Crystallographic and conformational analysis of 2-methyl-3-(2-nitro-phenyl)-4-phenyl-[1,2,4]oxadiazolidin-5-one

Molecular and crystal structure of 2-methyl-3-(2-nitro-phenyl)-4-phenyl-[1,2,4]oxadiazolidin-5-one, C₁₅H₁₃N₃O₄, have been determined by single crystal X-ray diffraction study. The title compound is monoclinic, with a = 10.0313(8) Å, b = 9.0372(5) Å, c = 15.5964(14) Å, β = 96.926(7)^∘, Z = 4, D_x = 1.42 g/cm³, μ (Mo-K_α) = 0.105 mm⁻¹, and space group is P 2₁/c. The structure was solved by direct methods and refined to a final R = 0.036 for 1894 reflections with I > 4σ (I). The crystal structure is stabilized by C–H⋅sO type inter-molecular, C–H⋅sN and C–H⋅sO type intra-molecular, π–π stacking and edge to face (C–H⋅s π-ring) interactions. To enlighten conformational flexibility of the title molecule, selected two torsion angles are varied from −180^∘ to +180^∘ in every 10^∘ separetely and then molecular energy profile is calculated and construed.     

Synthesis and crystal structure of 1-acetyl-3-bromo-3-phenylazetidine and 1-phenyl-2-(N-acetyl-N-formyl)-aminoethanone

1-Acetyl-3-bromo-3-phenylazetidine (1), C₁₁H₁₂BrNO, has been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. It crystallizes in the space group P2 ₁/c with a = 8.633(1), b = 7.461(1), c = 17.204(1) Å, = 98.403(7)°, V = 1096.2(2) ų, Z = 4, D _calc = 1.540 g cm^–3. The azetidine ring is nearly planar since the four atoms are within ±0.039(5) Å of the mean square plane calculated for the heterocycle. The attempt to obtain a highly strained 2-azetine derivative from the above compound gave, surprisingly, 1-phenyl-2-(N-acetyl-N-formyl)-aminoethanone (2), C₁₁H₁₁NO₃. This compound has been also characterized by spectroscopic methods and single crystal X-ray analysis. It crystallizes in the space group P2₁2₁2₁, with a = 5.4719(3), b = 8.3205(6), c = 23.298(3) Å, V = 1060.7(2) ų, Z = 4, D _calc = 1.286 g cm^–3. The aminoethanone residue is in a near planar conformation where the torsion angles are 7(2)° for N–C–C–=O and –173(2)° for N–C–C–C(Ph).     

Crystal structure of 2-amino-3-methylpyridinium ortho-phthalate

A new crystal of 2-amino-3-methylpyridinium ortho-phthalate has been prepared and characterized by X-ray crystallography. The salt crystallizes in the monoclinic space group P2₁/c with a = 11.015(2) Å, b = 11.057(2) Å, c = 15.767(2) Å, = 90.00°, = 96.220(10)°, = 90.00°, V = 1909.0(5) ų, Z = 4. In the cell unit, the phthalate anion is linked with two pyridinium cations by NHO hydrogen bond on both sites of annular and exocyclic nitrogen atoms. The two pyridinium cations are arranged in a face-to-face pattern with a dihedral angle of 7.3° and a shortest aspectant distance of 3.4(1) Å between them, indicating the existence of – interaction. The C(5) atom is an electron donating center. The exocyclic N atom is an electron receiving center, which is consistent with features of imino resonance evidenced by bond lengths and angles. In the cell unit, two entities of pyridinium cation are aligned with each other in a face-to-face manner of electron receiving to donating center.     

Silver(I) complexes of 6-methyl-2-pyridinecarboxylic acid: the crystal structure of [Ag(MeC5H3NCOO)(MeC5H3NCOOH)]

Silver(I) complexes of 6-methyl-2-pyridinecarboxylic acid (HL) have been prepared, and the crystal structure of [Ag(L)(LH)] has been determined from X-ray diffraction data. This complex crystallizes in the monoclinic space group P2₁/n, with a = 13.4055(13), b = 7.1012(7), c = 15.588(2) Å, = 112.779(2)°, and Z = 4. Anionic [AgL₂]^– units are linked together by protons in approximately symmetrical linear O—H—O hydrogen bonds involving uncoordinated carboxylate oxygen atoms, to give polymeric chains. The most significant intermolecular interaction between adjacent parallel chains is offset ring stacking of pairs of aromatic rings with a perpendicular distance of 3.27 Å. The Ag coordination geometry is highly distorted tetrahedral, from two pyridine N atoms and two carboxylate O atoms, each ligand forming a five-membered chelate ring.     

