(R)‐1‐Phenyl­ethyl­ammonium 6‐amino‐5‐nitro­pyrimidine‐2,4(1H,3H)‐dionate (R)‐1‐phenyl­ethyl­amine hemisolvate: hydrogen‐bonded sheets of ions with pendent solvent mol­ecules

In the title compound, 2C₈H₁₂N⁺·2C₄H₃N₄O₄⁻·C₈H₁₁N, the anions are linked by paired N—H⋯N hydrogen bonds [H⋯N = 2.07 and 2.11 Å, N⋯N = 2.942 (3) and 2.978 (3) Å and N—H⋯N = 173 and 170°] and by paired N—H⋯O hydrogen bonds [H⋯O = 1.98 and 2.05 Å, N⋯O = 2.855 (3) and 2.917 (3) Å, and N—H⋯O = 173 and 167°] into chains of rings. These chains are linked into sheets by further N—H⋯O hydrogen bonds in which all of the donors are provided by the cations [H⋯O = 1.83–2.17 Å, N⋯O = 2.747 (3)–2.965 (3) Å and N—H⋯O = 141–168°]. The neutral amine molecule is pendent from the sheet and is linked to it by a single N—H⋯N hydrogen bond [H⋯N = 2.00 Å, N⋯N = 2.901 (3) Å and N—H⋯N = 175°].     

Ammonium N‐(6‐amino‐3,4‐di­hydro‐3‐methyl‐5‐nitro­so‐4‐oxopyrimidin‐2‐yl)­glycinate monohydrate forms hydrogen‐bonded bilayers

In the title compound, NH₄⁺·C₇H₈N₅O₄⁻·H₂O, the independent components are linked into bilayers by an extensive series of two‐centre N—H⃛O hydrogen bonds [H⃛O = 1.85–1.96 Å, N⃛O = 2.776 (2)–2.840 (2) Å and N—H⃛O = 149–172°], and by asymmetric three‐centre N—H⃛(O)₂, O—H⃛(N,O) and O—H⃛(O)₂ hydrogen bonds.     

6‐Amino‐2‐(3,4‐di­methoxy­benzyl­amino)‐3‐methyl‐5‐nitro­so­pyrimidin‐4(3H)‐one: hydrogen‐bonded sheets form interdigitated bilayers

Molecules of the title compound, C₁₄H₁₇N₅O₄, exhibit a highly polarized molecular–electronic structure. The mol­ecules are linked into sheets by two N—H⋯O hydrogen bonds [H⋯O = 2.03 and 2.02 Å, N⋯O = 2.836 (2) and 2.887 (2) Å, and N—H⋯O = 153 and 168°], augmented by a single C—H⋯O hydrogen bond [H⋯O = 2.47 Å, C⋯O = 3.403 (2) Å and C—H⋯O = 166°]. Pairs of sheets, related by inversion, form bilayers with interdigitated di­methoxy­benzyl substituents, weakly linked by a further C—H⋯O interaction [H⋯O = 2.50 Å, C⋯O = 3.350 (2) Å and C—H⋯O = 146°].     

Tetra­aqua(5‐fluoro­uracil‐1‐acetato‐O)copper(II) tetra­hydrate

In the title complex, [Cu(C₆H₄FN₂O₄)₂(H₂O)₄]·4H₂O, the Cu atom is located in the centre of a distorted octahedral geometry. The coordination atoms are six O atoms provided by two carboxyl­ate groups [coordinated in a monodentate mode, with Cu—O = 1.9551 (10) Å] and four water mol­ecules [Cu—O = 1.9241 (13) and 2.5771 (14) Å]. In addition, one intramolecular hydrogen bond and ten intermolecular hydrogen bonds make up a three‐dimensional network.     

Tripotassium tris­(oxalato‐κ2O,O′)­aluminate bis(hydrogen peroxide) hydrate,the first example of a cyclic hydrogen‐bonded H2O2 dimer

In addition to associating into cyclic hydrogen‐bonded dimers [O⋯O = 2.663 (1) and 2.914 (1) Å], each hydrogen peroxide mol­ecule in the title structure, K₃[Al(C₂O₄)₃]·1.75H₂O₂·0.25H₂O, hydrogen bonds to a neighbouring oxalate ligand [O⋯O = 2.700 (1) and 2.730 (1) Å] and coordinates to two K⁺ ions [K⋯O = 2.6620 (9)–2.8380 (7) Å].     

