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.     

Crystal and Molecular Structure of the 1:2 Salt Formed Between 1,2-(4-Pyridyl)Ethane and 2-(4-Hydroxyphenylazo)Benzoic Acid

Abstract  Proton transfer occurred during co-crystallization of 1,2-(4-pyridyl)ethane with 2-(4-hydroxyphenylazo)benzoic acid to yield a salt comprising a 1:2 ratio of 1,2-bis(4-pyridinium)ethane dications and 2-(4-hydroxyphenylazo)benzoate anions. Centrosymmetrically related anions associate by charge-assisted O–H···O hydrogen bonds to form 24-membered {···OC₃N₂C₄OH}₂ synthons. These are connected into a supramolecular polymer via charge-assisted N–H···O hydrogen bonds involving the 1,2-bis(4-pyridinium)ethane dications. The compound crystallizes in the triclinic space group P−1 with a = 8.517(4) ?, b = 9.110(5) ?, c = 10.477(5) ?, α = 96.850(13)°, β = 94.446(12)°, γ = 104.946(10)° and Z = 1 {two anions and a dication}. Index Abstract  Supramolecular chains mediated by charge-assisted O–H···O and N–H···O hydrogen bonding are found in the salt containing a 1:2 ratio of 1,2-bis(4-pyridinium)ethane dications and 2-(4-hydroxyphenylazo)benzoate anions.      

Structures of two N-{2-([(5-amino-1,3,4-thiadiazol-2-yl)difluoromethyl]-4-halophenyl}acetamides

Abstract  

The compounds, N-{2-[(5-amino-1,3,4-thiadiazol-2-yl)difluoromethyl]-4-chlorophenyl}acetamide (1: X = Cl) and N-{2([(5-amino-1,3,4-thiadiazol-2-yl)difluoromethyl]-4-bromo-phenyl}acetamide (1: X = Br), are isostructural. The molecules are near ‘‘V’’ shaped with the angles between the two aromatic planes ca. 84° in each case. The various intermolecular interactions, namely N–H···O, N–H···N, N–H···F, and C–H···N hydrogen bonds and C–H···π, C–Cl···π and C–O···π interactions, generate 3-D arrays. Compound (1: X = Cl) crystallizes in the monoclinic space group P21/c with a = 16.9032(7) ?, 10.2193(4) ?, c = 7.5227(4) ?, β = 100.179(3)° and Z = 4. Compound (1: X = Br) crystallizes in the monoclinic space group P21/c with a = 17.2119(4) ?, 10.2167(2) ?, c = 7.5677(2) ?, β = 100.326(2)° and Z = 4.     

Spectral and X-ray Diffraction Studies of <Emphasis Type="Italic">N</Emphasis>-(2-Nitrophenyl)-5-Phenyl-1,3,4-Oxadiazole-2-Amine

Abstract  

Thiosemicarbazides and their derivatives are well known for their use in biological activity and many applications in pharmaceutical and industrial fields. The cyclization of 1-benzoyl-4-(2-nitrophenyl)-3-thiosemicarbazide (BNPTSC) in dimethylformamide (DMF) medium furnished N-(2-nitrophenyl)-5-phenyl-1,3,4-oxadiazole-2-amine (NPPOA). The chemical structure of the above substituted 1,3,4-oxadiazole has been assigned by IR, mass and X-ray diffraction studies. The XRD studies reveal the presence of four types of hydrogen bonds (N–H···O, N–H···N, C–H···O, C–H···N) in the crystal packing. The crystal system was found to be orthorhombic with a space group Pca2(1) and the unit cell dimensions are: a = 26.873(3) ?, b = 6.0827(7) ?, c = 7.8502(10) ?, α = 90°, β = 90°, γ = 90° and Z = 4.     

Synthesis and Crystal Structure of a Fe(III) Complex with an Isonicotinyl Hydrazone Ligand, [Fe(N-Isonicotinamidosalicylaldimine)Cl<Subscript>2</Subscript>]

Abstract  

A new complex [Fe(N-isonicotinamidosalicylaldimine)Cl₂] has been synthesized by template reaction at room temperature and structurally characterized by X-ray single-crystal analysis. The complex crystallizes in triclinic crystal system, Pī space group, a = 7.273(6) ?, b = 10.015(8) ?, c = 10.479(8) ?, α = 71.067(10)°, β = 89.964(11)°, γ = 75.528(10)°, V = 696.4(9) ?³ and Z = 2. The coordination geometry around the Fe(III) ion is a distorted trigonal bipyramid with a O₂N₁Cl₂ donor set. In the crystal structure, N–H···Cl, C–H···O and C–H···Cl hydrogen bonds and π···π stacking interactions involving aromatic and unclosed π-systems link the molecules to form supramolecular double layers.     

