Synthesis and Crystal Structure Analysis of Methyl 2-Hydroxyimino-3-phenyl-propionate

Abstract  

As precursors of α-amino acids, methyl 2-hydroxyimino-3-phenyl-propionate (F.W. 193.20) was synthesized, characterized by ¹H NMR, IR, element analysis and confirmed by X-ray crystal structure analysis. This compound crystallizes in monoclinic class under the space group P2₁/c with cell parameters, a = 8.6435(17) Å, b = 5.4957(11) Å, c = 21.146(4) Å; β = 97.12(3)°, and Z = 4. The structure exhibits inter-molecular hydrogen bonds of the type O–H···N, O–H···O, C–H···O.     

Hydrogen Bonded 3D Supramolecular Architectures of Two Organic Salts Assembled from 2-Aminoheterocyclic Compounds and Phosphoric Acid

Abstract  

Two phosphate salts (2-aminopyrimidine): (phosphoric acid): H₂O [HL1⁺ (H₂PO₄) ⁻ ]·H₂O (1), and (4-phenylthiazol-2-amine): (phosphoric acid) [HL2⁺·(H₂PO₄)⁻] (2) based on 2-aminoheterocyclic compounds, 2-aminopyrimidine (L1), and 4-phenylthiazol-2-amine (L2) were prepared and structurally characterized by X-ray crystallography. Compound 1 crystallizes in the triclinic, space group P-1, with a = 6.2201(7) Å, b = 8.6139(9) Å, c = 9.4800(10) Å, α = 109.685(2)°, β = 106.3340(10)°, γ = 95.4450(10)°, V = 448.72(8) Å³, Z = 2. For 1, the cations were linked to each other via intermolecular C–H···N hydrogen bonds to form a 1-D chain structure running along the a-axis direction. The anions and the water molecules were connected alternatively along the a-axis direction through O–H···O hydrogen bonds to form a 1-D chain also. The cationic chains and the anionic chains were alternatively connected along the c-axis direction through N–H···O and C–H···O hydrogen bonds to form a 2D corrugated sheet. Adjacent sheets were combined together through π–π interaction to form double sheet. These double sheets were further joined together by O–H···O and N–H···O hydrogen bonds to produce a 3D network structure. Compound 2 crystallizes in the Orthorhombic, space group Pbca, with a = 10.1929(10) Å, b = 8.4406(9) Å, c = 27.589(2) Å, α = 90°, β = 90°, γ = 90°, V = 2373.6(4) Å³, Z = 8. In 2, the phosphates formed 1D chain along the b-axis through two P–O–H···O = P hydrogen bonds. The cations formed 1D zigzag chain along the b-axis direction under the CH–π interaction. The anionic chains were intercalated between two adjacent cationic chains through N–H···O, O–H···O, C–H···O, and O–S contacts. Such stacking repeated along the c-axis direction to form a 3D network structure.     

Synthesis, Spectroscopic Characterization and Crystal Structure of a New Acetyl phosphorylamidate P(O)[NHC(O)C6H4(4-NO2)][N(CH(CH3)2)(CH2C6H5)]2

Abstract  

A new acetyl phosphorylamidate P(O)[NHC(O)C₆H₄(4-NO₂)][N(CH(CH₃)₂)(CH₂C₆H₅)]₂ has been synthesized and characterized by elemental analysis, ¹H, ¹³C and ³¹P NMR, IR and single crystal X-ray diffraction. Single crystal X-ray analysis shows that it belongs to triclinic system, space group P[`1] P\bar{1} , with a = 10.5868(16) Å, b = 11.8058(18) Å, c = 12.4364(19) Å, α = 65.410(3)°, β = 67.492(4)°, γ = 85.879(3)°, V = 1,298.6(3) Å³, and Z = 2. The intermolecular PO···HN hydrogen bond makes H-bonded dimer of molecule with Ci symmetry. In the crystal network, the dimers are aggregated in the chain arrays through π-stacking between p-NO₂–C₆H₄–C(O)–NH– moieties. Moreover, weak C–H···O and C–H···π interactions exist in the crystal network.     

