Synthesis and Structural Characterization of a Nickel(II) Complex with Unsymmetrical NNO-Donor Schiff Base like Hydrazone Ligand

Abstract  

The nickel(II) complex Ni[C₅H₄N–C(CH₃)=N–N=C(O)–C₆H₅]₂ (1), containing the potentially tridentate Schiff base like hydrazone ligand (LH) which is the 1:1 condensation product of benzhydrazide and 2-acetylpyridine, was prepared and characterized by IR and UV–Vis spectra, thermal analysis and single crystal X-ray diffraction measurements. Structural investigation shows that the molecule prefers a monoclinic lattice, having space group Cc, a = 10.248(6), b = 19.692(11), c = 12.281(7) ?, β = 91.523(10)o, Z = 4. The central Ni atom is in N₄O₂ coordination sphere developed with the NNO donor sets of the two independently Schiff base like hydrazone ligands with the two Ni–N(pyridine) bonds being significantly longer than the two Ni–N(imino) bonds, 2.096(6), 2.105(6) versus 1.972(6), 2.008(6) ?. The two Ni(II) amide-O bond distances of the chelating ligands are 2.090(6) and 2.092(6) ? respectively.     

Structural Aspects and Spectroscopic Characterization of a Mn(II) Complex with Unsymmetrical NNO-Donor Hydrazone Ligand

Abstract  

The manganese(II) complex, Mn[C₅H₄N–C(CH₃)=N–N=C(O)–C₆H₅]₂ (1) containing N,N,O-donor hydrazone ligand is characterized by X-ray diffraction study. The ligand is the 1:1 condensation product of benzhydrazide and 2-acetylpyridine. The spectral, cyclic voltammetric and room-temperature magnetic moment data are used to establish structure and electronic structure of the compound. Structural investigation shows that 1 crystallizes to a monoclinic system, space group C2/c, a = 22.8367(13), b = 10.1523(6), c = 12.0736(7) Å, α = γ = 90°, β = 116.5930(10)°, and Z = 4. The central manganese atom is in an N₄O₂ coordination sphere constituted by the NNO donor sets of the two independently hydrazone ligands. The Mn–N1, Mn–N2 and Mn–O1 bond distances are 2.3255(15), 2.1854(13) and 2.1361(13) Å, respectively. The effective magnetic moment (μ_eff) value of 1 is found to be 5.92 B.M. at 300 K. Cyclic voltammetry shows Mn(III)/Mn(II) couple at 0.9 V and imine reductions at −0.68 and at −1.3 V.     

Synthesis and Crystal Structures of 4-Chloro-<Emphasis Type="Italic">N′</Emphasis>-(4-hydroxy-3-nitrobenzylidene)benzohydrazide monohydrate and 4-Chloro-<Emphasis Type="Italic">N′</Emphasis>-(4-hydroxy-3-methoxybenzylidene)benzohydrazide monohydrate

Abstract  

Two new hydrazone compounds, 4-chloro-N′-(4-hydroxy-3-nitrobenzylidene)benzohydrazide monohydrate (1) and 4-chloro-N′-(4-hydroxy-3-methoxybenzylidene)benzohydrazide monohydrate (2), were synthesized and characterized by physico-chemical methods and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group P2₁/c with unit cell parameters a = 23.257(3) ?, b = 4.829(1) ?, c = 12.763(2) ?, β = 96.017(2)°, V = 1425.5(5) ?³, Z = 4, R ₁ = 0.0525, and wR ₂ = 0.1120. Compound 2 crystallizes in the monoclinic space group P2₁/c with unit cell parameters a = 8.103(3) ?, b = 21.321(3) ?, c = 10.594(3) ?, β = 120.281(2)°, V = 1580.5(8) ?³, Z = 4, R ₁ = 0.0480, and wR ₂ = 0.1078. Both compounds contains a hydrazone molecule and a water molecule. The crystals of the compounds are stabilized by N–H···O, O–H···O, and O–H···N hydrogen bonds.     

