Structure of 2-{2-[3-methyl-3-(2,4,6-trimethylphenyl) cyclobutyl]-2-oxoethyl}isoindole-1,3-dione

2-{2-[3-Methyl-3-(2,4,6-trimethylphenyl)cyclobutyl]-2-oxoethyl}isoindole-1,3-dione (C₂₄ H₂₅NO₃) was synthesized, and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes in the triclinic space group P-1, with unit cell parameters: a = 14.109(9) Å, b = 14.130(8) Å, c = 12.152(6) Å, = 105.62(5)°, = 113.75(4)°, = 98.78(5)°, V = 2039.8(19) ų, D _c= 1.223 g/cm³, and Z = 4. The crystal structure has two crystallographically independent molecules, I and II. These molecules are held together by weak intermolecular C—H···O interactions, forming a continuous chain. The dihedral angles between the N-substituted phthalimide moiety and cyclobutane ring in molecules I and II are 60.37(14) and 68.18(18)°, respectively.     

Synthesis and crystal structures of two potential gem-di(pyrazolyl)cycloalkane ligands, 1,1-di(pyrazol-1-yl)cyclohexane [C6H10(C3N2H3)2] and 1,1-di(pyrazol-1-yl)cyclopentane [C5H8(C3N2H3)2]

The species 1,1-di(pyrazol-1-yl)cyclohexane, C₁₂H₁₆N₄, crystallizes in the monoclinic space group P2₁/c with a = 8.340(2), b = 14.281(5), c = 10.153(3) Å, = 106.86(2)°, and Z = 4. The cyclohexane moiety has the chair conformation. The congener, 1,1-di(pyrazol-1-yl)cyclopentane, C₁₁H₁₄N₄, while not isomorphous, also crystallizes in space group P2₁/c with a = 14.350(2), b = 6.776(1), c = 11.043(2) Å, = 100.68(1)°, and Z = 4. The cyclopentane ring has a conformation in which four carbon atoms are essentially coplanar, while the fifth (that with the two pyrazolyl substituents) lies 0.63 Å from this plane, resulting in a bend of 41.3° across the C(2)···C(5) vector. The hydrogen atoms in each structure were located directly and their coordinates refined.     

The structure of 1-(p-fluorophenylmethyl)-2-(4-methyl-1-piperazinyl)-1H-benzimidazole hydrogen fumarate

The crystal and molecular structure of the title compound has been determined by X-ray analysis. The 1-(p-fluorophenylmethyl)-2-(4-methyl-1-piperazinyl)-1H-benzimidazole ion cocrystallizes with fumaric acid, (C₁₉H₂₂N₄F⁺·C₄H₃O ₄ ^– ), in space group P-1 with cell dimensions a = 9.938(1), b = 10.131(1), c = 12.712(1) Å, = 86.57(1), = 69.41(2), and = 67.22(2)°. The piperazine N4 atom is protonated and contacts the deprotonated O atom of the fumarate anion through a hydrogen bond. The benzimidazole ring is nearly planar and makes a dihedral angle of 111.25(12)° with the fluorophenyl ring. The piperazine ring adopts a chair conformation.     

Crystal structure of bis(morpholino)-disulphide

The crystal structure of bis(morpholino)-disulphide C₈H₁₆N₂O₂S₂, has been solved by the symbolic addition procedure using three-dimensional CuK diffractometer data. The system is monoclinic,a = 5·717(4),b = 8·880(7),c = 23·080(20) Å, = 107·8(1) ° andZ = 4. The structure was refined by fullmatrix least-squares methods to a conventional, unweightedR of 0·039 for 1441 observed reflexions. All hydrogen positions have been determined. The molecule possesses a pseudo-diad axis, the morpholine rings being in the chair conformation. Bonds at nitrogen are distorted pyramidal with the attached sulphur equatorial.     

