Diacetatobis­(tri­methyl­ene­thio­urea)­zinc(II) monohydrate

In the title compound, [Zn(CH₃COO)₂(C₄H₈N₂S)₂]·H₂O, the Zn atom is tetrahedrally coordinated in the ZnO₂S₂ form. N—H?O and O—H?O intramolecular and intermolecular hydrogen bonds are formed by the four N atoms and the water mol­ecule. N—H?O intermolecular hydrogen bonds and C—H?S and C—H?O intermolecular interactions interconnect columns formed by the mol­ecules into layers. Adjacent layers are then linked by other N—H?O and O—H?O intermolecular hydrogen bonds to form a three‐dimensional framework throughout the structure. The orientations of the acetate planes are such that the Zn atom lies within them.     

Hexa­methyl­enetetra­mine–4‐nitro­catechol–water (1/2/1)

In the title adduct, 1,3,5,7‐tetra­aza­tri­cyclo[3.3.1.1^3,7]dec­ane–4‐nitro­benzene‐1,2‐diol–water (1/2/1), C₆H₁₂N₄·2C₆H₅NO₄·H₂O, the hexa­methyl­ene­tetra­mine mol­ecule acts as an acceptor of intermolecular O—H?N hydrogen‐bonding interactions from the water mol­ecule and the hydroxy groups of one of the two symmetry‐independent 4‐nitro­catechol mol­ecules. The structure is built from molecular layers which are stabilized by three intermolecular O—H?O, two intermolecular O—H?N and four intermolecular C—H?O hydrogen bonds. The layers are further interconnected by one additional intermolecular O—H?N and two intermolecular C—H?O hydrogen bonds.     

fac‐Bromo­tri­carbonyl­[2‐(2‐pyridylmethyl)‐2,3‐di­hydro‐1H‐isoindol‐1‐one]­rhenium(I) methanol solvate

The structure of the title compound, fac‐[ReBr(C₁₄H₁₂N₂O)(CO)₃]·CH₄O, consists of neutral mononuclear mol­ecular units of distorted octahedral geometry, with the three carbonyl donors in a facial orientation. The remaining coordination sites are occupied by the Br atom, the pyridine N atom and the ketone O‐atom donor of the ligand. The mol­ecules pack in stacks of antiparallel tapes, with a network of classical (O—H⋯Br) and non‐classical (C—H⋯O) hydrogen bonds between the methanol solvent mol­ecule and the complex mol­ecule.     

Chlor­amine‐B sesquihydrate

In the title compound, sodium N‐chloro­benzene­sulfon­amide sesquihydrate, Na⁺·C₆H₅ClNO₂S^?·1.5H₂O, the sodium ion exhibits octahedral coordination by O atoms from three water mol­ecules and by three sulfonyl O atoms of three different N‐­chloro­benzene­sulfon­amide anions. A two‐dimensional polymeric layer consists of units, each comprising two face‐sharing octahedra which share four corners with four other such units, the layer running parallel to the ab plane. The water mol­ecules participate in hydrogen bonds of the types O—H?O, O—H?N and O—H?Cl.     

N,N′‐Bis(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide and N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide

The mol­ecules of N,N′‐bis­(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyl­dicarboxamide, [Fe(C₁₂H₁₁N₂O)₂], contain intra­molecular N—H⋯N hydrogen bonds and are linked into sheets by three independent C—H⋯O hydrogen bonds. The mol­ecules of the isomeric compound N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide lie across inversion centres, and the mol­ecules are linked into sheets by a combination of N—H⋯N hydrogen bonds and π–π stacking inter­actions between pyridyl groups.     

N‐(2‐Amino‐1,6‐di­hydro‐5‐nitro­so‐6‐oxopyrimidin‐4‐yl)‐l‐isoleucine–water (4/1): interplay of molecular and supramolecular structures

In the title compound, 2C₁₀H₁₅N₅O₄·0.5H₂O, there are two independent mol­ecules of the pyrimidinyl­isoleucine in general positions and a water mol­ecule lying on a twofold rotation axis. The bond lengths within the organic moieties demonstrate significant polarization of the electronic structure. Each of the organic mol­ecules participates in 12 intermolecular hydrogen bonds, of O—H?O and N—H?O types, while the water mol­ecule acts as a double donor and as a double acceptor of O—H?O hydrogen bonds. The organic components are linked by the hydrogen bonds into a single three‐dimensional framework, reinforced by the water mol­ecules.     

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.     