Crystal Structure,Conformation and Vibrational Analysis of a Mannich Base: 2-[(phenylamino) methyl]-isoindole-1,3-dione

Abstract  

The crystal structure of 2-[(phenylamino) methyl]-isoindole-1,3-dione, C₁₅H₁₂N₂O₂, crystallizes in the triclinic space group Pī with cell parameters of a = 7.1176 (2) ?, b = 8.5533 (3) ?, c = 10.9163 (4) ?, α = 95.937 (2)°, β = 102.975 (2)°, γ = 108.474 (2)°, V = 603.18 (4) ?³ and Z = 2. This indole derivative is a Mannich base in which a methyl group bridges the molecules of phthalimide and aniline molecules. The dihedral angle between the phthalimide and aniline is 75.47 (3)°. The molecules of the title compound forms a centrosymmetric hydrogen-bonded dimer through a pair of N–H···O hydrogen bonds. C–H···π and an extensive π···π interactions, in addition, stabilize the molecular structure. The compound presented here is V-shaped, the angle at the methyl bridge [N–C–N] being 115.04 (12)°. Present study reports the conformation and hydrogen bonding interactions which play an important role in biological functions. Vibration analysis complement the structure analysed.     

Inter- and Intra-Molecular Hydrogen Bonding in Bis(2-amino-5-fluoro-3-methylphenyl)disulfide

Abstract  Bis(2-amino-5-fluoro-3-methylphenyl)disulfide was obtained by oxidation of 2-amino-5-fluoro-3-methylbenzenethiol and was characterized by elemental analysis, IR and ¹H-NMR spectroscopy. The X-ray structure was determined. Crystal data: C₁₄H₁₄N₂F₂S₂: Monoclinic, P2₁ /n, a = 11.8268(3), b = 9.5770(3), c = 12.3977(3) ?, β = 98.079(2)°, V = 1390.29(7) ?, Z = 4. The supramolecular structure arises because the NH₂ groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds. Index Abstract  Inter- and Intra-Molecular Hydrogen Bonding in Bis(2-amino-5-fluoro-3-methylphenyl)disulfide J. E. Drake¹, M. B. Hursthouse², M. E. Light², R. Maheshwari³, K.G. Ojha³, R. Ratnani^3* Bis(2-amino-5-fluoro-3-methylphenyl)disulfide is linked into a three-dimensional frame work by a combination of intermolecular N–H···F and N–H···N and intramolecular N–H···S hydrogen bonds. The supramolecular structure arises because the NH₂ groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds.      

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.      

Synthesis,Characterization and Crystal Structure of (<Emphasis Type="Italic">S</Emphasis>)-2-(2-Hydroxynaphthalen-6-yl)-<Emphasis Type="Italic">N</Emphasis>-((pyridin-4-yl)methyl) Propanamide

Abstract  

The synthesis, characterization and crystal structure of the title compound, (S)-2-(2-hydroxynaphthalen-6-yl)-N-((pyridin-4-yl)methyl) propanamide, is described. The salt is enantiomerically pure and crystallize in the orthorhombic P2₁2₁2₁ chiral space group with a = 7.9174(13) ?, b = 11.1583(18) ?, c = 11.2600(18) ?. Each molecule is linked to four neighboring molecules through the O–H···O and N–H···N hydrogen bonds into a supramolecular helical chain. The O–H···O and N–H···N hydrogen bonds lead to 24-membered open rings. Chains are further connected into layers via extensive interchain H···O and H···C short contacts.     

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) ?.     

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.     

One Porous Supramolecular Complex Assembled from Ionic and Neutral Hydrogen-bonds of N–H···O and C–H···O

Abstract  

The imidazolyl derived complex N,N′-butylenebis(imidazole):(oxalic acid)_0.5 was prepared and structurally characterized by X-ray crystallography. The title compound crystallizes in the triclinic, space group P-1, with a = 4.4373(9) ?, b = 12.882(3) ?, c = 15.319(3) ?, α = 99.91(3)°, β = 94.53(3)°, γ = 98.72(3)°, V = 847.7(3) ?³, Z = 2. Two N,N′-butylenebis(imidazole) and two oxalic acid molecules form an annulus via intermolecular hydrogen bonds, with internal dimensions of about 7.1 × 11.1 ?. Neighboring annuluses were connected by N–H···O and C–H···O interactions to form 1D double chain structure. Adjacent double chains stacked just above each other along the a-axis direction, this arrangement of the double chains leads the extended supramolecular architecture to show a three-dimensional porous network.     