Crystal and molecular structure of 3,5-bis(N,N-diethylimonium)-1,2,4-trithiolane-tetraiododi-μ-iododiinercurate(II)

The crystal and molecular structure of 3,5-bis(N,N-diethylimonium)-1,2,4-trithiolane-tetraiododi--iododimercurate(II), (S₃C₂N₂(C₂H₅)₄)Hg₂I₆, has been determined from a single-crystal X-ray diffraction study. The monoclinic unit cell, space groupP2₁/c, witha = 12·574(3),b = 15·777(4),c = 14·560(4) Å, and = 90·83(4) °, contains four formula-units. Three-dimensional intensity data were collected on an automatic diffractometer. Atomic parameters were refined by full-matrix least-squares methods to a conventionalR value of 0·05 for 1380 independent non-zero reflexions. The structure consists of (3,5-bis(N,N-diethyl-imonium)-1,2,4-trithiolane)²⁺ and Hg₂I ₆ ^2– ions. The cation contains a five-membered ring, S-S-C-S-C, which can be formed by oxidation of dithiocarbamato and thiuramdisulfide complexes.     

Crystal structure of 3-phenyl-7-bromoisoxazolo[4,5-d]pyridazin-4(5H)-one

The crystal and molecular structure of 3-phenyl-7-bromoisoxazolo[4,5-d]-pyridazin-4(5H-one, C₁₁H₆BrN₃O₂, has been determined from two- and three-dimensional X-ray data and refined by Fourier and least-squares methods toR = 0·101 for 1187 observed reflexions. Crystals of 3-phenyl-7-bromoisoxazolo-[4, 5-d]pyridazin-4(5H)-one are monoclinic:a = 7·67,b = 6·84,c = 20·52 Å, = 91·5 °,Z = 4, space groupP2₁/c. The benzene ring makes an angle of 4·5 ° with the plane of the isoxazole ring, and the other part of the molecule is slightly non-planar. The bond distances and angles compare well with those of other similar molecules. Two N-H...O hydrogen bonds join the two molecules related by a centre of symmetry. Close molecular packing is found in layers parallel to (100).     

Crystal and molecular structure of diphenylthiosulphodiimide

The crystal and molecular structure of diphenylthiosulphodiimide, C₁₂H₁₀N₂S₃, has been solved by the symbolic addition procedure using three-dimensional CuK diffractometer data. The system is monoclinic,a = 30·41(3),b = 5·601(5),c = 7·792(8) Å, = 108·77(1) °, space groupC2/c andZ = 4. The structure was refined by full-matrix least-squares methods toR = 0·096 for 926 observed reflexions. All hydrogen positions have been determined. The molecule possesses a crystallographic diad axis through the central sulphur atom. The planes of the phenyl rings make an angle of 30·8 ° with the closely coplanar central five atoms.     

Crystal structure of two lipophilic antifolates: 2,4-diamino-5-(n-hexyl)-6-methylpyrimidine and 2,4-diamino-5-(n-heptyl)-6-methylpyrimidine ethanesulfonate

The 5-hexyl (I) and the 5-heptyl (II) analogs of 2,4-diamino-6-methylpyrimidine both crystallize in the space groupP2₁/c withZ=4. Unit cell parameters of I are C₁₁H₂₀N₄·H₂O,a=17.204(3),b=4.609(9),c=16.765(2)Å,= 91.53(2)°; those of II are C₁₂H₂₃N₄ ⁺·C₂H₅SO₃ ^–,a=12.489(1),b=16.702(2),c=8.9558(7)Å,=99.208(8)°. The molecular packing of I contains one water, while II forms a salt with ethanesulfonic acid. The alkyl chain of I adopts an alltrans conformation; in contrast, II has onegauche orientation between carbons 2 and 3 of heptyl. These are the first structural data on two alkyl lipophilic antifolates with antineoplastic activity.     