Hydro­gen‐bonded molecular ladders in trans‐1,2‐bis(2‐nitro­anilino)­cyclo­hexane

Crystals of the title compound, C₁₈H₂₀N₄O₄, contain equal numbers of (R,R) and (S,S) mol­ecules, but these are not precise enantiomorphs, neither are they related by crystallographic symmetry; in addition, each mol­ecule exhibits approximate, but not exact, twofold rotational symmetry. There are intramolecular N—H?O hydrogen bonds [N?O 2.609 (4)–2.638 (5) Å; N—H?O 125–132°] and the mol­ecules are linked into molecular ladders by C—H?O hydrogen bonds [C?O 3.306 (6)–3.386 (6) Å; C—H?O 146–160°].     

catena‐Poly­[[di­aqua­lithium(I)]‐μ‐[9H‐purine‐2,6(1H,3H)‐dionato‐O2:N7]]

In the title compound, [Li(C₅H₃N₄O₂)(H₂O)₂]_n, the coordinate geometry about the Li⁺ ion is distorted tetrahedral and the Li⁺ ion is bonded to N and O atoms of adjacent ligand mol­ecules forming an infinite polymeric chain with Li—O and Li—N bond lengths of 1.901 (5) and 2.043 (6) Å, respectively. Tetrahedral coordination at the Li⁺ ion is completed by two cis water mol­ecules [Li—O 1.985 (6) and 1.946 (6) Å]. The crystal structure is stabilized both by the polymeric structure and by a hydrogen‐bond network involving N—H?O, O—H?O and O—H?N hydrogen bonds.     

Copper(II) and zinc(II) complexes of pyridine‐2,6‐di­carboxyl­ic acid

The title compounds, bis­(pyridine‐2,6‐di­carboxyl­ato‐N,O,O′)copper(II) monohydrate, [Cu(C₇H₄NO₄)₂]·H₂O, andbis(pyridine‐2,6‐dicarboxylato‐N,O,O′)zinc(II) trihydrate, [Zn(C₇H₄NO₄)₂]·3H₂O, have distorted octahedral geometries about the metal centres. Both metal ions are bonded to four O atoms and two pyridyl‐N atoms from the two terdentate ligand mol­ecules, which are nearly perpendicular to each other. The copper(II) complex has twofold crystallographic symmetry and contains two different ligand mol­ecules, one of which is neutral and another doubly ionized. In contrast, the zinc(II) complex contains two identical singly ionized ligand mol­ecules. Both crystal structures are stabilized by O—H?O intermolecular hydrogen bonds between the complex and the water mol­ecules.     

Bis­[tris(2,2′‐bi­pyridine‐κ2N,N′)­ruthenium(II)] hexa­cyano­ferrate(III) chloride octahydrate

In the title compound, [Ru^II(C₁₀H₈N₂)₃]₂[Fe^III(CN)₆]Cl·8H₂O, the [Ru(bpy)₃]²⁺ (bpy is 2,2′‐bi­pyridine) cations and water mol­ecules afford intriguing microporous honeycomb layers, while the [Fe(CN)₆]³⁻ anions and the remainder of the water mol­ecules form anionic sheets based on extensive hydrogen‐bonding networks. The cationic and anionic layers alternate along the c axis. The Fe atom in [Fe(CN)₆]³⁻ lies on an inversion centre and the axial cyano ligands are hydrogen bonded to the water mol­ecules encapsulated within the micropores [N⋯O = 2.788 (5) Å], giving an unusual interpenetration between the cationic and anionic layers. On the other hand, the in‐plane cyano ligands are relatively weakly hydrogen bonded to the water mol­ecules [N⋯O = 2.855 (7) and 2.881 (8) Å] within the anionic sheets.     

dl‐Arginine monohydrate at 100 K

In the title compound, C₆H₁₄N₄O₂·H₂O, the α‐amino group is neutral. The molecular side chain including the guanidinium group is not fully extended, having a near gauche–gauche conformation [χ³ = 59.0 (1)°; χ⁴ = 72.8 (1)°]. The network of hydrogen bonds stabilizing the crystal lattice includes those formed between the deprotonated and negatively charged α‐carboxyl­ate groups and the positively charged amino groups of the guanidinium group of neighbouring mol­ecules. N—H?O=C and water‐mediated N—H?O hydrogen bonds link individual mol­ecules to produce pairs of spiral motifs laterally connected by N—H?O and C—H?O hydrogen bonds.     

2-[1-(Hydroxyimino)ethyl]-2,5,5-trimethylperhydropyrimidine–butane-2,3-dione monooxime (1/1)

The title compound, C₉H₁₉N₃O·C₄H₇NO₂, displays strong intramolecular O—H⃛N [O⃛N 2.6743 (13) Å] and N—H⃛N [N⃛N 2.6791 (15) Å] hydrogen bonds, and strong intermolecular O—H⃛N [O⃛N 2.7949 (15) Å] and N—H⃛O [N⃛O 3.0924 (16) Å] hydrogen bonds. This creates chains of per­hydro­pyrimidine mol­ecules, linked by hydrogen bonds. Each chain is linked to a partner chain, through hydrogen bonds to two butane-2,3-dione monooxime mol­ecules, in a structure reminiscent of a ladder.     