2‐Amino‐5‐nitro‐4,6‐dipiperidinopyrimidinium hydrogen­sulfate monohydrate: hydrogen‐bonded sheets containing highly distorted cations

In the title compound, C₁₄H₂₃N₆O₂⁺·HSO₄⁻·H₂O, the pyrimidinium ring of the cation adopts a twist‐boat conformation, induced by steric clashes between adjacent ring substituents; the anions and the water mol­ecules are linked by three O—H⃛O hydrogen bonds [H⃛O = 1.70–1.78 Å, O⃛O = 2.548 (2)–2.761 (2) Å and O—H⃛O = 161–168°] into chains of edge‐fused R(12) rings, which are linked into sheets by the cations, via three N—H⃛O hydrogen bonds [H⃛O = 1.96–2.17 Å, N⃛O = 2.820 (2)–2.935 (2) Å and N—H⃛O = 145–173°].     

Trigonal–planar silver coordination in (3,5‐di­nitro­benzoato)­bis­(tri­phenyl­phosphine)­silver(I)

The three‐coordinate Ag atom in the title compound, [Ag(C₇H₃N₂O₆)(C₁₈H₁₅P)₂], shows trigonal–planar coordination [P—Ag—P = 147.1 (1)° and Σ_Ag = 359.0 (3)°]. Adjacent mol­ecules are linked through the O atoms of adjacent nitro groups [Ag?O = 3.205 (3) and 3.302 (4) Å] into a zigzag chain running parallel to the c axis.     

2,6‐Bis[bis(2‐pyridiniomethyl)aminomethyl]‐4‐tert‐butylphenol dichloride diperchlorate hydrate

The title compound, C₃₆H₄₄N₆O⁴⁺·2Cl^?·2ClO₄^?·0.132H₂O, is shown to be protonated at all the pyridine N atoms; the two chloride ions are hydrogen bonded to three pyridine N atoms and to the phenolic O atom of the same cation [Cl?N = 3.045 (2)–3.131 (2) Å and Cl?O = 2.938 (2) Å], and the remaining pyridine N atom is hydrogen bonded to the phenolic O atom [N?O = 2.861 (2) Å]. The mean value of the C—N—C angle of the protonated pyridine rings is 123.4 (1)°, which is significantly larger than that found for unprotonated pyridine rings.     

Tetraaqua­bis[2‐(4‐pyridyl)ethanesul­fonato‐N]­zinc(II)

The title compound, [Zn(C₇H₈NO₃S)₂(H₂O)₄], has an octahedral coordination around the central Zn atom composed of two axial N atoms from the pyridine ligands and four equatorial O atoms of water mol­ecules, forming a monomeric centrosymmetric complex. The two Zn—N bond distances are 2.102 (3) Å, while the four Zn—O bond distances range from 2.114 (2) to 2.167 (2) Å. Packing is determined by hydrogen bonds formed by the water mol­ecules. The sulfonate group does not take part in coordination to the Zn atom.     

2,2′‐Methyl­enebis(3‐hydroxy‐5,5‐di­methyl­cyclo­hex‐2‐en‐1‐one)

The title compound, C₁₇H₂₄O₄, crystallizes with two independent mol­ecules, both lying across twofold rotation axes in space group Pccn, in a unit cell whose dimensions closely mimic those of a tetragonal cell. Each mol­ecule contains paired O—H⋯O hydrogen bonds [H⋯O = 1.81 and 1.83 Å, O⋯O = 2.640 (2) and 2.642 (2) Å, and O—H⋯O = 168 and 162°].     

π‐Stacked hydrogen‐bonded dimers in 2‐(2‐nitro­phenyl­amino­carbonyl)­benzoic acid,and hydrogen‐bonded sheets in orthorhombic and monoclinic polymorphs of 2‐(4‐nitro­phenyl­amino­carbonyl)­benzoic acid

Molecules of 2‐(2‐nitrophenylaminocarbonyl)benzoic acid, C₁₄H₁₀N₂O₅, are linked into centrosymmetric R(8) dimers by a single O—H⋯O hydrogen bond [H⋯O = 1.78 Å, O⋯O = 2.623 (2) Å and O—H⋯O = 178°] and these dimers are linked into sheets by a single aromatic π–π stacking interaction. The isomeric compound 2‐(4‐nitrophenylaminocarbonyl)benzoic acid crystallizes in two polymorphic forms. In the orthorhombic form (space group P2₁2₁2₁ with Z′ = 1, crystallized from ethanol), the mol­ecules are linked into sheets of R(22) rings by a combination of one N—H⋯O hydrogen bond [H⋯O = 1.96 Å, N⋯O = 2.833 (3) Å and N—H⋯O = 171°] and one O—H⋯O hydrogen bond [H⋯O = 1.78 Å, O⋯O = 2.614 (3) Å and O—H⋯O = 173°]. In the monoclinic form (space group P2₁/n with Z′ = 2, crystallized from acetone), the mol­ecules are linked by a combination of two N—H⋯O hydrogen bonds [H⋯O = 2.09 and 2.16 Å, N⋯O = 2.873 (4) and 2.902 (3) Å, and N—H⋯O = 147 and 141°] and two O—H⋯O hydrogen bonds [H⋯O = 1.84 and 1.83 Å, O⋯O = 2.664 (3) and 2.666 (3) Å, and O—H⋯O = 166 and 174°] into sheets of some complexity. These sheets are linked into a three‐dimensional framework by a single C—H⋯O hydrogen bond [H⋯O = 2.45 Å, C⋯O = 3.355 (4) Å and C—­H⋯O = 160°].     