Molecular assembly in an inclusion crystal of tris(2-benzimidazylmethyl)amine with 4-nitrobenzoic acid

A 1:2 inclusion compound of tris(2-benzimidazylmethyl)amine with 4-nitrobenzoic acid [(C₂₄H₂₁N₇) · (C₇H₅NO₂)₂] has been prepared and the molecular assembly in solid state has been determined by X-ray crystal structural analysis. The crystal structure (C 2/c, a = 25.488(5), b = 13.304(3), c = 21.479(4) Å, = 93.35 (3)°, Z = 8, R = 0.065) consists of discrete dimeric inclusion compounds joined together by N(5)...N(6) intermolecular hydrogen bonds between pairs of centrosymmetrically related benzimidazole rings of the hosts. There are two types of guest molecules in the crystal, one is incorporated within the cavity of the host via three intramolecular N—H···O hydrogen bonds while the other is situated outside the cavity and connected with the host through one O—H···N hydrogen bond. The – stacking interactions between guests and benzimidazole rings result in one-dimensional columns. The aromatic face–face interactions between neighbouring columns facilitate the assembly of those columns into two-dimensional layers.     

Crystal structures of thetrans-cyclooctene complexes of copper(I) chloride and silver nitrate

The crystal and molecular structures of the title compounds CuCl·C₈H₁₄ and AgNO₃·C₈H₁₄, have been determined by single-crystal X-ray diffraction techniques, and refined by full-matrix least squares. Both compounds crystallize in the orthorhombic space groupPbca witha=6.191(7),b=12.456(2),c=23.272(4) Å for CuCl·C₈H₁₄, anda=7.383(2),b=9.825(2),c=26.980(5) Å for AgNO₃·C₈H₁₄;Z=8 in both cases. FinalR factors are 0.047 and 0.029 respectively. The cyclooctene ring has the twist chair-chair (TCC) conformation, with approximateD ₂ symmetry, in both compounds, and the torsion angles around the double bonds are –134.2(4) and –137.0(4)° respectively. Slight lengthening of the metal-complexed double bond is attributed to enhanced olefin metal -donation of thetrans bond.     

Crystal structures of a series of 3,7-bis-(arylazo)-1,3,5,7-tetraazabicyclo[3.3.1]nonanes

The crystal and molecular structure of a series of 3,7-bis(arylazo)-1,3,5,7-tetraazabicyclo[3.3.1] nonanes (1a–d) have been determined by single crystal X-ray diffraction analysis. All four compounds have the same feature, that the tetraazabicyclononane unit assumes a cage-like structure with the aryltriazene moieties lying parallel to one another so that the aryl rings are held together by – stacking. Crystal data: 1a C₁₇H₁₈N₁₀O₄, triclinic, space group P – 1, a = 9.8899(10), b = 13.0845(13), c = 16.458(2) Å, = 94.095(2)°, = 107.004(2)°, = 111.027(2)°, V = 1863.5(3) ų and Z = 4; 1b, C₁₉H₁₈F₆N₈, orthorhombic, space group Pbca, a = 15.3210(8), b = 10.9512(6), c = 24.5698(13) Å, V = 4122.4(4) ų and Z = 8; 1c C₁₉H₁₈N₁₀, monoclinic, space group P2₁/n a = 6.3742(6), b = 13.7343(13), c = 21.542(2)Å, = 97.738(2)°, V = 1868.8(3) ų, and Z = 4; 1d, C₁₉H₁₈N₁₀, monoclinic, space group P2₁/c, a = 18.205(2), b = 17.398(2), c = 12.784(12) Å, = 109.480(2)°, V = 3818.0(6) ų, and Z = 8.     

Crystal structure of hexahydro-cis-(1-H,4a-H)-1-p-bromophenyl-1H,3H-pyrido[1,2-c][1,3]oxazine

The crystal and molecular structure of hexahydro-cis-(1-H,4a-H)-1-p-bromophenyl-1H,3H-pyrido[1,2-c][1,3]oxazine, (C₁₄H₁₈BrNO), has been determined from three-dimensional diffractometer data. The space group isP2₁/c; the unit cell has dimensionsa = 10·682(1),b = 21·606(2),c = 5·856(1) Å, = 90·0 ° (at 20 °C) and contains four molecules. The structure has been refined to a residual (R) of 0·056 using least-squares methods on 1240 independent non-zero reflexions.The molecular geometry and conformation of the bicyclic ring is discussed.     