Synthesis,Crystal Structure and Hydrogen-Bonding Patterns in (RS)-1-Carbamoyl Pyrrolidine-2-Carboxylic Acid

Abstract  

The title compound, N-carbamoyl-dl-proline, C₆H₁₀N₂O₃, crystallizes in the triclinic P-1 space group with unit cell parameters a = 7.610 (4) Å, b = 9.259 (5) Å, c = 11.749 (7) Å, α = 110.294 (11)°, β = 101.304 (13)°, γ = 91.391 (16)°, with two crystallographically independent molecules in the asymmetric unit. The ureido and carboxyl groups are equatorial and axial to the pyrrolidine rings, respectively. The pyrrolidine rings adopt envelope and twisted conformations in the residue A and B, respectively. The molecules are joined by N–H···O and O–H···O hydrogen bonds into cyclic structures with graph set R ₂²(8), forming infinite chains parallel to the cb plane with graph set C ₂²(14), that are further connected via N–H···O hydrogen bonds into a three-dimensional network.     

Synthesis and Crystal Structure of a New Ion-Pair Complex Based on [Ni(tdas)<Subscript>2</Subscript>]<Superscript>2−</Superscript> Anion and Triphenylphosphinium Cation

Abstract  A new ion-pair complex, bis(1-benzyltriphenylphosphinium) bis(1,2,5-thiadiazole-3,4-dithiolato)nickelate(II), [BzTPP]₂[Ni(tdas)₂](1), has been prepared and characterized by elemental analyses, UV, IR, MS spectrum, molar conductivity and single crystal X-ray diffraction. The title complex crystallizes in the triclinic space group P-1, a = 9.098(1) Å, b = 9.666(1) Å, c = 29.573(3) Å, α = 83.81(1)°, β = 81.97(1)°, γ = 78.83(1)°, V = 2,517.5(4) ų, Z = 2. The unit cell contains two [BzTPP]⁺ and two halves of [Ni(tdas)₂]²⁻ anions in which the anion exhibits a quasi-planar structure. The [BzTPP]⁺ cation adopts a conformation where four phenyl rings are twisted to the C–C–P reference plane. The weak cation–cation C–H···π, π···π interactions and anion–cation C–H···N hydrogen bonds between the anion and cation play an important role in the stacking and stabilizing of the title complex. Graphical Abstract  The title new ion-pair complex, bis(1-benzyltriphenylphosphinium) bis(1,2,5-thiadiazole-3,4-dithiolato)nickelate(II), [BzTPP]₂[Ni(tdas)₂](1), contains two [BzTPP]⁺ and two halves of [Ni(tdas)₂]²⁻ anions in which the weak cation–cation C–H···π, π···π interactions and anion−cation C–H···N hydrogen bonds between the anion and cation play an important role in the stacking and stabilizing of the title complex.      

5-Pyridine 4-yl-3H-(1,3,4) Oxadiazole-2 Thione Hydrochloride Monohydrate, (I), and 4 [5-Ethylsulfanyl)-(1,3,4) Thiadiazole-2-yl]-Pyridinium Perchlorate, (II)

Abstract  

The title compounds C₇H₈ClN₃O₂S, (I), and C₉H₁₀ClN₃O₄S_2, (II), both crystallize in monoclinic space group P2₁ /c with unit cell parameters (I) a = 7.9402(7), b = 10.6312(9), c = 11.7626(10), ?, β = 99.271(5)°, Z = 4 and (II) a = 5.1439(2), b = 9.0636(4), c = 27.1814 (7), ?, β = 95.116(2)°, Z = 4. In (I) the molecule consists of a 5-pyridine-4-yl group bonded to the carbon atom at the 5 position of (1, 3, 4) oxadiazole-2 thione hydrochloride monohydrate. The angle between the mean planes of the oxadiazole and pyridine rings is 9.6(6)°. Crystal packing in (I) is stabilized by strong N–H···O hydrogen bonds in concert with a solvent water molecule and weak O–H···Cl, O–H···S, N–H···Cl intermolecular interactions. The crystal structure of compound (II) consists of 4 [5-ethylsulfanyl)-(1, 3, 4) thiadiazole-2-yl]-pyridinium perchlorate, (C₉H₁₀N₃S₂)⁺(ClO₄)⁻, cation–anion pairs, containing strong intermolecular N–H···O hydrogen bonds and weak C–H···O and N–H···O intermolecular interactions operating between the ionic species that form a cooperative hydrogen-bonded, infinite chain O–H···O–H···O–H network which generates a sheet motif structure in the unit cell. It is also supported by weak intermolecular Cg···Cg π–π and Cl–O···Cg π-ring interactions which gives additional support to molecular packing stability in the unit cell. Geometry optimized MOPAC AM1 computational calculations on each compound provides support to the structural features in their respective crystal structures.     