Hydrogen Bonded Supramolecular Assembly in N6-Benzyladeninium Nitrate and N6-Benzyladeninium 3-Hydroxy Picolinate: A Synthetic Cytokinin

Abstract  

N ⁶-benzyladeninium nitrate, (1), C₁₂H₁₂N₅ ⁺ NO₃ ⁻ crystallizes in P2 ₁/c, with a = 15.0035(13), b = 5.3788(5), c = 16.8954(13) ?, β = 107.331(6)°, Z = 4 and N ⁶-benzyladeninium 3-hydroxy picolinate, (2), C₁₂H₁₂N₅ ⁺ C₆H₄NO₃ ⁻, crystallizes in P1, with a = 8.3017(4), b = 14.6170(7), c = 14.7909 (8) ?, α = 78.801 (4), β = 81.979 (4),γ = 88.849 (4)°, Z = 4. In both the salts, the cation exists as N(7)H tautomer with protonation at the N₃ atom. The dihedral angle of 76.64 (16)° for (1), 67.91(12)° for (cation A) and 68.27 (13)° for (cation B) in (2), between the adenine plane and phenyl ring plane, the distal orientation of the N6 substituent with respect to the imidazole ring and the free N1 position, make these benzyladeninium cations meet all the requirements necessary for cytokinin activity. The crystal structures are stabilized by N–H···N, N–H···O, C–H···O hydrogen bonds and C–H···π stacking interaction between symmetry related benzyladenine molecule.     

The Zolmitriptan-Pyridine (1:1) and Zolmitriptan-Propiophenone (3:2) Inclusion Complex

Abstract  

The crystal structures of zolmitriptan with pyridine (I) and propiophenone (II) solvates have been determined by single crystal X-ray diffraction studies. Compound (I) crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 8.5610(5) ?, b = 12.2709(7) ?, c = 19.6201(12) ?, V = 2061.1(2) ?³, and Z = 4, while compound (II) crystallizes in the monoclinic space group P2₁ with a = 15.085(1) ?, b = 19.656(12) ?, c = 21.0860(13) ?, β = 92.068(1)°, V = 6248(4) ?³ and Z = 4. The asymmetric unit of (I), C₁₆H₂₁N₃O₂·C₅H₅N, contains one zolmitriptan molecule and one pyridine solvate, while the asymmetric unit of (II), 3(C₁₆H₂₁N₃O₂)·2(C₉H₁₀O) comprises six zolmitriptan molecules and four propiophenone solvates. In both structures, the N–H···N hydrogen bonds, form an infinite helical chain and generate a C(11)-type motif in (I) and a D₂²(13)-type motif in (II). Both the complexes have layer structures, the layers being constructed from rings (cavity) of four zolmitriptan molecules, hydrogen bonded through N–H···N and N–H···O bonds, where the pyridine (I) and propiophenone (II) solvates are included in an R₄⁴(33) ring.     

NH?O and NH?N Hydrogen Bonded Networks in Imidazole-Based Phosphane Oxides: Structures of Tris(2-Isopropylimidazol-4(5)-yl)Phosphane Oxide, Bis(2-Isopropylimidazol-4(5)-yl)Phosphane Oxide and Diphenyl-2-Isopropylimidazol-4(5)-yl Phosphane Oxide

Abstract  

The three title compounds show extensive hydrogen bonding networks in the solid state. The structure of diphenyl-2-isopropylimidazol-4(5)yl phosphane oxide (3) is dominated by N–H⋯OP hydrogen bonds, whereas in bis(2-isopropylimidazol-4(5)-yl)phenyl- (2) and tris(2-isopropylimidazol-4(5)yl)phosphane oxide (1) both, N–H⋯N and N–H⋯OP hydrogen bonds determine the solid-state structures. Compound 1 crystallises in the monoclinic space group Cc with cell parameters a = 19.5447(6) ?, b = 10.45764(16) ?, c = 10.8549(3) ? and β = 121.418(4)°; 2 in the orthorhombic space group Pna2₁, with a = 11.5997(3) ?, b = 9.5836(2) ?, c = 16.1860(4) ? and 3 in the orthorhombic space group Pca2₁, with a = 10.8430(2) ?, b = 10.9277(2) ? and c = 27.7088(6) ?.     