Bis­(pyridine­carboxyl­ato‐O,N)­(pyri­dine­carboxyl­ic acid‐O,N)­manganese(III) hy­drox­ide

The title complex, [Mn(C₅H₄NCO₂)₂(C₅H₄NCOOH)]OH, consists of a cation and a hydro­xide ion. The Mn atom is coordinated by three N atoms and three O atoms from three pyridine­carboxyl­ate ligands, and has a distorted octahedral geometry, with Mn—N distances ranging from 2.157 (1) to 2.233 (1) Å and Mn—O distances from 1.910 (1) to 1.927 (4) Å. One ligand is protonated as the acid form. This forms one of two independent hydrogen bonds, to the anion.     

catena‐Poly­[[(di‐2‐pyridyl­amine)­silver(I)]‐μ‐nicotinato] and catena‐poly­[[(di‐2‐pyridyl­amine)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato]

In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐nico­tinato‐κ²N:O], [Ag(C₆H₄NO₂)(C₁₀H₉N₃)]_n, the Ag^I atom is tetracoordinated by two N atoms from the di‐2‐pyridyl­amine (BPA) ligand [Ag—N = 2.3785 (18) and 2.3298 (18) Å] and by one N atom and one carboxyl­ate O atom from nicotinate ligands [Ag—N = 2.2827 (15) Å and Ag—O = 2.3636 (14) Å]. Bridging by nicotinate N and O atoms generates a polymeric chain structure, which extends along [100]. The carboxyl O atom not bonded to the Ag atom takes part in an intrachain C—H⋯O hydrogen bond, further stabilizing the chain. Pairs of chains are linked by N—H⋯O hydrogen bonds to generate ribbons. There are no π–π interactions in this complex. In catena‐poly­[[(di‐2‐pyridyl­amine‐κ²N,N′)silver(I)]‐μ‐2,6‐di­hydroxy­benzoato‐κ²O¹:O²], [Ag(C₇H₅O₄)(C₁₀H₉N₃)]_n, the Ag^I atom has a distorted tetrahedral coordination, with three strong bonds to two pyridine N atoms from the BPA ligand [Ag—N = 2.286 (5) and 2.320 (5) Å] and to one carboxyl­ate O atom from the 2,6‐di­hydroxy­benzoate ligand [Ag—O = 2.222 (4) Å]; the fourth, weaker, Ag‐atom coordination is to one of the phenol O atoms [Ag⋯O = 2.703 (4) Å] of an adjacent moiety, and this interaction generates a polymeric chain along [100]. Pairs of chains are linked about inversion centers by N—H⋯O hydrogen bonds to form ribbons, within which there are π–π interactions. The ribbons are linked about inversion centers by pairs of C—H⋯O hydrogen bonds and additional π–π interactions between inversion‐related pairs of 2,6‐di­hydroxy­benzoate ligands to generate a three‐dimensional network.     

trans‐Di­aqua­bis­(thio­semicarb­azido‐κ2N,S)­nickel(II) dimaleate dihydrate

In the title compound, [Ni(CH₅N₃S)₂(H₂O)₂](C₄H₃O₄)₂·2H₂O, the Ni atom lies on a center of symmetry and is coordinated by N and S atoms from two thio­semicarbazide ligands and the O atoms of two water mol­ecules in a distorted octahedral geometry. In the asymmetric unit, the three components are linked together by one O—H⋯O and two N—H⋯O hydrogen bonds. The packing is built from molecular ribbons parallel to the b direction, stabilized by intramolecular hydrogen bonds, and by one N—H⋯S and two N—H⋯O intermolecular hydrogen bonds. The ribbons are further connected into columns by N—H⋯O interactions and then into a three‐dimensional network by three O—H⋯O hydrogen bonds.     

