions [2.405 (2)–2.499 (2) Å], at both axial sides, occur between symmetry‐related bis­(1‐pyridylbutane‐1,3‐dion­ato)copper(II) mol­ecules. This causes their self‐organization into two‐dimensional square‐grid frameworks, with uniform [6.48 Å for (I)] or alternating [4.72 and 6.66 Å for (II)] inter­layer separations. Guest methanol mol­ecules in (II) reside between the distal layers and form weak hydrogen bonds to coordinated O atoms [O⋯O = 3.018 (4) Å].     

Influence of nitrogen‐containing chelating ligands on the structures of zinc(II) 4,4′‐ethylenedibenzoates

The Zn^II compounds, μ‐4,4′‐ethylenedibenzoato‐bis[acetatoaqua(dipyrido[3,2‐a:2′,3′‐c]phenazine)zinc(II)] dihydrate, [Zn₂(C₂H₃O₂)₂(C₁₆H₁₀O₄)(C₁₈H₁₀N₄)₂(H₂O)₂]·2H₂O, (I), and catena‐poly[[[aqua(pyrazino[2,3‐f][1,10]phenanthroline)zinc(II)]‐μ‐4,4′‐ethylenedibenzoato] N,N‐dimethylformamide hemisolvate], {[Zn(C₁₆H₁₀O₄)(C₁₄H₈N₄)(H₂O)]·0.5C₃H₇NO}_n, (II), display very different structures because of the influence of the N‐donor chelating ligands. In (I), the coordination geometry of each Zn^II centre is distorted octahedral, involving two N atoms from one dipyrido[3,2‐a:2′,3′‐c]phenazine (L1) ligand, and four O atoms from one bis‐chelating acetate anion, one bridging 4,4′‐ethylenedibenzoate (bpea) ligand and one water molecule. Adjacent Zn^II atoms are bridged by one bpea ligand to form a dinuclear complex, and the dinuclear species is centrosymmetric. Two types of π–π interactions between neighbouring dinuclear species have been found: one is between the L1 ligands, and the second is between the L1 and bpea ligands. In this way, an interesting two‐dimensional supramolecular layer is formed. The layers are further linked by O—H...O and O—H...N hydrogen bonds, generating a three‐dimensional supramolecular network. In (II), each Zn^II atom is square‐pyramidally coordinated by two N atoms from one pyrazino[2,3‐f][1,10]phenanthroline ligand, three O atoms from two different bpea ligands and one water molecule. The two bpea dianions are situated across inversion centres. The bpea dianions bridge neighbouring Zn^II centres, giving a one‐dimensional chain structure in the ab plane. As in (I), two types of π–π interactions between neighbouring chains complete a three‐dimensional supramolecular structure. The results indicate that the structures of the N‐donor chelating ligands are the dominant factors determining the final supramolecular structures of the two compounds.     

A novel CdII coordination polymer with 1,1′‐(1,4‐butanediyl)diimidazole

The novel title Cd^II coordination polymer, poly­[[di­chlorocad­mium(II)]‐di‐μ‐1,1′‐(1,4‐butane­diyl)­di­imidazole], [CdCl₂(C₁₀H₁₄N₄)₂]_n, (I), was obtained by reaction of CdCl₂·2.5H₂O and 1,1′‐(1,4‐butane­diyl)diimidazole (hereafter L). In (I), each L molecule coordinates to two Cd^II cations through its two aromatic N atoms, thus acting as a bridging bidentate ligand. The Cd^II cations, which lie on the inversion centre, are bridged by four L molecules to form a two‐dimensional (4,4)‐network. The two‐dimensional square‐grid sheets are superimposed in an offset fashion.     