Synthesis,Crystal Structures,and Antibacterial Activity of Two Hydrazone Derivatives 3-Methoxy-<Emphasis Type="Italic">N</Emphasis>′-(3,5-Dibromo-2-Hydroxybenzylidene)Benzohydrazide Methanol Solvate and 3-Methoxy-<Emphasis Type="Italic">N</Emphasis>′-(2,4-Diclorobenzylidene)Benzohydrazide

Abstract  

Two new hydrazone compounds with the formulae C₁₅H₁₂Br₂N₂O₃·CH₃OH (1) and C₁₅H₁₂Cl₂N₂O₂ (2), were prepared and characterized by elemental analysis, IR spectra and single-crystal X-ray determination. Compound (1) crystallizes in the triclinic space group P-1 with unit cell dimensions a = 7.654(1) ?, b = 13.801(2) ?, c = 16.904(2) ?, α = 90.772(2)^o, β = 101.721(2)^o, γ = 95.891(2)^o, V = 1738.1(4) Ǻ³, Z = 4, R ₁ = 0.0495 and wR ₂ = 0.1161. Compound (2) crystallizes in the triclinic space group P-1 with unit cell dimensions a = 8.296(1) ?, b = 12.987(2) ?, c = 14.121(2) ?, α = 88.922(2)^o, β = 87.960(2)^o, γ = 84.130(2)^o, V = 1512.3(4) Ǻ³, Z = 4, R ₁ = 0.0526 and wR ₂ = 0.1220. The single crystal structure analysis indicates that compound (1) consists of two nearly coplanar hydrazone molecules and two methanol molecules which link to the hydrazone molecules through O–H···O hydrogen bonds, while compound (2) consists of two independent distorted hydrazone molecules. In the crystal structure of (1), adjacent two hydrazone molecules are linked with methanol molecules through intermolecular hydrogen bonds of O–H···O and N–H···O, forming a dimer. In the crystal structure of (2), molecules are linked through intermolecular N–H···O hydrogen bonds, forming chains running along the a axis.     

Syntheses,Characterization and Crystal Structures of <Emphasis Type="Italic">N′</Emphasis>-(5-Chloro-2-Hydroxybenzylidene)-4-Dimethylaminobenzohydrazide and <Emphasis Type="Italic">N′</Emphasis>-(2,4-Dichlorobenzylidene)-4-Dimethylaminobenzohydrazide

Abstract  

The hydrazone compounds, N′-(5-chloro-2-hydroxybenzylidene)-4-dimethylaminobenzohydrazide (1) and N′-(2,4-dichlorobenzylidene)-4-dimethylaminobenzohydrazide (2), have been synthesized by the condensation reaction of equimolar quantities of 4-dimethylaminobenzohydrazide with 5-chlorosalicylaldehyde and 2,4-dichlorobenzaldehyde, respectively, in methanol. The compounds were characterized by elemental analysis, IR, ¹HNMR spectra, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 35.014(3) ?, b = 10.407(2) ?, c = 18.505(2) ?, β = 112.046(2)°, V = 6250.0(15) Ǻ³, Z = 16, R ₁ = 0.0624, and wR ₂ = 0.1187. Compound 2 crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.625(2) ?, b = 12.688(3) ?, c = 13.005(2) ?, α = 101.271(2)°, β = 112.945(1)°, γ = 104.966(2)°, V = 1747.6(6) Ǻ³, Z = 2, R ₁ = 0.0523, and wR ₂ = 0.1138. In the asymmetric unit of each compound, there exists two hydrazone molecules linking together by an N–H⋯O hydrogen bond. Furthermore, compound (2) contains one methanol molecule and one water molecule of crystallization.     