Crystal Structure of [4-(Methylsulfanyl)Phenyl]Acetic Acid

Abstract  

The title compound, C₉H₁₀O₂S, (I), crystallizes in the triclinic space group, P − 1, with unit cell parameters a = 6.2249(3), b = 7.3733(5), c = 19.5708(12), Å, α = 86.746(5)°, β = 88.682(5)°, γ = 86.988(5)°, Z = 4. The molecule consists of a methyl sulfanyl group bonded to benzyl acetic acid at the 4 position crystallizing with two molecules in the asymmetric unit. The carboxylic acid group from the acetic acid moiety in these two molecules forms a classic O–H···O hydrogen bonded dimer with O···O distances of 2.673(2) and 2.646(2) Å, in a R₂² (8) graph-set motif which link the molecules into pairs around inversion centers in the unit cell. The dihedral angles between the mean planes of the R₂² (8) graph-set motif with the mean planes of the two nearby benzyl groups within the same dimer in the unit cell are 64.1(6)° and 71.3(4)°, respectively. Within the same dimer the dihedral angle between the two benzyl groups is 45.2(1)°. The structure is supported by a weak intermolecular C–H···Cg π-ring interaction and gives support to molecular packing stability in the unit cell. Comparison to a MOPAC AM1 computational calculation provides support to these observations.     

Crystal Structure?4-(2,4-Dihydroxybenzylideneamino)-5-methyl-2H-1,2,4-triazol-3(4H)-one

Abstract  

The title compound (I), 4-(2,4-dihydroxybenzlideneamino)-5-methyl-2H-1,2,4-triazol-3(4H)-one was characterized by single crystal X-ray diffraction. This crystal is monoclinic, space group P2₁/c with a = 10.1447(7) ?, b = 7.0972(3) ?, c = 14.6726(10) ?, β = 98107(5)°, V = 1045.85(11) ?³, Z = 4, D _c = 1.487 g/cm³, F ₀₀ = 488, R = 0.039 and wR = 0.1025, S = 1.003, T = 293 (2) K. The title molecule is planar: the angle between the triazole ring and benzene ring is 179.1(1)°. The crystal structure contains two intramolecular (O–H···N and C–H···O) and three intermolecular interaction (O–H···N, N–H···O, and C–H···O). In addition, there is also π–π interactions.     

Low Temperature Crystal Structure of 5-Hydroxy-1,7-Bis-(4-Hydroxy-3-Methoxy-Phenyl)-Hepta-1,6-Dien-3-one

Abstract  

The title compound 5-Hydroxy-1,7-bis-(4-hydroxy-3-methoxy-phenyl)-hepta-1,6-dien-3-one crystallizes in orthorhombic space group Pca2₁ with two molecules in the asymmetric unit. The unit cell parameters are: a = 35.5368(8), b = 7.7799(2), c = 12.6796(3) ?, D _calc = 1.396 Mgm⁻³, V = 3505.6(2) ?³ and Z = 8. The two aromatic rings in both the molecules are found almost coplanar, their dihedral angles are 18.8° and 13.8°, respectively. The molecular packing is stabilized by strong O–H···O and C–H···O types of hydrogen bonding interactions. The keto and enol groups form an strong O–H···O intra-molecular interaction in both molecules of asymmetric unit. The molecular alignment in the crystal forming a staircase type of stacking through cross link intermolecular interactions.     

Synthesis,Crystal Structure and Characterizations of New 3,4,7,8-Tetrachloro-1,10-Phenanthroline Zn(II) Complex