Aqua­(phthalocyaninato)­magnesium

The title compound, [Mg(C₃₂H₁₆N₈)(H₂O)], crystallizes with two MgPc(H₂O) mol­ecules (Pc is phthalocyaninate) in the asymmetric unit. The geometries of the two mol­ecules are very similar, with the Mg atoms each 4+1‐coordinated by four iso­indole N atoms at the base and by the O atom of the water mol­ecule. The Mg atoms are displaced by 0.447 (1) and 0.468 (1) Å from the basal coordination planes towards the water O atoms. O—H?N hydrogen bonds form dimers stacked along the b axis in a herring‐bone fashion.     

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].     

Symmetric hydrogen bonding in dimethyl­ammonium hydrogen diphenyl­diphospho­nate

In the title compound, C₂H₈N⁺·C₁₂H₁₁O₅P₂⁻, pairs of hydrogen diphenyl­diphospho­nate anions form dimers across a twofold axis, with two symmetric O⋯H⋯O hydrogen bonds [O⋯O = 2.406 (3) and 2.418 (3) Å]. The 12‐membered ring thus formed has crystallographic 2 and quasi‐222 symmetry. Cations on either side of the ring form N—H⋯O hydrogen bonds to the four extraannular O atoms, with N⋯O distances of 2.765 (2) and 2.748 (3) Å.     

Cocrystallization of adamantane‐1,3‐dicarboxylic acid and 4,4′‐bipyridine

The cocrystallization of adamantane‐1,3‐dicarboxylic acid (adc) and 4,4′‐bipyridine (4,4′‐bpy) yields a unique 1:1 cocrystal, C₁₂H₁₆O₄·C₁₀H₈N₂, in the C2/c space group, with half of each molecule in the asymmetric unit. The mid‐point of the central C—C bond of the 4,4′‐bpy molecule rests on a center of inversion, while the adc molecule straddles a twofold rotation axis that passes through two of the adamantyl C atoms. The constituents of this cocrystal are joined by hydrogen bonds, the stronger of which are O—H...N hydrogen bonds [O...N = 2.6801 (17) Å] and the weaker of which are C—H...O hydrogen bonds [C...O = 3.367 (2) Å]. Alternate adc and 4,4′‐bpy molecules engage in these hydrogen bonds to form zigzag chains. In turn, these chains are linked through π–π interactions along the c axis to generate two‐dimensional layers. These layers are neatly packed into a stable crystalline three‐dimensional form via weak C—H...O hydrogen bonds [C...O = 3.2744 (19) Å] and van der Waals attractions.     

7‐Carboxyl­ato‐8‐hydroxy‐2‐methyl­quinolinium monohydrate and 7‐carboxy‐8‐hydroxy‐2‐methyl­quinolinium chloride monohydrate at 100 K

Both 7‐carboxyl­ato‐8‐hydroxy‐2‐methyl­quinolinium monohydrate, C₁₁H₉NO₃·H₂O, (I), and 7‐carboxy‐8‐hydroxy‐2‐methyl­quinolinium chloride monohydrate, C₁₁H₁₀NO₃⁺·Cl⁻·H₂O, (II), crystallize in the centrosymmetric P space group. Both compounds display an intramolecular O—H⋯O hydrogen bond involving the hydroxy group; this hydrogen bond is stronger in (I) due to its zwitterionic character [O⋯O = 2.4449 (11) Å in (I) and 2.5881 (12) Å in (II)]. In both crystal structures, the HN⁺ group participates in the stabilization of the structure via intermolecular hydrogen bonds with water mol­ecules [N⋯O = 2.7450 (12) Å in (I) and 2.8025 (14) Å in (II)]. In compound (II), a hydrogen‐bond network connects the Cl⁻ anion to the carboxylic acid group [Cl⋯O = 2.9641 (11) Å] and to two water mol­ecules [Cl⋯O = 3.1485 (10) and 3.2744 (10) Å].     

4‐Amino‐2,6‐di­methoxy­pyrimidine: hydrogen‐bonded sheets of R22(8) and R66(28) rings,reinforced by an aromatic π–π‐stacking interaction

Molecules of the title compound, C₆H₉N₃O₂, are linked by an N—H⃛O hydrogen bond [H⃛O = 2.29 Å, N⃛O = 3.169 (2) Å and N—H⃛O = 173°] and an N—H⃛N hydrogen bond [H⃛N = 2.12 Å, N⃛N = 2.999 (2) Å and N—H⃛N = 175°] into sheets containing centrosymmetric R(8) and R(28) rings; the sheets are reinforced by a single aromatic π–π‐stacking interaction.