NEt4OH·5H2O containing hydro­xide–water layers

In the title compound, tetraethyl­ammonium hydro­xide pentahydrate, C₈H₂₀N⁺·OH^?·5H₂O, layers of approximately hexagonally close‐packed NEt₄⁺ cations and anionic layers of hydro­xide and water mol­ecules are stacked alternately along the b axis. All hydro­xide and water H atoms are in ordered positions, giving rise to a network of hydrogen bonds [O?O 2.633 (1)–2.947 (2) Å] with four‐ and six‐membered rings. The hydro­xide ion accepts four hydrogen bonds from four water mol­ecules but does not act as a proton donor.     

Benzyl­tri­methyl­ammonium hydro­xide trihydrate containing hydro­xide–water layers

In the title compound, C₁₀H₁₆N⁺·OH⁻·3H₂O, two-dimensional bilayer-like arrays of organic cations and corrugated anionic hydro­xide–water layers are stacked alternately along the c axis. All hydro­xide and water H atoms are in ordered positions, giving rise to a network of hydrogen bonds [O⃛O 2.639 (2)–2.927 (2) Å for water donors and O⃛O 3.323 (2) Å for hydro­xide donors] with four- and six-membered rings.     

Tetraaquabis(3,5‐dicarboxybenzoato‐O)cobalt(II)

The hydro­thermal reaction of cobalt(II) chloride with trimesate (3,5‐di­carboxy­benzoate) ions in aqueous solution gives the novel title complex, [Co(C₉H₅O₆)₂(H₂O)₄]. The Co^II ion lies on an inversion centre and is octahedrally coordinated to two trimesate anions and four water mol­ecules. Hydro­gen bonds ensure the three‐dimensional architecture of the structure.     

catena‐Poly­[[di­aqua­(nicotinato‐κ2O,O′)­cadmium(II)]‐μ‐nicotinato‐κ3N:O,O′]

The title compound, [Cd(C₆H₄NO₂)₂(H₂O)₂]_n, forms a one‐dimensional chain structure based on a Cd atom with approximate pentagonal bipyramidal coordination geometry and two nicotinate ligands in different coordination modes. One acts as a tridentate ligand, chelating one Cd atom through the carboxyl­ate group while simultaneously binding to a second symmetry‐related Cd atom through the pyridine N atom; the other acts only as a bidentate ligand through its carboxyl­ate group. Hydro­gen bonds utilizing the coordinated water mol­ecules, uncoordinated nitro­gen and carboxyl­ate O atoms as acceptors link the chains.     

2′,4′‐Di­hydroxy‐3‐methoxy‐α,β‐di­hydro­chalcone and 2′,4‐di­hydroxy‐α,β‐di­hydro­chalcone: supramolecular structures formed by O—H⋯O,C—H⋯O and stacking interactions

The crystal structures of 2′,4′‐di­hydroxy‐3‐methoxy‐α,β‐di­hydro­chalcone, C₁₆H₁₆O₄, and 2′,4‐di­hydroxy‐α,β‐di­hydro­chalcone, C₁₅H₁₄O₃, have been determined. In both compounds, the structure consists of two nearly planar six‐membered aromatic rings connected by a propanal chain, which is bent in the methoxy compound and almost straight in the other compound. In the crystal structures, the molecular units of both compounds are linked by O—H⋯O hydrogen bonds to form infinite one‐dimensional chains. Hydro­gen bonds and C—H⋯O contacts in the crystal structures were studied by topological analysis of charge density based on Hartree–Fock calculations. Almost all of the investigated C—H⋯O contacts should be characterized as weak hydrogen bonds.     

A tetragonal polymorph of caesium hydroxide monohydrate,CsOH·H2O,from X‐ray powder data

Tetragonal caesium hydro­xide monohydrate, CsOH·H₂O, a clathrate hydrate, is a polymorph of three known hexagonal or pseudo‐hexagonal modifications. It was obtained as a by‐product in a high‐pressure experiment. Whether it is a high‐pressure polymorph, however, remains to be verified. The Cs atoms are situated in cavities of the form of a bicapped pentagonal prism, within an infinite three‐dimensional hydrogen‐bonded oxy­gen framework that is locally identical to layers found in the hexagonal modifications. The Cs atom and one of the two H atoms are at sites with symmetry, the O atom has mm site symmetry and the second H atom has 2/m symmetry.     