4‐[(2‐Chloro­phenyl)­diazenyl]‐6‐methoxy‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}cyclo­hexa‐3,5‐dien‐1(2H)‐one

The structure of the title compound, C₁₈H₂₀ClN₃O₅, displays the characteristic features of azo­benzene derivatives. Intramolecular N—H⋯O, weak intramolecular C—H⋯O, and intermolecular O—H⋯O and C—H⋯O interactions influence the conformation of the mol­ecules and the crystal packing. Intermolecular hydrogen bonds link the mol­ecules into infinite chains, and the title compound adopts the keto–amine tautomeric form. The azo­benzene moiety of the mol­ecule has a trans configuration. The mol­ecule is not planar, and the dihedral angle between the two phenyl rings is 35.6 (2)°.     

Ferrocene compounds. XXXIV. 1′‐(tert‐Butoxycarbonylamino)ferrocene‐1‐carboxylic acid

Heteroannularly substituted ferrocene derivatives can act as model systems for various hydrogen‐bonded assemblies of biomol­ecules formed, for instance, by means of O—H⋯O and N—H⋯O hydrogen bonding. The crystal structure analysis of 1′‐(tert‐butoxy­carbonyl­amino)­ferrocene‐1‐carbox­ylic acid, [Fe(C₁₀H₁₄NO₂)(C₆H₅O₂)] or (C₅H₄COOH)Fe(C₅­H₄NHCOOC(CH₃)₃, reveals two independent mol­ecules within the asymmetric unit, and these are joined into discrete dimers by two types of intermolecular hydrogen bonds, viz. O—H⋯O and N—H⋯O. The –COOH and –NHCOOR groups are archetypes for dimer formation via two eight‐membered rings. The O—H⋯O hydrogen bonds [2.656 (3) and 2.663 (3) Å] form a cyclic carboxylic acid dimer motif. Another eight‐membered ring is formed by N—H⋯O hydrogen bonds [2.827 (3) and 2.854 (3) Å] between the N—H group and an O atom of another carbamoyl moiety. The dimers are assembled in a herring‐bone fashion in the bc plane.     

N‐Propionylhydroxylamine forms a three‐dimensional hydrogen‐bonded framework structure

The title compound, N‐hydroxy­propan­amide, C₃H₇NO₂, crystallizes with Z′ = 3 in P2₁/c. The mol­ecules are linked by three N—H?O hydrogen bonds [N?O 2.8012 (16) to 2.8958 (15) Å; N—H?O 163 to 168°] and by three O—H?O hydrogen bonds [O?O 2.6589 (15) to 2.6775 (17) Å; O—H?O 165 to 177°] into a single three‐dimensional framework.     

Self‐assembled hydrogen‐bonded bilayers in 1,4‐diazabicyclo[2.2.2]octane–N‐(phosphonomethyl)iminodiacetic acid–water (1/1/1.5)

The title compound is a hydrated salt, 1,4‐diazo­nia­bi­cyclo­[2.2.2]­octane–N‐[(hydroxy­phosphinato)­methyl]­iminiodi­acetate–water (1/1/1.5), C₆H₁₄N₂²⁺·C₅H₈NO₇P^2?·1.5H₂O, in which one of the water mol­ecules lies across a twofold rotation axis in space group P2/n. The ionic components are linked into sheets by a combination of a three‐centre N—H?(O)₂ hydrogen bond and two‐centre O—H?O and N—H?O hydrogen bonds, and these sheets are pairwise linked by the water mol­ecules into bilayers, by means of further O—H?O hydrogen bonds.     

Host–guest inter­action in a thio­urea–dimethyl oxalate (2/1) complex at 300 and 100 K

The title complex, 2CH₄N₂S·C₄H₆O₄, is a host–guest system. The asymmetric unit consists of one complete thio­urea mol­ecule and one‐half of a dimethyl oxalate mol­ecule lying on an inversion centre. The host thio­urea mol­ecules are connected to form zigzag chains by N—H⋯S hydrogen bonds. The guest dimethyl oxalate mol­ecules provide O‐atom acceptors for N—H⋯O hydrogen bonds, thus inter­connecting the chains of thio­urea mol­ecules to form completely connected sheets. The reduction in temperature from 300 to 100 K leaves the structure unchanged and still isostructural with that previously determined for the analogous thio­urea–diethyl oxalate (2/1) complex. It does, however, induce closer packing of the mol­ecules, general shrinkage of the unit cell and shortening of the hydrogen bonds, these last two to the extent of 1–2%.     

Bis(2‐amino­pyridine‐N)­bis­(benzoato‐O)­zinc

The crystal structure of the title compound, [Zn‐(C₇H₅O₂)₂(C₅H₆N₂)₂], is built of monomeric [Zn(2‐apy)₂(OBz)₂] mol­ecules (apy is amino­pyridine and OBz is benzoate). The Zn atom lies on a twofold symmetry axis and adopts a slightly distorted tetrahedral coordination. The Zn?O distances to the non‐coordinated O atoms are long at 2.872 (3) Å. Each non‐ligating carbonyl O atom of the benzoate anion accepts one intramolecular and one intermolecular hydrogen bond from the amino group. The mol­ecules form a chain along the c axis through intermolecular N—H?O hydrogen bonds between the amino and carboxyl groups.     

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.