Structure, thermal behavior, and IR investigation of bis(3-amino-1,2,4-triazolium)monohydrogen monophosphate

Chemical preparation, calorimetric studies, crystal structure, and IR spectrometric investigation of (C₂H₅N₄)₂HPO₄, denoted ATZP, are described. The compound crystallizes in the monoclinic system with C2/c space group. Its unit cell dimensions are a = 13.589(2) Å b = 11.105(2) Å c = 15.734(3) Å = 104.68(2)°, V = 2296.8(7) ų, and Z = 8. The structure of the title compound consists of a three dimensional network of H-bonds connecting all its components. The IR spectrum of ATZP is reported and discussed on the basis of group theoretical analysis.     

Crystal and molecular structure of triacanthine, 6-amino-3-dimethylallylpurine,a naturally occurring N(3)-substituted purine

The crystal and molecular structures of the naturally occurring, N(3)-substituted purine triacanthine (6-amino-3-dimethylallylpurine) are presented. Triacanthine crystallizes, from a saturated DMSO solution, in the monoclinic system, space groupP2₁/c. Crystallographic data are as follows:a = 12.451(4),b = 8.508(4),c = 11.365(3) Å, = 122.74(2) °,V _c = 1012.66 ų,Z = 4,D _m = 1.335(1),D _x = 1.333 g cm^–3. The structural solution was obtained by direct methods and has been refined, based on full-matrix least squares with 2124 observedF _o data, to a finalR value of 0.075. The principal molecular features are (1) the occurrence of the substituted purine as the amino tautomer, (2) a nearly planar purine ring system, and (3) a highly planar dimethylallyl group oriented approximately orthogonally to the purine ring system. The crystal packing is dominated by intermolecular hydrogen bonds involving the exocyclic amino group and the acceptor sites N(1) and N(9). Sheets of such hydrogen-bonded molecules are stacked along [10¯1]. Two distinct types of molecular overlaps are observed within these stacks.     

Synthesis and crystal structure of 3,4-trans-4, 5-trans-2-amino-3-cyano-1,3-dimethyloxycarbonyl-4, 5-di(3,4-methyl-enedioxylphenyl) cyclopentene

The 3,4-trans-4,5-trans-2-amino-3-cyano-1,3-dimethyloxycarbonyl-4,5-di-(3,4-methyl-enedioxylphenyl) cyclopentene has been synthesized and characterized by IR, ¹H NMR, Elemental analysis, and X-ray crystallography. It crystallizes in the monoclinic space group P2₁/n, with a = 10.936(3) Å, b = 10.142(3) Å, c = 20.001(4) Å, = 93.81(2)°, and D _calc = 1.390 g cm^–3 for Z = 4. X-ray analysis reveals that the phenyl groups and the alkoxyl carbonyl group are in the equatorial positions. The dihedral angles between the phenyl groups and the central five-membered ring are 73.08° and 62.15°. In addition, there are intermolecular hydrogen bonds in the crystal lattices.     

Intramolecular hydrogen bonding and tautomerism in N-(3-pyridil)-2-oxo-1-naphthylidenemethylamine

N-(3-pyridil)-2-oxo-1-naphthylidenemethylamine (C₁₆H₁₂N₂O) was studied by elemental analysis, IR, ¹H NMR, and UV–visible techniques and X-ray diffraction methods. The UV–visible spectrum of the compound was investigated in solutions effect polarity. The polarity of the some solvents was modifierly the additional (CF₃COOH) and [(C₂H₅)₃N]. The compound is in tautomeric equilibrium (phenol-imine O–H···N and keto-amine O···H–N forms) in polar and nonpolar solvents. The keto-amine form is observed in basic solutions of DMSO, ethanol, chloroform, benzene, cyclohexane, and in acidic solutions of chloroform and benzene, but not in acidic solutions of DMSO and ethanol. The compound crystallizes in the monoclinic, space group P2₁/a with a = 7.010(5) Å, b = 13.669(4) Å, c = 12.764(4) Å, = 101.23(4)°, V = 1199.6(10) ų, Z = 4, D _c = 1.375 g/cm³, (Mo K) = 0.088 mm^–1, R = 0.045 for 1658 reflections [I > 2(I)]. The title compound is not planar two Schiff base moieties A [C1–C11, O1] and B [N1, C12, C13, N2, C14, C15, C16] are inclined at an angle of 27.4(1)° reflecting mainly the twist about C12–N1 [C11–C12–N1–C13, 29.7(2)°]. There is a strong intramolecular hydrogen bond (O–H···N) of 2.529(2) Å.     