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.     

Stereochemistry and hydrogen bonding of cytokinins: Crystal and molecular structure of 6-(4-hydroxy-3-methyl-cis-2-butenyl) aminopurine (cis-zeatin)

The title compound is C₁₀H₁₃N₅O, monoclinic,P2₁/a,a=13.829 (7),b=7.834 (7),c=20.138 (9) Å, and =100.75 (6)°. The structure was solved by direct methods and refined by least-squares techniques to anR factor of 0.079 for 1581 observed reflections. There are two crystallographically independent molecules (I andI). The N⁶-substituent is distal to the imidazole ring of the adenine moiety. It is interesting to note that the conformation of the N⁶-substituent relative to the adenine ring base in these two crystallographically independent molecules shows considerable resemblance with the preferred one usually adopted in other cytokinins. The angles between the mean planes of the adenine base and the N⁶-substituent are 65.6 and 63.3° for theI andI molecules, respectively. The molecules are linked by pairs of N(9)-H·N(3) hydrogen bonds. The dimer-like structures are stabilized by a three-dimensional network of O-H·O, O-H·N, N-H·O, and C-H·N hydrogen bonds.     

Crystal structures of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes

The crystal and molecular structure of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes (1–5) have been determined by single crystal X-ray diffraction analysis. In all five compounds, the tetraazabicycloundecane portion of the molecule assumes a cage-like, folded structure with the aryltriazene moieties aligned approximately parallel; the structure is held in the folded configuration by either intramolecular or intermolecular – stacking forces. Crystal data: 1 C₁₉H₂₂N₁₀O₄, monoclinic space group P2₁/c, a = 10.1846(7), b = 9.9556(7), c = 20.819(2) Å, = 98.725(1)°, V = 2086.5 (3) ų, Z = 4; 2 C₂₃H₂₈N₈O₄, triclinic, space group P, a = 6.7064(7), b = 12.9662(14), c = 14.054(2) Å, = 94.796(2), = 91.621(2), = 104.836(2)°, V = 1175.7(2) ų, Z = 2; 3 C₁₉H₂₂N₁₀O₄, monoclinic, space group P2₁/c, a = 14.237(2), b = 13.520(2), c = 11.5805(12) Å, = 113.514(2)°, V = 2044.0(4) ų, Z = 4; 4 C₂₁H₂₂N₁₀, monoclinic, space group C2/c, a = 54.247(3), b = 11.5531(7), c = 12.9670(7) Å, = 95.710(1)°, V = 8086.4(8) ų, Z = 16; 5 C₂₅H₃₂N₈ 0₄, monoclinic, space group P2₁/c, a = 10.2908(7), b = 16.5687(12), c = 15.1662(10) Å, = 94,188(1)°, V = 2579.0(3) ų, Z = 4.     

X-ray structure of 2,6-dimethoxy-7-methylpurine

The title compound (C₈H₁₀N₄O₂) is monoclinic, with a = 7.740(2), b = 17.044(7), c = 6.992(3) Å, = 100.60(1)°, and space group P2₁/c. Two O-methyl groups are coplanar with the pyrimidine ring. Whereas, the O(6)-methyl group is directed away from the imidazole ring toward the N(1) atom, the O(2)-methyl is pointed away from the N(1) atom toward the N(3) atom. Two intermolecular hydrogen bonds H(8)···N(1) and H(711)···O(2) of 2.48(2) and 2.58(3) Å make a linear arrangement of the molecules. The conformation of the O-methyl groups explains some results of thermal rearrangement of 2,6-dialkoxy-7-methylpurines and differences in alkylations of 2,4-dialkoxypyrimidines and 2,6-dialkoxy-7-methylpurines.     