Self-Assembly of a New 1D Coordination Polymer Built of [Nb<Subscript>6</Subscript>Cl<Subscript>12</Subscript>(CN)<Subscript>6</Subscript>]<Superscript>4−</Superscript> and Mn(III) Complexes

Abstract  

A new 1D coordination polymer [Me₄N]₃{[Mn(L)][Nb₆Cl₁₂(CN)₆]}·3MeCN·H₂O (1) (L = acacen ²⁻ = N,N′-bis(acetylacetone)-1,2-ethylenediimine) was synthesized from reaction between [Me₄N]₄[Nb₆Cl₁₂(CN)₆] and [Mn(L)]Cl in acetonitrile. The crystal structure of 1 was determined from single-crystal X-ray diffraction analysis. Compound 1 crystallizes in the tetragonal system, space group I4₁/a (No. 88), a = 30.585(4), c = 27.348(6) ?, V = 25582(7) ?³, Z = 16. Its 1D framework consists of chains formed of metal clusters and Mn(L) complexes linked to each other by Nb–C≡N–Mn–N≡C–Nb linkages. The chains extend along the a and b crystallographic axes and are related to each other by 4₁ screw axis. The chains are held together by [Me₄N]⁺ cations and solvent molecules located in channels running between the chains. 1 and the previously reported 1D coordination polymer [Me₄N]₃{[Mn(5-MeO-salen)][Nb₆Cl₁₂(CN)₆]} (3) differ from each other in terms of their synthesis and their structural characteristics.     

Structure of a New Bioactive Agent Containing Combined Antibacterial and Antifungal Pharmacophore Sites: 4-{[(<Emphasis Type="Italic">E</Emphasis>)-(5-Bromo-2-hydroxyphenyl)methylidene]amino}-<Emphasis Type="Italic">N</Emphasis>-(5-methyl-1,2-oxazol-3-yl)benzenesulfonamide

Abstract  

The title compound (3), C₁₇H₁₄BrN₃O₄S, is a Schiff base compound of 5-bromosalicylaldehyde (1) and sulfamethoxazole (2). The structure of (3) was determined by spectral (IR, ¹H and ¹³C NMR), elemental analyses and X-ray diffraction data. Compound (3) crystallizes in the monoclinic space group C2/c, with a = 31.936(3), b = 6.2571(5), c = 16.903(1) ?, β = 94.867(8), V = 3365.5(5) ?³, Z = 8. In the molecule of compound (3), the molecule is bent at the S atom with a C–SO₂–NH–C torsion angle of −86.3(3)°. Pairs of molecules, related by inversion centres, form intermolecular N–H···N hydrogen bonds to produce a dimer. An intramolecular phenolic O–H···N hydrogen bond is also formed. Intermolecular hydrogen bonding and π–π stacking hold the molecules together. The average distance between stacked benzene ring planes is 3.625(2) ?.     

Synthesis,Structural and Thermal Studies of a New Nickel Complex Containing 2-Aminopyrimidine and Thiocyanate Mixed Ligands with a Three-Dimensional Network Structure

Abstract  

A new nickel(II) complex formulated as, trans-[Ni(amp)₂(SCN)₂(H₂O)₂]·2H₂O (1), (amp = 2-aminopyrimidine) has been synthesized and characterized by elemental analysis, IR spectroscopy, its molecular and crystal structures were determined by X-ray crystal structure analysis and its thermal stability by TGA/DTA methods. 1 is a neutral complex and the central atom sits on an inversion center and is coordinated by two endocyclic nitrogen atoms of two 2-aminopyrimidine heterocycles, two oxygen atoms of two water molecules and two nitrogen atoms of SCN⁻ ions. 2-aminopyrimidine molecules, thiocyanate ions and water molecules are in trans position. Thermal methods confirm two co-crystallized water molecules in 1. π–π stacking interactions and extensive O–H···O, O–H···N, O–H···S and N–H···N hydrogen bonds contribute to the formation of a three-dimensional supramolecular structure. Crystal data for complex at 120 K: triclinic, space group P-1, a = 7.2026(14), b = 7.8332(15), c = 9.0270(17) ?, α = 67.694(3), β = 72.732(4), γ = 77.012(4), Z = 1, R ₁ = 0.0323.     