Crystal and molecular structure of bis(imazapyr)diaqua copper(II)

The imidazolinone herbicide imazapyr, 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid (H₂imz) interacts with Cu(II) leading to [Cu(Himz)₂(H₂O)₂] which crystallizes in the space group Pbca, with a = 12.5370(3) Å, b = 19.8500(5) Å, c = 22.7720(9) Å, and Z = 8. The Cu(II) atom is octahedrally surrounded by four nitrogen atoms of two Himz^– anions and two water molecules. Each Himz^– acts as a chelating ligand by means of N pyridine and N lactam atoms leading to five-membered chelate rings. The Cu N distances vary from 1.948(4) to 2.299(5) Å while the Cu O are 2.114(5) and 2.256(6) Å. The imidazol N-H are involved in short intramolecular hydrogen bonds with the carboxylate groups. The structure is stabilized by an intermolecular hydrogen-bonded network involving the water molecules and the carboxylate groups.     

The triethyl ammonium salt of O,O′-bis(o-tolyl) dithiophosphate [Et3NH]+[(2-MeC6H4O)2PS2]?

The X-ray structure of the triethyl ammonium salt of O,O′-bis(o-tolyl)dithiophosphate, [Et₃NH]⁺[(2-MeC₆H₄O)₂PS₂]⁻, has been determined. Crystal data: Monoclinic, P2₁/c, a = 15.4342(6) Å, b = 10.1913(4) Å, c = 14.0729(6) Å, β = 100.855(1)^∘, V = 2174.0(2) Å⁻³, Z = 4. The immediate environment around phosphorous is distorted tetrahedral with two sulfur and two oxygen atoms in the coordination sphere, with N–H–S bonding involving only one of the sulfur atoms.     

Crystal structure,thermal analysis,and IR spectroscopic investigation of bis(2-amino-6-methyl) pyridinium sulfate

Synthesis, crystal structure refinement, phase transitions studied by thermal analysis, and IR spectroscopic investigation of 2C₆H₉N₂ < eqid2 > ⋅SO₄²⁻ are reported. The title compound crystallizes in the monoclinic space group C2/c (no. 15) with a = 10.5068(4) Å, b = 10.2225(5) Å, c = 14.0422(7) Å, and β = 104.489(3)^∘. A crystal packing diagram shows layers built by all the components of the structure and centered by planes z = 1/4 and 3/4. The pyridine substituents stack forming channels parallel to the c direction with dimensions of 4.163(1) Å and 5.148(4) Å. Thermal analysis shows that the anhydrous compound possesses an irreversible weak phase transition.     

Crystal structure of a novel inner salt 4-guanidino-2-hydroxybenzoic acid

The guanidinium compound 4-guanidino-2-hydroxybenzoic acid, crystallizes in the orthorhombic space group Pbac with a = 8.090(2) Å, b = 12.470(3) Å, c = 16.430(3) Å, and Φ_calc = 1.564 Mg/m³ for Z = 8. The three-dimensional network is constructed through hydrogen bonds, electrostatic interactions and weak π–π stacking interaction among the guanidinium, carboxyl and hydroxy groups in the title compound.     

First example of cocrystals of polymorphic maleic hydrazide

The first cocrystals of polymorphic maleic hydrazide with 3-methyluracil have been studied by X-ray diffraction methods. They crystallize in the orthorhombic system, space group Pmcn, a = 6.440 (1) Å, b = 6.974 (1) Å, c = 22.829 (11) Å, V = 1025.3 (5) ų, Z = 4. The asymmetric unit contains one molecule of each compound. Planar ribbons of the (1:1) molecular complex are obtained through the formation of O–H···O and O–H···N intermolecular hydrogen bonds, just forming a well-known R² ₂(8) supramolecular synthon. Supramolecular assemblies are then formed by weak C–H···O and C–H···N hydrogen bonds through adjacent antiparallel ribbons.     

Synthesis and crystal structure of 2-benzoyl-4-methyl phenyl benzoate

The crystal structure of the title compound, C₂₁H₁₆O₃, has been determined. The compound crystallizes in triclinic space group PĪ with cell parameters a = 9.2240(9) Å, b = 9.8050(8) Å, c = 10.1610(11) Å, α = 94.749(6)^∘, β = 112.544(4)^∘, γ = 102.145(6)^∘ and Z = 2. The structure exhibits both intra and intermolecular interactions of the type C–H ⋅s O. The intermolecular interaction between the molecules form centrosymmetric dimers.     