Synthesis and Crystal Structure of Heptyl 3-(3,4-dihydroxyphenyl)-2-propenoate

Abstract  The title compound, C₁₆H₂₂O₄, synthesized by modified Knoevenagel condensation of protocatechualdehyde with monoheptyl-malonate and recrystallized from benzene, was confirmed by single-crystal X-ray diffraction (CCDC 272827). The compound crystallizes in triclinic space group Pī with cell parameters a = 5.296(3) ?, b = 10.711(13) ?, c = 13.870(4) ?, α = 98.84(7)°, β = 90.97(4)°, γ = 96.77(7)° and Z = 2. The structure is the E isomer and its packing is stabilized by intermolecular O–H···O and C–H···O hydrogen bonds. Index Abstract  The title compound, C₁₆H₂₂O₄, synthesized by modified Knoevenagel condensation, was confirmed by single-crystal X-ray diffraction showing its structure is in E isomer and its packing is stabilized by hydrogen bonds.      

Synthesis,Characterization, Crystal and Molecular Structure Analysis of 2,6-Dimethyl-3-acetyl-5-carbomethoxy-4-(3-nitrophenyl)-1,4-dihydropyridine

Abstract  A novel unsymmetrical dihydropyridine, possessing carboxymethyl and carbomethoxy groups at C(3) and C(5), respectively, has been produced using a modified Hantzsch synthesis, under solvent free conditions, in a domestic microwave oven. The product obtained was characterized by spectroscopic techniques and finally confirmed by X-ray diffraction studies. The title compound C₁₇H₁₈N₂O₅ crystallizes in the monoclinic system in the space group P2₁/c with cell parameters a = 12.860(2) ?, b = 7.4950(6) ?, c = 16.734(3) ?, β = 94.436(3)°, Z = 4 and V = 1608.1(4) ?³. The 1,4-dihydropyridine ring in the structure is in a flattened boat conformation. The molecule possesses a chiral center at C4. The 3-nitrophenyl ring is nearly orthogonal to the 1,4-dihydropyridine ring. The carbonyl groups at C3 and C5 are oriented in −antiperiplanar and +synperiplanar conformations, respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O and C–H···O. Index Abstract  A novel unsymmetrical dihydropyridine, possessing carboxymethyl and carbomethoxy groups at C(3) and C(5) respectively, has been produced using a modified Hantzsch synthesis, under solvent free conditions, in a domestic microwave oven. The product obtained was characterized by spectroscipic techniques and finally confirmed by X-ray diffraction studies. The title compound C₁₇H₁₈N₂O₅ crystallizes in the monoclinic system in the space group P2_1/c with cell parameters a  =  12.860(2) ?, b  =  7.4950(6) ?, c  =  16.734(3) ?, β = 94.436(3)°, Z = 4 and V = 1608.1(4) ?³. The 1,4-dihydropyridine ring in the structure is in a flattened boat conformation. The molecule possesses a chiral center at C(4). The 3-nitrophenyl ring is nearly orthogonal to the 1,4-dihydropyridine ring. The carbonyl groups at C(3) and C(5) are oriented in −antiperiplanar and +synperiplanar conformations respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O and C–H···O.

Synthesis,Crystal Structure and ab Initio Studies of 5-Phenylamino-3-phenylimino-3H[1, 2]dithiole-4-carboxylic acid ethyl ester

Abstract  

5-Phenylamino-3-phenylimino-3H[1, 2]dithiole-4-carboxylic acid ethyl ester, C₁₈H₁₆N₂O₂S₂, (I), has been synthesized and the structure has been solved by X–ray diffraction. The crystals are triclinic, space group P[`1] P\bar{1} , with a = 5.7127(2) ?, b = 12.1757(5) ?, c = 14.0734(5) ?, α = 112.1217(16)°, β = 97.786(2)°, γ = 100.694(2)°, Mr = 356.45, V = 868.11(6) ?³, Z = 2 and R = 0.0373. In the title compound there is an intramolecular N–H···O hydrogen bond. The crystal structure is stabilized only by weak C–H···π and π···π interactions as well as by van der Waals forces. The geometry of the isolated molecule was optimized by ab initio quantum mechanical calculations, employing both molecular orbital Hartree-Fock (HF) and density functional theory (DFT) methods. In the DFT calculation the minimum energy was achieved for a conformation very similar to that of the solid-state molecule.     