Synthesis and Structural Characterization of <Emphasis Type="Italic">N</Emphasis>-(2-Pyridylmethyl)-3-Methoxysalicylaldiminato Copper(II) Chloride

Abstract  The copper(II) complex [Cu(C₅H₄NCH₂−N=CH–C₆H₃OCH₃–O)Cl], (1) containing a new tridentate Schiff base ligand (LH), which is the 1:1 condensation product of 2-(aminomethyl)pyridine and o-vaniline, has been synthesised and characterized by IR and UV–Vis spectra. Structural investigation shows that 1 crystallizes to a monoclinic system, having space group P2(1)/c, a = 6.9634(7), b = 18.1209(19), c = 10.3448(11) ?, α = 90°, β = 103.97(2)°, γ = 90° and Z = 4. The coordination geometry around the copper atom is slightly distorted square planar, formed by the N₂O donor set of the Schiff base and one Cl atom. The Cu–N(1), Cu–N(2), Cu–O(1) and Cu–Cl bond distances are 2.0114(14), 1.9414(14), 1.9147(12) and 2.2520(5) ?, respectively. Index Abstract  The copper(II) complex [Cu(C₅H₄NCH₂−N=CH–C₆H₃OCH₃–O)Cl], (1) containing a tridentate Schiff base ligand (LH), synthesised and characterized by IR and UV–Vis spectra. The central copper ion possesses a distorted square-planar geometry.      

Molecular Association of Almotriptan with Oxalate and Terephthalate Anions

Abstract  

Crystal structures of anti-migraine drug almotriptan were crystallized with oxalic acid (I) and with terephthalic acid (II) and their crystal structures and molecular associations were determined using X-ray diffraction methods. Crystals of both (I) and (II) are monoclinic, space group P2₁/c, with a = 5.6270(4) ?, b = 27.6419(19) ?, c = 13.6228(9) ?, β = 93.057(1)°, V = 2115.9(3) ?³, Z = 4 (I) and a = 13.3756(15) ?, b = 15.6065(17) ?, c = 10.7238(12) ?, β = 98.017(2)°, V = 2216.7(4) ?³, Z = 4 (II). In almotriptan oxalate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium semioxalate}, C₁₇H₂₆N₃O₂S⁺, C₂HO₄ ⁻, (I) and in almotriptan hemi terephthalate hydrate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium hemi terephthalate monohydrate}, C₁₇H₂₆N₃O₂S⁺, 0.5(C₈H₄O₄ ²⁻), H₂O, (II), both the almotriptan cations form a trimer with the corresponding anions via N–H···O hydrogen bonds. In (I), the oxalate salt is monoprotonated and in (II), the terephthalic acid is located across the inversion centre and exists as doubly protonated anion. In (I), the cation and anion are interlinked by the N–H···O and O–H···O hydrogen bonds into continuous two-dimensional layers generate an R₆⁶(34) hydrogen-bonded motif tetramers running parallel to the (0 0 1) plane. In (II), the cation and water form a centrosymmetric tetramer of R₄⁴(22) hydrogen-bonded motif via N–H···O and O–H···O hydrogen bonds and further cross-linked by centrosymmetric anions to form an infinite three-dimensional supramolecular hydrogen-bonded networks.     

Cross Coupling of Substituted Anilines with Quinoline: Synthesis and Structural Characterization of HN(py)quin,PhN(py)quin,MesN(py)quin,and [PhN(py)(H-quin)]BF<Subscript>4</Subscript>