Crystal structure and spectroscopic study of bis{1,3-bis[3-(5-amino-1,2,4-triazolyl)]triazenido-N′4,N2,N″4}nickel(II) tetrahydrate

The title compound [Ni(batt)₂]·4H₂O, in which Hbatt is 1,3-bis[3-(5-amino-1,2,4-triazolyl)]triazene, has been prepared and its crystal structure determined by X-ray diffraction methods. The compound crystallizes in the tetragonal space group I4/m (a = 10.5645(8) Å, c = 9.1336(6) Å, and Z = 2). The Ni(batt)₂ molecule has local 4¯ symmetry, but it is located on a crystallographic 4/m site and is disordered over the mirror plane. The ligand batt^– is tridentate with nitro-type coordination of the triazenido group and N⁴ coordination of the two outer triazolyl substituents. The complex has a distorted octahedral geometry with meridional configuration of the two nearly planar batt^– ligands. The geometry of the tridentate cavity is examined and a comparison is made with the Ni-terpyridyl system, which shows similar coordination around the nickel center. The FTIR, micro-Raman, and UV-vis spectra are analyzed in relation with the structure.     

Crystal structures of 2-pyrazinecarboxylato silver(I) and ammine 2,3-pyrazinecarboxylato disilver(I)

X-ray analysis has shown that the complexes of silver(I) with the anionic forms of 2-pyrazinecarboxylic and 2,3-pyrazinedicarboxylic acids are three-dimensional network polymers. Ag(C₅H₃O₂N₂) (1) crystallizes in space groupPna2₁ witha=7.028(2),b=11.510(3),c=6.949(2) Å andZ=4. Silver tetrahedral coordination occurs through three ligands: the first one acts as a bidentate chelator (Ag–O=2.539(4), Ag–N=2.334(4)Å), the second one involves one N pyrazine atom (Ag–N=2.196(4)Å) and the third one bonds through one O-carboxylato atom (Ag–O=2.323(4)Å). The dinuclear complex Ag₂(C₆H₂O₄N₂)(NH₃) (2) crystallizes in space groupP2₁/c witha=7.775(2),b=16.455(2),c=7.174(1) Å, -115.21(1)° andZ =4. Each of the two silver atoms shows a trigonal environment. The first silver atom involves two O carboxylic atoms (Ag–O=2.312(4), 2.374(4)Å) and one N pyrazine atom (Ag–N=2.277(3)Å) belonging to three different ligands. The second one involves one O carboxylic atom (Ag–O=2.364(3)Å) and one N pyrazine atom (Ag–N=2.304(4)Å) from the same chelating ligand and one N ammine atom (Ag–N=2.158(5)Å).     

Synthesis and crystal structures of two copper(I) π-complexes with 1-allyloxybenzotriazole of CuBr?C6H4N3(OC3H5) and 2CuCl?C6H4N3(OC3H5) compositions

Both compounds of CuBr⋅C₆H₄N₃(OC₃H₅) (sp. gr. P1, a = 7.633(1) Å, b = 9.987(1) Å, c = 14.898(2) Å, α = 104.75(1)^∘, β = 94.76(1)^∘, γ = 106.90(1)^∘) (I) and 2CuCl⋅C₆H₄N₃(OC₃H₅) (sp. gr. Cc, a = 11.2483(4) Å, b = 16.7076(6) Å, c = 7.2948(3) Å, β = 118.612(2)^∘) (II) composition were prepared by alternating-current electrochemical synthesis. In I due to a bridging function of organic moieties 16-membered cycles appear which are combined into ribbons {Cu₂Br₂[(C₆H₄N₃(OC₃H₅)]₂}_n. Each of two crystallographically independent copper atom possesses a trigonal-pyramidal arrangement with different degree of tetrahedral distortion. Distinctive numbers of hydrogen bonds around Br1 and Br2 atoms cause rather appreciable distinctions in copper–olefinic bond interaction effectiveness for each metal atom. In II Cu₂Cl₂ rhombs are joined to infinite chains oriented along [010] direction. Each ligand molecule is also coordinated through the C=C—bond of the allylic group to copper atom of one inorganic chain and through the nitrogen atom to a metal atom belonging to another copper-halide chain. Cu1 atoms is tetrahedrally surrounded by three chlorine atoms and nitrogen one, whereas a trigonal-planar arrangement of Cu2 atom is formed by two halogen atoms and slightly disordered olefinic group.     