Crystal and Molecular Structure Studies of 1′-Benzyl-8-(4-fluorobenzyl)-8-azaspiro[bicyclo-[3.2.1]octane-3,4′-imidazolodine]-2′,5′-dione

Abstract  

The title compound, C₂₃H₂₃FN₃O₂ has been synthesized and the structure was investigated by X-ray diffraction studies. The compound crystallizes in the triclinic crystal class in the space group P[`1]P\overline{1} with cell parameters a = 9.345(2) ?, b = 10.940(3) ?, c = 11.986(4) ?, α = 72.349(6)°, β = 68.106(18)°, γ = 66.867(5)°, Z = 2 and V = 1027.8(5) ?³. The hydantoin ring adopts a planar conformation and is affected by the π conjugation. The pyrrolidine and piperidine rings in the bicyclo octane moiety adopt envelope and chair conformations respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O, C–H···O and C–H···N. One of the oxygen atoms attached to the hydantoin ring simultaneously accepts two hydrogen bonds to form a three centered hydrogen bonding pattern.     

Spectroscopic Studies and Crystal Structure of 1-[(2,5-dioxopyrrolidin-1-yl)(phenyl) methyl] Thiourea

Abstract  A new mannich base 1-[(2,5-dioxopyrrolidin-1-yl)(phenyl)methyl] thiourea formed by the direct condensation of thiourea, succinimide and benzaldehyde has been synthesized. The structure of this mannich base has been elucidated on the basis of micro elemental analysis, IR, ¹H NMR, ¹³C NMR, Mass and UV–Visible Techniques. The crystal structure of the title compound C₁₂ H₁₃ N₃ O₂ S was determined. It crystallizes in the monoclinic system, space group P2₁/c with a = 10.8234 (7) ?, b = 6.0355 (5) ?, c = 19.3692 (14) ?, β = 100.540(3)°, Z = 4 and V = 1243.94 (16) ?³. The structure was solved by the full-matrix least squares on F ² and had a refined R value of 0.0465 for 1,964 observed reflections. The crystal structure is stabilized by strong intramolecular C–H···O, C–H···S interactions and inter molecular N–H···O and S···S interactions. Graphical Abstract  This paper describes the spectroscopic and crystallographic studies of the title compound which is essential in ascertaining the structure of this new compound.      

Crystal and Molecular Structures of 2-Amino-4-Nitrobenzoic Acid and Its Cocrystals with 2,2′-Bipyridine (2/1) and Bis(pyridin-2-yl)ketone (1/1)

Abstract  

The eight-membered {···HOC=O}₂ synthon featured in the crystal structure of 2-amino-4-nitrobenzoic acid (1) is replaced by carboxylic acid···N-pyridine hydrogen bonds in its cocrystals with 2,2′-bipyridine (2/1; 2) and bis(pyridin-2-yl)ketone (1/1; 3) indicating the robust nature of the latter synthon. Disruption of the three-dimensional architecture based on O–H···O and N–H···O(nitro) hydrogen bonds in (1) is evident in the cocrystals which form supramolecular tubes (2) and chains (3) based on O–H···N and N–H···O hydrogen bonding. Compound (1) crystallizes in the monoclinic space group P2₁/n with a = 3.6291(1) ?, b = 7.7339(3) ?, c = 26.561(1) ?, β = 91.385(2)°, and Z = 4. Compound (2) crystallizes in the monoclinic space group C2/c with a = 27.562(3) ?, b = 6.8300(6) ?, c = 12.923(1) ?, β = 110.593(5)°, and Z = 4. Compound (3) crystallizes in the monoclinic space group P2₁/c with a = 3.795(3) ?, b = 12.024(8) ?, c = 35.65(2) ?, β = 92.131(6)°, and Z = 4 (determined from synchrotron data).     

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.     

Synthesis and Crystal Structure of Tetrabutylammonium 4-(2-Bromothiophene-5-Sulfanilamide)-Benzoate

Abstract  

Tetrabutylammonium 4-(2-bromothiophene-5-sulfanilamide)-benzoate crystallizes in C_2/C lattice with a = 18.3389(17), b = 16.540(16), c = 15.8280(15) ?, β = 116.959(2), V = 4279.5(7) ?³, Z = 4, and R = 0.0560. In the structure a very short centrosymmetric hydrogen bond and C=O···Br halogen bond interactions, together with N–H···O and C–H···O hydrogen bonds give a three-dimensional network.