Abstract  

The molecular structure of (2,6-ⁱPr₂C₆H₃)N(quin)₂ (1) and both the methanol and toluene solvates of its copper complex [Cu{(2,6-ⁱPr₂C₆H₃)N(quin)₂}₂]BF₄, 2·MeOH and 2.2(C₆H₅Me), respectively, have been determined. The quinolyl rings in 1 adopt anti-syn (C_Ar–N–C–N_quin) conformation as a result of π–π stacking. The cation in 2·MeOH crystallizes on a C₂ axis, while the cation in 2·2(C₆H₅Me) is crystallographically independent. As a result of intramolecular π–π stacking there are significant changes within the coordination geometry about the copper centers between the two solvates, suggesting that the coordination around copper is supple. Crystal data: 1 group P2₁/c, a = 8.614(1), b = 16.137(3), c = 17.601(4) ?, β = 93.32(3)°, V = 2,442.5(9) ?³, Z = 4, R = 0.0544, wR ₂ = 0.1340. 2·MeOH group P3₂21, a = 13.254(1), b = 13.254(1), c = 27.214(5) ?, V = 4,140(1) ?³, Z = 3, R = 0.0392, wR ₂ = 0.0917. 2.2(C₆H₅Me) group P1, a = 11.677(2), b = 16.261(3), c = 17.077(3) ?, α = 93.63(3), β = 97.30(3), γ = 96.26(3)°, V = 3,187(1) ?³, Z = 4, R = 0.0526, wR ₂ = 0.1221.     

Syntheses, Characterization and Crystal Structures of Two Isostructural Hydrazone Compounds N′-(3-Bromo-5-chloro-2-hydroxybenzylidene)-4-chlorobenzohydrazide Methanol Solvate and N′-(3,5-Dichloro-2-hydroxybenzylidene)-4-chlorobenzohydrazide Methanol Solvate

Abstract  

Reactions of 4-chlorobenzohydrazide with 3-bromo-5-chloro-2-hydroxybenzaldehyde and 3,5-dichloro-2-hydroxybenzaldehyde, respectively, afforded two isostructural hydrazone compounds, C₁₄H₉BrCl₂N₂O₂·CH₃OH (1) and C₁₄H₉Cl₃N₂O₂·CH₃OH (2). Both compounds were structurally characterized by X-ray determination. Compound 1 crystallizes in the triclinic space group P − 1 with unit cell dimensions a = 7.462(1) ?, b = 9.281(2) ?, c = 12.626(1) ?, α = 98.451(2)°, β = 98.630(2)°, γ = 100.025(2)°, V = 837.8(2) ?³, Z = 2, R ₁ = 0.0394 and wR ₂ = 0.0967. Compound 2 crystallizes in the monoclinic space group P2₁/n with unit cell dimensions a = 7.485(1) ?, b = 13.389(2) ?, c = 16.693(2) ?, β = 99.754(2)°, V = 1648.7(4) ?³, Z = 4, R ₁ = 0.0375 and wR ₂ = 0.0900. X-ray structural determination revealed that each compound consists of a hydrazone molecule and a methanol molecule of crystallization. In the crystal structures of both compounds, the adjacent molecules are linked by methanol molecules through N–H···O and O–H···O hydrogen bonds, forming dimers.     

Synthesis, Characterization, and Crystal Structures of 3-bromo-N′-(2-methoxybenzylidene)benzohydrazide and N′-(2-methoxybenzylidene)-3,4-methylenedioxybenzohydrazide

Abstract  

Two new hydrazone compounds, 3-bromo-N′-(2-methoxybenzylidene)benzohydrazide (1) and N′-(2-methoxybenzylidene)-3,4-methylenedioxybenzohydrazide (2), have been synthesized and characterized by elemental analysis, IR, and single crystal X-ray diffractions. Compound (1) crystallizes in the triclinic space group P1 with unit cell dimensions a = 8.4088(5) ?, b = 8.5398(5) ?, c = 10.6572(6) ?, α = 90.356(3)°, β = 102.868(3)°, γ = 97.987(3)°, V = 738.28(7) Ǻ³, Z = 2, R ₁ = 0.0406, and wR ₂ = 0.0804. Compound (2) crystallizes in the tetragonal space group P4₁ with unit cell dimensions a = b = 9.792(4) ?, c = 15.788(6) ?, V = 1513.8(10) Ǻ³, Z = 4, R ₁ = 0.0415, and wR ₂ = 0.0818. The molecules of both compounds display E configurations with respect to the C=N double bonds. In the crystal structure of (1), molecules are linked through N–H···O hydrogen bonds, forming chains running along the b axis. In the crystal structure of (2), molecules are linked through N–H···O hydrogen bonds, forming chains running along the c axis.     

