Crystal structure of 3-pheny1-5-chloro-7-bromoisoxazolo[4,5-d]pyrimidine

The crystal and molecular structure of 3-phenyl-5-chloro-7-bromoisoxazolo-[4,5-d] pyrimidine, C₁₁H₅BrClN₃O, has been determined by X-ray techniques, and refined by Fourier and least-squares methods toR = 0·102 for 689 observed reflexions. The compound crystallizes in the orthorombic system:a = 15·72(4),b = 10·65(3),c = 6·72(3) Å,Z = 4, space groupPnam. The molecules lie on mirror planes, and all interatomic distances and angles within the molecule have reasonable values.Close molecular packing exists in layers (corresponding to crystallographic mirror planes) stacked normal toc.     

Influence of the spectator cation on the structure of anionic pyridine-2,6-dicarboxylato complexes of cobalt(II), nickel(II), and copper(II)

The structures of anionic pyridine-2,6-dicarboxylato (pdc^2–) complexes of cobalt, nickel, and copper have been studied. The stoichiometries and structures are very much dependent on whether KOH, Et₄NOH, or NaOH is used in the synthesis to deprotonate the H₂pdc ligand. Crystallographic results are: (1) K₂[Co(pdc)₂] · 7H₂O, orthorhombic, Pnna, Z = 4, a = 20.637(2)Å, b = 13.480(1)Å, c = 8.200(1)Å (2) K₂[Ni(pdc)₂] · 7H₂O, orthorhombic, Pnna, Z = 4, a = 20.648(1)Å, b = 13.375(1)Å, c = 8.2393(8)Å (3) [Co₂(H₂O)₅(pdc)₂] · 2H₂O, monoclinic, P2₁/c, Z = 4, a = 8.3880(6)Å, b = 27.384(2)Å, c = 9.6110(8)Å, = 98.271(6)° (4) [Ni(Hpdc)₂] · 3H₂O, monoclinic, P2₁/c, Z = 4, a = 13.679(1)Å, b = 10.0450(9)Å, c = 13.767(2)Å, = 115.184(7)° (5) Na₆[Co(H₂O)₆][Co(pdc)₂]₄ · 28H₂O, monoclinic, P2₁/n, Z = 2, a = 13.363(1)Å, b = 8.437(1)Å, c = 40.689(3)Å, = 91.288(5)° (6) Na[Ni(Hpdc)(pdc)] · 11.5H₂O, monoclinic, C2/m, Z = 4, a = 15.200(2)Å, b = 22.299(2)Å, c = 8.3596(7)Å, = 118.894(7)° (7) Na[Cu(Hpdc)(pdc)] · 3H₂O, monoclinic, P2₁/n, Z = 4, a = 9.516(4)Å, b = 14.917(6)Å, c = 12.247(5)Å, = 92.00(5)°. The potassium and sodium complexes have extensive K⁺—H₂O and Na⁺—H₂O networks. The fact the Et₄N⁺ ion does not appear in any of the complexes is likely due to the fact that it is incapable of forming the intricate cation—water and hydrogen-bonding networks observed in all of the other structures.     

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.     

Structures and properties of 1,4-dithiins and related molecules

A series of organosulfur compounds was characterized by NMR, IR, mass spectroscopy, cyclic voltammetry, and chemical analyses. The crystal structures of six compounds were determined: 1,3-dithioleno[4,5-e]naphtho[2,3-b]1,4-dithiin-2,5, 10-trione (1b), P , a = 7.665(4), b = 7.997(4), c = 11.443(5) Å, = 91.311(8), = 92.516(8), = 117.53(7)° 6,7-dimethylbenzo[1,2-b]1,3-dithioleno[4,5-e]1,4-dithiin-2,5,8-trione (2b), P2₁/m, a = 3.933(1), b = 12.864(2), c = 11.943(3) Å, = 99.161(4)° 6-phenyl-2-thioxo-6-hydrocyclopenta[2,1-b]1,3-dithioleno[4,5-e]1,4-dithiin-5,7-dione (3a), C2/c, a = 32.408(6), b = 3.8743(8), c = 27.123(5) Å, = 125.171(7)° 6-phenyl-1,3-dithioleno[4,5-e]3-pyrrolino[3,4-b]1,4-dithiin-5,7-trione (3b), P2₁/n, a = 7.9712(9), b = 6.1976(7), c = 55.978(6) Å, = 91.096(1)° 2,3,7,8-tetramethylthianthrene-1,4,6,9-tetraone (4), P2₁/c, a = 4.195(1), b = 17.924(5), c = 9.682(3) Å, = 98.509(5)° 3H,6H-1,4-oxathiino[6,5-2,1]naphtho[3,4-e]1,4-oxathiin-2,7-dione (5), P2₁/n, a = 9.3522(7), b = 7.8782(6), c = 17.118(1) Å, = 93.171(1)°. Several structures exhibited significant S—S intermolecular interactions, suggesting that the molecules might be precursors for preparing nonmetallic conductors.     