Abstract  

A novel 3,4,7,8-tetrachloro-1,10-phenanthroline (Cl₄phen) Zn(II) complex has been synthesized. The complex, [Zn(Cl₄phen)₂(H₂O)₂](NO₃)₂·CH₃CH₂OH (1), has been identified and characterized by single crystal X-ray diffraction, elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence studies. Single crystal X-ray diffraction analysis reveals that complex (1) belongs to the monoclinic system, space group P2(1)/c, a = 10.061(2) Å, b = 18.924(4) Å, c = 18.189(4) Å, β = 100.94(3)°, and Z = 4. Complex (1) consists of cationic species [Zn(Cl₄phen)₂(H₂O)₂]²⁺, NO₃ ⁻ and CH₃CH₂OH. The zinc atom displays a distorted cis-N₄O₂ octahedral geometry. Via extended Zn–O–H···O–N–O···H–O–Zn bridge, every mononuclear unit is linked with other ones to form one-dimensional (1D) infinite chain of hydrogen bond system. Three-dimensional (3D) polymeric network arrangement was built via weak C–H···O and π-stacking interactions between Cl₄phen moieties. A solvent-dependency effect of complex (1) was observed in spectroscopic properties.     

Synthesis,Crystal Structure and Antibacterial Activity of 5-Bromonicotinic Acid [1-(4-Chlorophenyl)methylidene]hydrazide Monohydrate Methanol Solvate

Abstract  The compound 5-bromonicotinic acid [1-(4-chlorophenyl)methylidene]hydrazide monohydrate methanol solvate, derived from the condensation reaction of 5-bromonicotinic acid hydrazide with 4-chlorobenzaldehyde in a methanol solution, was synthesized and characterized by elemental analysis, IR spectrum, ¹H NMR and X-ray single crystal determination. The compound crystallizes in the triclinic space group P − 1 with unit cell dimensions a = 6.9360(14) ?, b = 10.070(2) ?, c = 12.267(3) ?, α = 84.39(3)°, β = 86.10(3)°, γ = 80.50(3)°, V = 839.8(3) Ǻ³, Z = 2, R ₁ = 0.0724, and wR ₂ = 0.1720. X-ray structure determination reveals that the compound has a trans configuration with respect to the C=N double bond or C–N single bond. In the crystal structure, molecules are linked through intermolecular O–H···N, O–H···O, and C–H···O hydrogen bonds, forming layers parallel to the ab plane. The preliminary biological tests show that the compound has excellent antibacterial activity. Index Abstract  The compound 5-bromonicotinic acid [1-(4-chlorophenyl)methylidene]hydrazide monohydrate methanol solvate, derived from the condensation reaction of 5-bromonicotinic acid hydrazide with 4-chlorobenzaldehyde in a methanol solution, was synthesized and characterized by elemental analysis, IR spectrum, ¹H NMR and X-ray single crystal determination. The molecule of the compound has a trans configuration with respect to the C=N double bond or C–N single bond. In the crystal structure, molecules are linked through intermolecular O–H···N, O–H···O, and C–H···O hydrogen bonds, forming layers parallel to the ab plane. The preliminary biological tests show that the compound has excellent antibacterial activity.      

Single Crystal XRD Structure Determination and Analysis of Bis(2,9-Dimethyl-1,10-Phenanthroline-κ2N,N′)(Sulfato-κ2O,O′)Nickel(II), Hydrate (NiNeo2SO4·H2O; Neo: 2,9-Dimethyl-1,10-Phenanthroline)

Abstract  

The title compound is monomeric with a Ni(II) hexacoordinated center. The coordination sphere is formed with four nitrogens from two neocuproine molecules and two oxygens from a sulfate ion that acts as a bidentate ligand. A water molecule completes the formula with an important role in the stabilization of the structure through the formation of O_W–H···O_S bridges, in which it acts as a donor and interactions of the type C_ar–H···O_W and C_Met–H···O_W, where it is an acceptor group (W: water; S: sulfate; ar: arene; Met: methyl). The compound is monoclinic, space group P2₁ /c with a = 14.4829(4) ?, b = 14.4563(4) ?, c = 12.1559(3) ?, β = 94.407(1)°, V = 2,537.55(12) ?³ and Z = 4. The structure was solved by direct methods with a conventional R (on F) = 0.0359 for 4841 reflexions with Fo > 4σ(Fo). Three levels of super-structural hierarchy can be identified in the crystal construction: (1) the primary structure corresponding to the molecular skeletons of their building blocks, the isolated complex itself and the water molecule, (2) an 1D supramolecular array that form chains through a non-covalent polymerization via interactions O_W–H···O_S, C_ar–H···O_W, C_ar–H···O_S and C_Met–H···O_W and (3) finally the 3D macroscopic conglomerate formed through inter-chains interactions C_ar–H···O_W, C_ar–H···O_S, C_Met–H···ar and offset stacked arene–arene.     