Three one‐dimensional coordination polymers based on 1,1′‐bis(pyridin‐4‐ylmethyl)‐2,2′‐bi‐1H‐benzimidazole and HgX2 (X = Cl,Br and I)

A new 2,2′‐bi‐1H‐benzimidazole bridging organic ligand, namely 1,1′‐bis(pyridin‐4‐ylmethyl)‐2,2′‐bi‐1H‐benzimidazole, C₂₆H₂₀N₆, L or (I), has been synthesized and used to create three new one‐dimensional coordination polymers, viz.catena‐poly[[dichloridomercury(II)]‐μ‐1,1′‐bis(pyridin‐4‐ylmethyl)‐2,2′‐bi‐1H‐benzimidazole], [HgCl₂(C₂₆H₂₀N₆)]_n, (II), and the bromido, [HgBr₂(C₂₆H₂₀N₆)]_n, (III), and iodido, [HgI₂(C₂₆H₂₀N₆)]_n, (IV), analogues. Free ligand L crystallizes with two symmetry‐independent half‐molecules in the asymmetric unit and each L molecule resides on a crytallographic inversion centre. In structures (II)–(IV), the L ligand is also positioned on a crystallographic inversion centre, whereas the Hg centre resides on a crystallographic twofold axis. Compound (I) adopts an anti conformation in the solid state and forms a two‐dimensional network in the crystallographic bc plane viaπ–π and C—H...π interactions. The three Hg^II coordination complexes, (II)–(IV), have one‐dimensional zigzag chains composed of L and HgX₂ (X = Cl, Br and I), and the Hg^II centres are in a distorted tetrahedral [HgX₂N₂] coordination geometry. Complexes (III) and (IV) are isomorphous, whereas complex (II) displays an interesting conformational difference from the others, i.e. a twist in the flexible bridging ligand.     

Two two‐dimensional MnII and NaI coordination polymers constructed by the flexible benzene‐1,4‐dioxy­acetate ligand

Two new two‐dimensional coordination polymers, poly­[[[aqua(2,2′‐bi­pyridine‐κ²N,N′)manganese(II)]‐μ₃‐p‐phenyl­enebis­(oxy­acet­ato)‐κ³O:O′:O′′] dihydrate], {[Mn(C₁₀H₈O₆)(C₁₀H₈N₂)(H₂O)]·2H₂O}_n, (I), and poly­[[di‐μ‐aqua‐bis­[aqua­sodium(I)]]‐μ₄‐p‐phenyl­enebis­(oxy­acetato)‐κO:O′,O′′:O′′′,O′′′′:O′′′′′], [Na₂(C₁₀H₈O₆)(H₂O)₄]_n, (II), have been synthesized and characterized by X‐ray single‐crystal diffraction. In (I), there are two 1,4‐BDOA²⁻ [p‐phenyl­enebis­(oxy­acetate) or, more commonly, benzene‐1,4‐dioxy­acetate] ligands, each lying about inversion centres, while in (II), there is one such ligand and it also has crystallographically imposed inversion symmetry. In (I), each Mn^II atom displays an octahedral MnN₂O₄ configuration, defined by three carboxyl O atoms of different 1,4‐BDOA²⁻ groups, two N atoms of one 2,2′‐bi­pyridine ligand and one water mol­ecule. In (II), each Na^I atom is octahedrally coordinated by one ether O atom, two carboxyl O atoms of different 1,4‐BDOA²⁻ ligands and three water mol­ecules. The metal ions in complexes (I) and (II) are bridged by 1,4‐BDOA²⁻ groups into two‐dimensional layer structures. Furthermore, three‐dimensional supramolecular networks are constructed via hydrogen bonds in (I) and (II), and by additional π–π stacking interactions in (I).     

Synthesis and crystal structure of heteronuclear La( III )‐Cu(II ) complex { [LaCu2(NTA)2(4,4′‐bpy)(H2O)3]NO3·5H2O}n

A novel La( III )‐Cu( II ) heterometallic coordination polymer {[LaCu₂(NTA)₂(4,4′‐bpy)(H₂O)₃]NO₃·5H₂O]_n, where H₃NTA denotes nitrilotriacetic acid and 4,4′‐bpy denotes 4, 4‐bipyridine, was synthesized and characterized by IR spectrum, elemental analysis and X‐ray diffraction. The complex crystallizes in the triclinic space group Pi with cell parameters a = 1.33710(10) nm, b = 1,44530(10) nm, c =1.0949(2) nm, α = 71.905(7)°, β = 74.327(7)°, γ = 64.427(9)°, V = 1.7912(4) nm³and Z = 2. It consists of heterometallic units, in which each La( II ) ion is coordinated in a distorted monocapped square antiprism by three oxygen atoms from water molecules and six carboxyl oxygen atoms from five NTA^3? ions, and each Cu( I ) ion is coordinated by one nitrogen atom from 4,4′‐bpy and one nitrogen atom, three oxygen atoms from NTA^3?. In the title complex, La( I ) ions and Cu( II ) ions are connected by the heterometallic bridging of NTA^3?, constructing a two‐dimensional network structure along the [110]. And it is extended into an infinite three‐dimensional network structure by the formation of homometallic bridging of Cu‐4, 4′‐bpy‐Cu, exhibiting a certain inclusion ability.     