Benzdiamidine

The mol­ecule of benzene-1,4-dicarbox­amidine or benzdi­amidine, C₈H₁₀N₄, reveals C_i symmetry. Hydro­gen bonds utilize the amino groups as double donors, whereas the imino groups act as double acceptors. The network formed is similar to that observed in the crystal packing of terephthal­amide.     

(N‐Maleoylglycinato)trimethyltin(IV)

The Sn atom in the crystal structure of the title compound,catena‐poly­[trimethyl­tin‐μ‐[(2,5‐di­oxo‐2,5‐di­hydro­pyrrol‐1‐yl)­acetato‐O:O′]], [Sn(CH₃)₃(C₆H₄NO₄)], adopts a distorted trigonal bipyramidal coordination geometry with three methyl groups defining the trigonal plane [mean Sn—C 2.117 (11) Å] and the axial positions occupied by O atoms from different carboxylate groups, with significantly different Sn—O bond lengths [2.207 (5) and 2.358 (6) Å]. The structure forms a polymeric chain of complex molecules linked via carboxylate moieties.     

2,3,6,7‐Tetra­hydroxy‐9,10‐di­methyl‐9,10‐di­hydro‐9,10‐ethano­anthracene bis(1,4‐dioxane) solvate

2,3,6,7‐Tetra­hydroxy‐9,10‐di­methyl‐9,10‐di­hydro‐9,10‐ethano­anthracene crystallizes with 1,4‐dioxane to give a bis‐solvate, C₁₈H₁₈O₄·2C₄H₈O₂. The bis­(catechol) mol­ecule is located on a twofold axis and the two aromatic rings form a dihedral angle of 130.61 (4)°. Hydro­gen bonds are formed between the hydroxyl groups and either a neighbouring bis­(catechol) mol­ecule or the ether‐O atom of a dioxane mol­ecule.     

[Cd{C2(COO)2}(H2O)3]·H2O,the first cadmium salt of acetylenedicarboxylic acid

In catena‐poly­[[[tri­aqua­cadmium(II)]‐μ‐acetyl­enedi­carboxyl­ato‐κ⁴O,O′:O′′,O′′′] hydrate], {[Cd(C₄O₄)(H₂O)₃]·­H₂O}_n, the Cd^II atom is coordinated by two bidentate carboxyl­ate groups and three water mol­ecules, thus forming a sevenfold coordination polyhedron with all atoms located on general sites. These polyhedra are connected by the bifunctional acetyl­enedi­carboxyl­ate ligands, forming zigzag chains running parallel to [120]. Hydro­gen bonds, which involve the non‐coordinated water mol­ecule, connect these chains to form a three‐dimensional framework.     

Poly­[[di­aqua­cobalt(II)]‐μ‐4,4′‐bi­pyridine‐κ2N:N′‐μ‐p‐phenyl­enebis­(oxy­acetato)‐κ2O:O′]

The title compound, [Co^II(C₁₀H₈O₆)(C₁₀H₈N₂)(H₂O)₂]_n, was obtained by the hydro­thermal reaction of CoSO₄ with benzene‐1,4‐dioxy­di­acetate [systematic name: p‐phenyl­ene­bis­(oxy­acetate)] and 4,4′‐bi­pyridine (4,4′‐bpy). The Co atom lies at an inversion center and the benzene‐1,4‐dioxydiacetate and 4,4′‐bipyridine moieties lie about other inversion centers. The benzene‐1,4‐dioxydiacetate ligands bridge the octahedral Co^II coordination centers, forming a one‐dimensional zigzag chain. The chains are further bridged by 4,4′‐bpy ligands, forming a novel two‐dimensional supramolecular architecture. Hydro­gen‐bonding interactions between the coordinated water mol­ecules and the carboxyl­ate O atoms lead to the formation of a three‐dimensional network structure.     