Structures of two N-methylated tricyclic quinolones with antimalarial activity

The crystal structures of two N-methylated tricyclic quinolones were determined. 3-amino-6-methoxy-9-methyl-(1H)pyrazolo[3,4-b]-4-quinolone hydrate, C₁₂H₁₂N₄O₂ · H₂O (1) crystallizes in P-1 with a=11.5078(18) ?, b=13.0614(19) ?, c=9.0860(15) ?, α=106.229(4)°, β=108.378(3)°, γ=71.118(3)° and Z=4, while 2,4-diamino-10-methyl-9-methoxypyrimido[4,5-b]-5-quinolone, C₁₃H₁₃N₅O₂ (2) crystallizes in P2₁/n with a=10.6643(17) ?, b=10.1114(17) ?, c=11.3185(18) ?, β=99.351(4)° and Z=4. Both molecules are essentially planar, including the exocyclic groups. 1 and 2 have moderate antimalarial activity which seems to be related to the formation of intramolecular N – H · · · O=C hydrogen bonds; 1 does not form these bonds and has approximately twice the activity of 2. In both crystal structures there are extensive networks of N–H · · · O and N–H · · · N hydrogen bonds, and in 1 the water molecules of solvation form N–H · · · Ow, Ow–H · · · O=C and Ow–H · · · Ow bonds.     

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.     

1-Phenyldiazenyl-8-Phenylhydrazononaphthalene-7(8H)-One-2-ol: Co-Existence of Azo-Hydroxy and Hydrazo-Keto Forms

Abstract  

The compound crystallizes in the triclinic P[`1] P\bar{1} space group and unit cell dimensions of a = 8.158 ?, b = 12.490 ?, c = 17.129 ?; α = 93.24°, β = 94.72°, γ = 97.61° and Z = 4. The structure was solved by direct methods and refined to an R1 value of 0.0890 on 2,278 observed reflections. There are two molecules in the asymmetric residue unit of the compound. In the title compound C₂₂H₁₆N₄O₂, two diazene groups at C1 and C8 and two hydroxy groups at C2 and C7 bring into play a unique azo-hydrazo equilibrium in which azo-hydroxy and hydrazo-keto forms co-exist in the molecule. The hydrazone H atom and the keto O atom are linked by an intramolecular N–H···O hydrogen bond on the other hand the hydroxy H atom and the azo N atom are linked by two intramolecular O–H···N hydrogen bonds.     

Synthesis and Structural Characterization of [2-(2-1H-Imidazoly)-1H-imidazolium nitrate] and [2-(2-1H-Imidazoly)-2H-imidazolium phthalyl glycinate] Based on the 2,2′-bi-1H-Imidazole Molecule

Abstract  

Two new compounds (H₃biim)(NO₃)(1) and (H₄biim)(phthgly)₂ (2) (H₂biim=biimidazole; Hphthgly=N-phthaloylglycine) have been synthesized and characterized by luminescence and single crystal X-ray diffraction study. Compound 1 crystallizes in the monoclinic space group C2/c, where a = 14.8078(15), b = 5.9233(6), c = 20.028(2) ?, β = 92.7910(10)°, V = 1754.6(3) ?³ and Z = 8. Compound 2 crystallizes in the monoclinic space group P2(1)/n, where a = 15.3775(14), b = 5.3200(6), c = 6.4689(18)?, β = 115.418(2)° V = 1216.9(2)?³ and Z = 4. In 1, the N–H groups of H₃biim⁺ and the oxygen atoms of NO₃ ⁻ are linked by hydrogen bonds leading to H₃biim⁺(N,N)–R₂²(10) and N–H···O interactions forming infinite 1D helical chains along the b-axis. Compound 2 consists of a planar diprotonated biimidazole moiety and two phthgly anions which connect to the dication by hydrogen bonds phthgly⁻(O,O)–R₂²(9).