Crystal and molecular structure ofN-[1-(2-phenylethyl)-4-piperidinylium]-N-phenylpropanamide (fentanyl) citrate-toluene solvate

The crystal structure of fentanyl has been determined as part of a structure-activity relationship study on a congeneric series of 4-anilinopiperidines. The compound crystallizes as a citrate toluene solvate, C₂₂H₂₈N₂O · C₆H₈O₇ · C₇H₈, in the monoclinic space groupP2₁/c witha = 18.292(6),b = 9.825(4),c = 19.479(4) Å, = 107.43(3) °, andZ = 4. The structure was solved by direct methods using the program Simpel, and refined by block-diagonal least squares to anR value of 0.092. The torsion angle that describes the conformation of theN-phenyl ring relative to the piperidine ring is 123 ° and differs from that found in other 4-substituted anilinopiperidines (172–177 °).     

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.     

Reaction of dichloromaleic anhydride with 1,8-diaminonaphthalene: Synthesis and X-ray diffraction structure of 8,9-dichloropyrrolo[1,2-a]perimidin-10-one

The reaction of dichloromaleic anhydride with 1,8-diaminonaphthalene in refluxing toluene or 1,2-dichloroethane produces the new heterocyclic compound 8,9-dichloropyrrolo[1,2-a]perimidin-10-one in low yields. 8,9-Dichloropyrrolo[1,2-a]perimidin-10-one has been isolated by column chromatography and characterized in solution by IR, ¹H NMR, and UV/vis spectroscopies. The solid-state structure was unequivocally established by single-crystal X-ray diffraction analysis. 8,9-Dichloropyrrolo[1,2-a]perimidin-10-one crystallizes in the monoclinic space group P2 ₁/c, a = 7.475(1)Å, b = 10.650(2)Å, c = 14.468(2)Å, = 94.478(2)°, V = 1148.3(3) ų, Z = 4, and d _calc = 1.672 Mg/m³; R = 0.0289, R _w = 0.0762 for 1644 reflections with I > 2(I). The nature of the HOMO and LUMO in 8,9-dichloropyrrolo[1,2-a]perimidin-10-one has been determined by extended Hückel molecular orbital calculations, and these data are discussed relative to the cyclic voltammetric data obtained at a platinum electrode.     

Crystal and molecular structure of 2-bromobenzo[b]indeno[1,2-e]pyran

2-bromobenzo[b]indeno[1,2-e]pyran crystallizes in the monoclinic system: space groupP2₁/c,a = 7·508,b = 5·959,c= 26·172 Å, = 92·55 °. The structure has been determined by the heavy-atom method and refined by full-matrix least squares toR = 0·072 for 1027 observed reflections.The molecule is non-planar; the maximum deviations from the best plane occur at both ends of the length of the molecule, which results in distortion of the central portion from the expected geometry. The closest approach of two molecules, those related by a 2₁ axis, is 3·5 Å.     

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 structure of γ-2-trans-2,6-diphenylthian-1,1-dioxide-4-one oxime, C17H17NO3S

The X-ray crystal structure of -2-trans-2,6-diphenylthian-1,1-dioxide-4-one oxime is determined [C₁₇H₁₇NO₃S, space group P2₁ n, a = 8.177(1) b = 9.574(1)c = 19.730(5) Å, = 97.35(5)°]. The oxime group does not form an oxime dimer, but is involved in an O-H···O=S hydrogen bond.     

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.     

Crystal and molecular structure of bicyclo[2,2,1]hept-5-ene-2,3-endo-dicarboxylic acid

The crystal and molecular structure of bicyclo[2,2,1]hept-5-ene-2,3-endo-dicarboxylic acid, C₉H₁₀O₄, has been determined by single-crystal X-ray diffraction techniques. The crystals are monoclinic:P2₁/c,a = 11·009(5),b = 7·394(5),c = 10·479(5) Å, = 98 ° 22(3) andZ = 4. The least-squares refinement of 1826 diffractometer reflexions resulted in a conventionalR of 0·074. Bond distances and angles of the bicyclo [2,2, 1]hept-5-ene ring system agree well with other recently published structures of this type, including similar asymmetry of bond distances. Hydrogen bonding of the acid groups occurs between the molecules so as to form infinite chains in the direction of thea-axis. Large anisotropic thermal motions of the oxygen atoms of one carboxylic acid group are, presumably, the result of differences in hydrogen-bonding geometry.     