Synthetic hydro­cerussite, 2PbCO3·Pb(OH)2, by X‐ray powder diffraction

Synthetic hydro­cerussite [trilead dihydroxide dicarbonate, Pb₃(CO₃)₂(OH)₂] can be easily obtained, as a white powder, by the action of carbon dioxide and water on either lead or litharge at pH 4–5. This compound is also found in lead corrosion technological products as a fine‐grained phase. Abinitio crystal structure determination was carried out on X‐ray powder diffraction data. The heavy‐atom method and the Patterson function helped determine the crystallographic model and the atom locations. The Rietveld fitting procedure was used for the final refinement. The atomic arrangement is closely related to the structures of other lead hydro­xide carbonates. The hydro­cerussite structure can be viewed as a sequence of two types of layers stacked along [001]. Layer A is composed of Pb and CO₃, and layer B is composed of Pb and OH. The stacking sequence is …BAABAA…     

NEt4OH·4H2O containing infinite hydro­xide–water ribbons

In tetraethyl­ammonium hydro­xide tetrahydrate, C₈H₂₀N⁺·­OH^?·­4H₂O, the array of mirror symmetric NEt₄⁺ cations gives rise to a system of parallel channels which are filled with hydrogen‐bonded anionic ribbons. The central part of each ribbon is constituted by a [OH^?(HOH)_4/2] spiro‐chain, with each hydro­xide ion accepting four strong linear hydrogen bonds [d(O?O) between 2.692 (1) and 2.727 (1) Å] but donating none. Additional (two‐coordinate) H₂O mol­ecules bridge between the (four‐coordinate) H₂O mol­ecules of the spiro‐chain [d(O?O) between 2.831 (1) and 2.835 (1) Å].     

Three complexes of bis(N‐methyl­benzo­hydro­xamato‐O,O′)copper(II)

The first single‐crystal studies of three bis‐transoid Cu–hydrox­amate salts, bis(3‐methoxy‐4,N‐dimethyl­benzo­hydrox­amato‐O,O′)copper(II), [Cu(C₁₀H₁₂NO₃)₂], bis(4‐chloro‐N‐methyl­benzo­hydro­xamato‐O,O′)copper(II), [Cu­(C₈­H₇­Cl­NO₂)₂], bis(N‐methyl‐3,5‐di­nitro­benzo­hydro­xamato‐O,O′)copper(II)–chloro­form (1/2), [Cu­(C₈­H₆­N₃O₆)₂]·­2CHCl₃, are presented. The Cu atom in each of the title compounds sits at a center of inversion and displays a nearly square‐planar geometry with the hydro­xamate‐O atoms connected to it in a syn configuration. The N atoms are in a transoid configuration. Each five‐membered Cu–hydro­xamate ring is planar, thus providing evidence that a planar N atom is present in each ring. The phenyl groups are twisted with respect to the hydro­xamate group by ～40–54°. The angular strain of the sp² carbonyl oxy­gen is significant (～10° from ideal).     

Dichlorobis(pyridine‐κN)bis(3,3,3‐trifluoropropyl‐κC1)tin(IV)

In the title compound, [Sn(C₃H₄F₃)₂Cl₂(C₅H₅N)₂], the Sn atom lies on an inversion centre and is octahedrally coordinated by two Cl atoms, two tri­fluoro­propyl groups and two N atoms in an all‐trans configuration. The electronegative tri­fluoro­propyl groups increase the electrophilic properties of the Sn atom, and the Sn—Cl and Sn—N bonds are shortened in comparison with those reported for analogous compounds.     