Synthesis and crystal structures of 2-amino-3-cyano-4-(2-chlorophenyl)-1,4-dihydro-2H-pyrano[3, 2-h]quinoline and 2-amino-3-cyano-4-(2-chlorophenyl)-8-(2-chlorobenzylidene)-1,4,5,6,7,8-hexahydrobenzo[b]pyran

The title compounds 2-amino-3-cyano-4-(2-chlorophenyl)-1,4-dihydro-2H-pyrano[3, 2-h]quinoline 1 (C₁₉H₁₂ClN₃O, M _r = 333.77) and 2-amino-3-cyano-4-(2-chlorophenyl)-8-(2-chlorobenzylidene)-1,4,5,6,7,8-hexahydrobenzo[b]pyran 2 were synthesized and crystallized. The crystals of compound 1 are triclinic, space group P-1, a = 7.488(2), b = 9.127(3), c = 12.252(3) Å, = 73.58(2), = 78.38(2)°, = 75.39(2), Z = 2, V = 769.5(4) ų; The compound 2 crystallizes in space group P2₁/n, with cell parameters a = 13.582(2), b = 8.974(1), c = 16.960(2) Å, = 103.34(1)° and D _calc = 1.352 g/cm^–3 for Z = 4. X-ray analysis reveals that atoms C(1)—C(5) and O form a pyran ring in compound 1, which adopts half-chair conformation. In compound 2 the atoms C(12)—C(16) and O form a pyran ring which adopts boat conformation, another six-membered ring (C(8)—C(13)) adopts a half-chair conformation. In addition, there are intermolecular hydrogen bonds in the crystal structures 1 and 2.     

The molecular structure of [bis-triphenylphosphine-silver(I) stearate], [((C6H5)3P)2Ag(O2C(CH2)16CH3)], solubilization of long alkyl chain silver carboxylates

The crystal and molecular structure of [bis-triphenylphosphine-silver(I) stearate], [((C₆H₅)₃P)₂Ag(O₂C(CH₂)₁₆CH₃)], has been determined by single crystal X-ray analysis: the space group is PT witha=12.021(4),b=13.916(5)1,c=14.678(5) Å, =95.952(5), =101.249(6), =93.259(5)°,V=2388(2) ų, andD _calc=1.293 g/cm³ forZ=2. The silver is four coordinate: the carboxylate symmetrically chelates the silver while the triphenylphosphine ligands occupy the third and fourth coordination sites. The strong bonding nature of the phosphine ligands, as indicated by the Ag–P bond lengths, 2.446(3) and 2.424(3) Å, dominates the coordination sphere of the silver and forces the initial carboxylate ligand to rearrange from bridging to chelating resulting in weaker Ag–O bonds, as indicated by the extended Ag–O bond lengths, 2.399(8) and 2.449(8) Å. Unlike the free acid, the long hydrocarbon chain is not linear, and exhibits disorder in the lattice. The structure of the title complex explains the dramatic shift in solubility properties compared to the starting phosphine free silver carboxylate.     

Synthesis and crystal structure of a novel 3D supramolecular complex [Na(DC18C6-B)][Ni(mnt)<Subscript>2</Subscript>]

A supramolecular complex [Na(DC18C6-B)][Ni(mnt)₂] (1) (DC18C6-B = cis-anti-cis-dicyclohexyl-18-crown-6, isomer B; mnt = maleonitriledithiolate) has been prepared and characterized by elementary analysis, FT-IR spectroscopy and X-ray single crystal diffraction. It crystallizes in triclinic, space group P1 with crystallographic data: a = 7.974(4) Å, b = 14.343(7) Å, c = 15.559(8) Å, α = 96.230(8)^∘, β = 100.361(8)^∘, γ = 93.849(9)^∘, V = 1733.2(15) ų, Z = 2, D_calcd = 1.408 g/cm³, F(000) = 766, R₁ = 0.0491, wR₂ = 0.1018. The formula unit contains one [Na(DC18C6-B)]⁺ complex cation and one [Ni(mnt)₂]⁻ complex anion, which are constructed into an infinite chain-like structure through Na–N bonds. The resulting chains crisscross on the [Ni(mnt)₂]⁻ complex anions and further assemble into an unusual 3D supramolecular framework via the weak interactions.