Rapid Eco-Friendly Synthesis and Structure of 3-Hydroxy-3-nitromethyl-1,3-dihydro-indol-2-one

Abstract  

3-Hydroxy-3-nitromethyl-1,3-dihydro-indol-2-one was synthesized from isatin by Henry reaction using an eco-friendly method and characterized by NMR and MS. The crystal structure was determined from single-crystal X-ray diffraction data. It crystallizes in the orthorhombic space group, Pbca, with unit cell dimensions a = 10.515 (2) Å, b = 7.3736 (14) Å, and c = 23.261 (4) Å. The two rings are coplanar and the angle between hydroxyl group and nitromethyl group is 109.07(9)°. In the crystal structure, intermolecular N–H···O and O–H···O hydrogen bonds are responsible for the formation of a 3-dimensional network. No intramolecular hydrogen bond exists.     

Synthesis,Crystal Structure and Optical Properties of a Three-Dimensional Supramolecule Assembled by a Dinuclear Neodymium Cluster

Abstract  

The reaction of isonicotinic acid (IN), sodium hydroxide, 1,10-phenanthroline (phen) and neodymium nitrate leads to the formation of a novel complex [Nd(phen)(IN)₂(NO₃)(H₂O)₂]₂ 1, which has been characterized by single crystal X-ray diffraction analysis: monoclinic, space group C2/c, with a = 24.93(2) Å, b = 9.452(3) Å, c = 21.406(5) Å, β = 97.87(2)°, and Z = 4. Complex 1 consists of a centrosymmetric dinclear molecule, and neodymium atoms are bridged by two carboxyl groups of two IN ligands. The dinuclear clusters of 1 are connected each other into a three-dimensional (3D) supramolecular framework, which is stabilized by O–H···O, O–H···N hydrogen bonds as well as π–π stacking interactions. Its electronic absorption and luminescence properties have also been investigated.     

Anchor Effect on Pedal Motion Observed in Crystal Phase of an Azobenzene Derivative

Abstract  

Some molecules having a molecular skeleton similar to that of stilbenes and azobenzenes show orientational disorder in the crystals due to pedal motion. Heretofore, the orientational disorder through pedal motion has been observed for the compounds containing only two aromatic rings in the absence of bulky substituent groups. Here we report that the pedal motion can be detected even in the presence of a bulky substituent group to which orientational disorder becomes invisible as a result of anchor effect arising from phenoxyphtalonitrile group. X-ray crystallographic analysis of the compound, C₂₃H₁₈N₄O, reveals the existence of partially overlapped two pedal conformers. The compound crystallizes in the monoclinic space group P2₁/c with a = 12.9429(11) Å, b = 8.5075(5) Å, c = 21.063(2) Å and β = 123.155(6)°. Major pedal conformer is stabilized by weak C–H···O type hydrogen bond and C–H···π type edge-to-face interactions in solid state. Quantum chemical calculations at B3LYP/6-311G+(d,p) level suggest that the stabilization of the compound decreases with increasing deviation from the planar geometry of trans-azobenzene fragment.     

Synthesis,Characterization and Crystal Structure Determination of a Hepta-coordinated Cadmium(II) Complex with Thiocyanato-bridges

Abstract  A new cadmium(II) complex [(C₂₈H₂₄N₆)Cd(SCN)₂]₂(CH₃OH)₂ (1) has been synthesized and characterized by IR, UV spectra, TG-DTA technique and single crystal X-ray diffraction analysis. The crystallographic data for compound 1: triclinic P1ˉ, a = 9.630(2) Å, b = 11.123(3) Å, c = 15.396(4) Å, α = 106.93(1)°, β = 91.60(1)°, γ = 99.99(1)°, V = 1,548.5(6) Å³, Z = 1, Dc = 1.512 mg/m³, F(000) = 716, R ₁ = 0.0332, wR ₂ = 0.0907. The molecule contains a symmetrical dinuclear unit in which two Cd(II) ions are double bridged by two di-μ-1,3-SCN⁻ anoins with a cadmium–cadmium separation of 6.48 Å. Each Cd(II) ion is seven-coordinated with six nitrogen atoms and a sulfur atom to form a monocapped trigonal prism coordination geometry. In addition, the molecule is further connected by multiform intermolecular C–H···π, π···π interactions and hydrogen bonds to form a three-dimensional supramolecular structure. Graphical Abstract  A hepta-coordinated Cd(II) complex which exhibits a distorted a monocapped trigonal prism coordination geometry has been achieved by using bisbidentate Schiff-base ligand and thiocyanate anion.      