Hydro­gen‐bonding patterns in cis‐4‐ammonio­cyclo­hexane­carboxyl­ate hemihydrate

In the title compound, C₇H₁₃NO₂·0.5H₂O, cis‐4‐amino­cyclo­hexane­carboxylic acid exists as a zwitterion and co‐crystallizes with water mol­ecules in a 2:1 amino acid–water ratio. The cyclo­hexane ring adopts a chair conformation, with the carboxyl­ate and ammonium groups in axial and equatorial positions, respectively. The basic motif in the crystal structure is a sandwich structure, formed by two amino acid units linked by head‐to‐tail hydrogen bonds. Hydro­gen bonds of the type N⁺—H⋯O—C—O⁻ link these motifs, forming helicoidally extended chains running along the c axis. The water molecule lies on a twofold axis and interacts with the chains by means of O—H⋯O hydrogen bonds.     

α‐Onocerin chloro­form hemisolvate

The triterpenoid natural product α‐onocerin [8,14‐secogammacera‐8(26),14(27)‐diene‐3,21‐diol], determined here as the chloro­form hemisolvate, C₃₀H₅₀O₂·0.5CHCl₃, consists of two independent symmetric trans‐decalin C₁₅ building blocks. Hydro­gen bonds between the hydroxyl groups form an infinite two‐dimensional network perpendicular to the c axis.     

Head‐to‐head dimers in the zwitterion of 1‐hydroxy‐3‐(pyrrolidin‐1‐yl)pro­pyl­idene‐1,1‐bis­phospho­nic acid (EB 1053)

The title compound, 1‐hydroxy‐1‐phospho­no‐3‐(1‐pyr­rol­idin­io)­propyl­idene‐1‐phospho­nate, C₇H₁₇NO₇P₂, is a member of the bis­phospho­nate class of drugs. As a zwitterion, it possesses a negative charge on one of the PO₃ groups and a positive charge on the pyrrolidine N atom. A zwitterion makes a contact with a neighbouring ion through the hydroxyl O atom and two phospho­nyl O atoms, one each from two different PO₃ groups. Hydro­gen bonding involves O—H⋯O and N—H⋯O interactions; the former are involved in the formation of head‐to‐head dimers, while the latter join the dimers into a chain running along the crystallographic b axis.     

A two‐dimensional manganese(II) coordination polymer: poly­[[di­aqua­manganese(II)]‐μ‐4,4‐bi­pyridine‐κ2N:N′‐μ‐(p‐phenyl­ene­dioxy­diacetato)‐κ2O:O′]

In the title two‐dimensional coordination polymer, [Mn(1,4‐BDOA)(4,4‐bipy)(H₂O)₂]_n [1,4‐BDOA²⁻ is the p‐phenyl­ene­dioxy­di­acetate dianion (C₁₀H₈O₆) and 4,4‐bipy is 4,4‐bi­pyridine (C₁₀H₈N₂)], each Mn^II atom displays octahedral coordination by two O atoms of the 1,4‐BDOA²⁻ groups, two N atoms of the 4,4‐bipy ligands and two solvent water mol­ecules. The Mn^II atom, 4,4‐bipy ligand and 1,4‐BDOA²⁻ group occupy different inversion centres. Adjacent Mn^II atoms are bridged by 1,4‐BDOA²⁻ groups and 4,4‐bipy ligands, forming a two‐dimensional network with Mn⋯Mn separations of 11.592 (2) and 11.699 (2) Å. Hydro­gen bonds from a water O—H group link the layers in the third dimension.     

On the short carbonyl bond in bis[μ‐1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxido‐κ2N:O]bis{[1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxido‐κN]bis(imidazole)copper(II)}

The short carbonyl bond in the title compound, [Cu₂(C₇H₄­NO₃S)₄(C₃H₄N₂)₄] [Liu, Huang, Li & Lin (1991). Acta Cryst. C 47 , 41–43], is an artifact of disorder in the iso­thia­zol‐3(2H)‐one 1,1‐dioxide part of the 1,2‐benziso­thia­zol‐3(2H)‐one entity. In the present redetermination, all bond dimensions in the centrosymmetric dinuclear mol­ecule are normal. The five‐coordinate Cu atom shows trigonal–bipyramidal coordination. Hydro­gen bonds from the imidazole donor ligand link adjacent mol­ecules into a two‐dimensional layer structure.