Redetermination of the structure of bis[chloro-2-(2-hydroxy-4,5-dimethylphenylazo)-5,5-dimethyl-4,5,6,7-tetrahydrobenzothiazol-7-on] copper(II) complex

The crystal structure of C₁₇H₁₈ClCuN₃O₂S (M = 854.78, monoclinic, P2₁/c, a = 8.316(2), b = 18.461(4), c = 11.774(2) Å, = 99.64(3)°, V = 1782.0(7) ų, Z = 4) is formed by dimeric molecules [C₁₇H₁₈ClCuN₃O₂S]₂ with two monomeric units linked together by two chlorine atoms. The Cu atom is coordinated by two chlorine atoms, an oxygen atom, the azo nitrogen atom attached to the benzene ring, and the nitrogen atom of the thiazole ring, in the form of a distorted tetragonal pyramid.     

The crystal and molecular structure of N′,N′-(2-chlorobenziliden)-histamine

Summary The crystal and molecular structure of the N,N-(2-chlorobenziliden)histamine has been determined and refined by Fourier and least-squares methods using three-dimensional X-ray data collected at room temperature by photographic techniques. Crystal data is as follows:a = 8·76(2),b = 13·82(1),c = 9·88(2) Å, = 110·3(1) °,Z = 4. Space group:P2₁/c. The structure of the molecule is of the same tetrahydroimidazo[4,5-c]pyridine type found in spinaceamine. The benzene ring is rotated with respect to the other part of the molecule, which is formed by a non-planar tetrahydropyridine ring condensed with a planar imidazole ring. The bond distances and angles in these two rings are consistent with the observed distribution of the hydrogen atoms. Packing is mainly determined by a N-H ... N hydrogen bond, which joins the molecules in zig-zag chains running along [001].The authors wish to thank Professor T. Vitali for suggesting this research and providing the crystals, and Dr. A. Immirzi who kindly made available his computer programmes.     

Crystallographic studies of dihalogeno-tetramethylethylenediamine complexes of zinc,cadmium and mercury. I: crystal and molecular structure of dichloro-(N,N,N′,N′-tetramethylethylenediamine)zinc(II)

The crystal structure of dichloro-(N,N,N,N-tetramethylethylenediamine)zinc(II), C₆H₁₆Cl₂N₂Zn, has been determined from 1684 reflexions measured on a Siemens four-circle diffractometer (A.E.D.) using the /2-scan technique and CuK radiation. The crystals are monoclinic, space groupP2₁/c,a = 7·716(3),b = 13·335(9),c =11·545(5) Å, = 105·59(6) ° andZ = 4. The structure was solved by Fourier methods, and refined by full-matrix least squares to a finalR (conventional) of 6·7 %. Anisotropic thermal parameters were evaluated for the non-hydrogen atoms, but the hydrogen atoms were assigned the equivalent isotropic thermal parameters of the carbon atoms to which they were bonded. The geometry around the zinc atom is distorted tetrahedral, with the Zn-Cl and Zn-N average bond lengths of 2·207(4) and 2·08(1) Å respectively.     

Structure of 2-ethyl-8-methyl-2,8-diazaspiro[4,5]decane-1,3-dione hydrobromide (RS-86)

Crystals of the title compound, C₁₁H₁₈N₂O₂·HBr, are monoclinic, space groupP2₁, witha=7.339(3),b=13.246(7),c=7.340(4) Å,=116.94(5)°, andZ=2. The structure was solved by direct methods and refined by fullmatrix least-squares calculations to anR value of 0.046 for 1218 observed reflections. The piperidine ring, in a chair conformation, is perpendicular (90.6°) to the strictly planar pyrrolidine-2,5-dione ring. Br^– is hydrogen bonded to the positively charged piperidine N1 atom. Bond lengths and valence angles are comparable to those of various related compounds.