One‐dimensional CuII coordination polymers containing C2h‐symmetric 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate linkers

Two new one‐dimensional Cu^II coordination polymers (CPs) containing the C_2h‐symmetric terphenyl‐based dicarboxylate linker 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate (3,3′‐TPDC), namely catena‐poly[[bis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ⁴O,O′:O′′:O′′′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂]·H₂O}_n, (I), and catena‐poly[[aquabis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ²O³:O^3′] monohydrate], {[Cu(C₂₀H₁₂O₄)(C₂H₇N)₂(H₂O)]·H₂O}_n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X‐ray crystallography. The 3,3′‐TPDC bridging ligands coordinate the Cu^II ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one‐dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one‐dimensional coordination polymer chains, forming a two‐dimensional network in (I) and a three‐dimensional network in (II).     

A novel copper(II) coordination polymer with 2,2′‐bipyridyl‐3,3′‐di­carboxylic acid

A novel copper(II) coordination polymer, poly­[[[aqua­copper(II)]‐μ₃‐2,2′‐bipyridyl‐3,3′‐di­carboxyl­ato‐κ⁴N,N′:O:O′] dihydrate], {[Cu(C₁₂H₆N₂O₄)(H₂O)]·2H₂O}_n, was obtained by the reaction of CuCl₂·2H₂O and 2,2′‐bipyridyl‐3,3′‐di­carboxylic acid (H₂L) in water. In the mol­ecule, each Cu^II atom is five‐coordinated and lies at the centre of a square‐pyramidal basal plane, bridged by three L ligands to form a two‐dimensional (4,4)‐network. Each L moiety acts as a bridging tetradentate ligand, coordinating to three Cu^II atoms through its two aromatic N atoms and two O atoms of the two carboxyl groups. The two‐dimensional square‐grid sheets superimpose in an off‐set fashion through the inorganic water layer.     

Different nucleobase orientations in two cyclic 2′,3′‐phosphates of purine ribonucleosides: Et3NH(2′,3′‐cAMP) and Et3NH(2′,3′‐cGMP)·H2O

The crystal structures of triethyl­ammonium adenosine cyclic 2′,3′‐phosphate {systematic name: triethyl­ammonium 4‐(6‐amino­purin‐9‐yl)‐6‐hydroxy­methyl‐2‐oxido‐2‐oxoperhydro­furano[3,4‐c][1,3,2]dioxaphosphole}, Et₃NH(2′,3′‐cAMP) or C₆H₁₆N⁺·C₁₀H₁₁N₅O₆P⁻, (I), and guanosine cyclic 2′,3′‐phosphate monohydrate {systematic name: triethyl­ammonium 6‐hydroxy­methyl‐2‐oxido‐2‐oxo‐4‐(6‐oxo‐1,6‐dihydro­purin‐9‐yl)perhydro­furano[3,4‐c][1,3,2]dioxaphosphole monohydrate}, [Et₃NH(2′,3′‐cGMP)]·H₂O or C₆H₁₆N⁺·C₁₀H₁₁N₅O₇P⁻·H₂O, (II), reveal different nucleobase orientations, viz. anti in (I) and syn in (II). These are stabilized by different inter‐ and intra­molecular hydrogen bonds. The structures also exhibit different ribose ring puckering [₄E in (I) and ³T₂ in (II)] and slightly different 1,3,2‐dioxaphospho­lane ring conformations, viz. envelope in (I) and puckered in (II). Infinite ribbons of 2′,3′‐cAMP⁻ and helical chains of 2′,3′‐cGMP⁻ ions, both formed by O—H⋯O, N—H⋯X and C—H⋯X (X = O or N) hydrogen‐bond contacts, characterize (I) and (II), respectively.     