Synthesis and Crystallographic Characterization of 1-((2-(2,4-Difluorophenyl)oxiran-2-yl)methyl)-1<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazole: A Crucial Intermediate for the Synthesis of Azole Antifungal Drugs

Abstract  

Preparation of oxirane 3 was accomplished in two steps. 1H-1,2,4-triazole was reacted with 2,4-difluoro-α-chloroacetophenone 1 in presence of K₂CO₃ in refluxing toluene to provide compound 2. Compound 2 was treated with trimethylsulfoxonium iodide (TMSI) in aq. NaOH and toluene to provide oxirane 3. Oxirane 3, previously isolated as an oil, was crystallized from (DCM/MeOH) and characterized by X-ray crystallography: triclinic, space group P − 1, a = 7.3225 (15), b = 7.5833 (15), c = 9.856 (2) Å, α = 91.908 (12), β = 100.824 (11), γ = 103.800 (11)°, V = 520.28 (18) ų, Z = 2. The molecule has a stepped conformation with nearly parallel triazole and phenyl rings. Lack of classical hydrogen-bond donors leads to packing dominated by weaker interactions, including C–H···N, C–H···F and F···F contacts.     

Synthesis and X-Ray Crystallographic Analysis of 2-(2, 4-Dimethyl Pyrrolyl) Benzothiazole

Abstract  

Synthesis of 2- (2, 4-dimethyl pyrrolyl) benzothiazole by chemical means and molecular structure by X-ray crystallographic techniques is reported. The compound crystallizes in the orthorhombic crystal system with space group Pbca and unit cell parameters: a = 12.161(9), b = 0.787(1), c = 16.792(2) Ǻ, V = 2202.8(4) Ǻ³ and Z = 8. The final reliability index is 0.073 for 7,959 observed reflections. The benzothiazole and pyrrole rings exist in planar conformations. The dihedral angle between the least-squares planes of both these moieties is 13.31°. There exists an isolated C4–H4···N1 intermolecular interaction, besides two C–H···S and C–H···N intermolecular interactions. The presence of C–H···S and C–H···N intramolecular interactions make the present molecule look like a virtual two-six-membered and three-five-membered ring structure.     

Crystal and Molecular Structure of 4-Aminobenzohydrazide

Abstract  

The molecule of 4-aminobenzohydrazide is essentially planar and geometric parameters conform to literature precedents. Supramolecular N–H···O and N–H···N interactions combine to link molecules of 4-aminobenzohydrazide into a three-dimensional network. Weaker N–H···N and N–H···π interactions consolidate the structure. The compound crystallizes in the monoclinic space group P2₁/n with a = 5.411(2) ?, b = 14.000(6) ?, c = 9.894(4) ?, β = 103.917(7)o, and Z = 4.     

The hydrogen bonding in 2-amino-3-cyano-4-(3-nitrophenyl)-4,6-dihydro-5H-pyrano[3,2-c]quinolin-5-one N,N-dimethylformamide solvate monohydrate

The crystal structure of 2-amino-3-cyano-4,6-dihydro-4-(3-nitrophenyl)-5H-pyrano[3,2-c]quinolin-5-one N,N-dimethylformamide solvate monohydrate is determined by room temperature X-ray diffraction. The title compound 1, C₂₂H₂₁N₅O₆, is triclinic, space group P-1, a=9.109(2) ?, b=11.340(2) ?, c=12.485(2) ?, α=70.02(1)°, β=69.36(1)°, γ=67.32(1)°, Z=2, V=1081.4(4) ?³. It is interesting that a bridge-like hydrogen bond O–H···O is formed between the title compound and solvent molecules of water with molecular ratio of 2:2 building a bi-layer framework. In addition, there are two other types of classical hydrogen bonds N–H···N and N–H···O in the crystal structure.Supplementary material Crystallographic data for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-275001. Copies of available material can be obtained, free of charge, on application to the Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, UK, (fax: +44-(0) 1223–336033 or e-mail: deposit@ccdc.cam.ac.uk).