6‐Aza‐2′‐deoxy­uridine and N3‐anisoyl‐6‐aza‐2′‐deoxy­uridine

In 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (6‐aza‐2′‐deoxy­uridine), C₈H₁₁N₃O₅, (I), the conformation of the glycosylic bond is between anti and high‐anti [χ = −94.0 (3)°], whereas the derivative 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐N⁴‐(2‐methoxy­benzoyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (N³‐anisoyl‐6‐aza‐2′‐deoxy­uridine), C₁₆H₁₇N₃O₇, (II), displays a high‐anti conformation [χ = −86.4 (3)°]. The furanosyl moiety in (I) adopts the S‐type sugar pucker (²T₃), with P = 188.1 (2)° and τ_m = 40.3 (2)°, while the sugar pucker in (II) is N (³T₄), with P = 36.1 (3)° and τ_m = 33.5 (2)°. The crystal structures of (I) and (II) are stabilized by inter­molecular N—H⋯O and O—H⋯O inter­actions.     

Three‐dimensional networks in 5‐methylimidazolium 3‐carboxy‐4‐hydroxybenzenesulfonate and bis(5‐methylimidazolium) 3‐carboxylato‐4‐hydroxybenzenesulfonate

The two title proton‐transfer compounds, 5‐methylimidazolium 3‐carboxy‐4‐hydroxybenzenesulfonate, C₄H₇N₂⁺·C₇H₅O₆S⁻, (I), and bis(5‐methylimidazolium) 3‐carboxylato‐4‐hydroxybenzenesulfonate, 2C₄H₇N₂⁺·C₇H₅O₆S²⁻, (II), are each organized into a three‐dimensional network by a combination of X—H...O (X = O, N or C) hydrogen bonds, and π–π and C—H...π interactions.     

A new three‐dimensional cobalt(II) coordination polymer with a 4‐connected CdSO4‐like topology

The title cobalt(II) coordination polymer, poly[[diaquacobalt(II)]‐μ₄‐3,3′‐(p‐phenylene)diacrylato], [Co(C₁₂H₈O₄)(H₂O)₂]_n, was obtained by reaction of Co(NO₃)₂·6H₂O and 3,3′‐(p‐phenylene)diacrylic acid (H₂L) under hydrothermal conditions. Each Co^II cation sits on a centre of inversion and is hexacoordinated by six O‐atom donors in an octahedral geometry. The Co^II centres are connected by four centrosymmetric L²⁻ anions, resulting in a three‐dimensional framework structure. The coordinated water molecules and carboxylate O atoms form hydrogen‐bond interactions, stabilizing the structure of the three‐dimensional framework. Topologically, the framework represents a rare example of the three‐dimensional 4‐connected CdSO₄ network type. The metal cations and the organic ligand both show in‐plane coordination with respect to the extended structure.     

A three‐dimensional cadmium(II) coordination polymer: poly[[[μ‐4,4′‐(propane‐1,3‐diyl)dipyridine‐κ2N:N](μ‐3,3′‐thiodipropionato‐κ3O,O′:O)cadmium(II)] monohydrate]

In the title coordination polymer, {[Cd(C₆H₈O₄S)(C₁₃H₁₄N₂)]·H₂O}_n, the Cd^II atom displays a distorted octahedral coordination, formed by three carboxylate O atoms and one S atom from three different 3,3′‐thiodipropionate ligands, and two N atoms from two different 4,4′‐(propane‐1,3‐diyl)dipyridine ligands. The Cd^II centres are bridged through carboxylate O atoms of 3,3′‐thiodipropionate ligands and through N atoms of 4,4′‐(propane‐1,3‐diyl)dipyridine ligands to form two different one‐dimensional chains, which intersect to form a two‐dimensional layer. These two‐dimensional layers are linked by S atoms of 3,3′‐thiodipropionate ligands from adjacent layers to form a three‐dimensional network.