Crystal structure of the charge transfer complex 9-cyclohexyladenine-iodine

The crystal structure of the charge-transfer complex of iodine with 9-cyclohexyladenine, C₁₁H₁₅I₂N₅, has been determined, and refined by three-dimensional least-squares techniques. The crystals are monoclinic:P2₁/c,Z = 4,a = 9·1728(7),b = 12·289(1),c = 13·596(1) Å, = 99·564 °(6). The finalR value for 3629 reflexions is 0·039. The iodine forms a charge-transfer bond with N(1) of the adeninering, with an N—I bond length of 2·520(3) Å. The I—I—N(1) arrangement is approximately linear (bond angle, 177·1 °). The I—I molecule makes an angle of 21·5 ° with the plane of the adenine ring.Supported by N. I. H. Development Award 5-K4-GM-42572.     

Hydrogen-bonded dimer of N,N′-(5-n-butyl-5-oxodibenzo[b,d]phosphole-3,7-diyl)bis(benzamide) dimethylformamide solvate

The structure of a large wing-span phosphine, in the oxide form, N,N-(5-n-butyl-5-oxodibenzo[b,d]phosphole-3,7-diyl)bis(benzamide), C₃₀H₂₇N₂O₃P, cocrystallized with dimethylformamide (DMF), C₃H₇NO, is reported. The title compound is crystallized in a triclinic system with cell dimensions of a = 10.295(8) b = 12.743(5) c = 13.239(6) Å, = 108.14(3), = 108.16(5), = 101.20(4)°, and V=1484.4(5) ų, and forms a hydrogen-bonded dimer via two hydrogen bond linkages of the P—O ··· H—N type involving one of the two amide groups.     

Crystal and molecular structure of 2,5-dimethyl-3,4-diacetylfuran

The crystal and molecular structure of 2,5-dimethyl-3,4-diacetylfuran has been determined by direct methods using CuK. photographic data. Refinement by full-matrix least-squares methods gave a finalR factor of 0·097. The crystals are monoclinic: space groupP2₁/c,a =14·92(2),b = 4·09(1),c =16·68(3) Å and = 109·7(5) °;Z = 4. The furan ring of the molecule is planar, and the exocyclic atoms bound to the atoms of the ring lie close to the ring plane. The planes of the acetyl groups are tilted by 16 ° and 47 ° with respect to the ring plane. The exocyclic bond angles of this compound are significantly different from the equivalent angles in furan.     

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.     

Crystal structure and conformation of frentizole, [1-(6-methoxy-2-benzothiazolyl)-3-phenylurea, an antiviral agent and an immunosuppressive drug

Crystals of Frentizole (from ethanol/water) are monoclinic, space group P2₁/c, with a = 11.187(4), b = 7.392(2), c = 32.727(6) Å, = 92.77(2)°, Z = 8, D _o = 1.47 g/cm³, and D _c = 1.472 g/cm³. There are two independent molecules in the crystallographic asymmetric unit with very different conformations. In molecule A the urea group is in the plane of the benzothiazole ring (0.9°) whereas in molecule B the dihedral angle between them is 4.4°. The dihedral angle between the planes of the phenyl group and the benzothiazole ring are ±157° and ±12°, respectively, in the two molecules. The molecules are linked by a pair of N–H···N hydrogen bonds involving the urea nitrogen and two other N–H···N bonds involving the urea nitrogen and the nitrogen of the benzothiazole group.     

Crystal structure of ethidium bromide

Crystals of ethidium bromide (2,7-diamino-9-phenyl-10-ethylphenanthridinium bromide) monohydrate are monoclinic,a = 9·577,b = 10·698,c = 20·242 Å, = 106·34 °,Z = 4, space groupP2₁/c. The structure was determined with CuK. diffractometer data by direct methods, and was refined by full-matrix least-squares methods toR = 0·058 for 2151 observed reflexions.The phenanthridinium ring is slightly non-planar; the phenyl ring makes an angle of 97 ° with the mean plane of the phenanthridine ring, and the ethyl group is rotated about the N-C bond 84 ° out of the mean plane. One of the amino nitrogen atoms has a pyramidal and the other a planar configuration. Only three of the six active hydrogen atoms participate in a hydrogen-bonding scheme, which involves the pyramidal nitrogen atom, the water molecule and the bromide ion. The phenanthridine rings of two molecules related by a centre of symmetry are separated by 3·50 Å.E.S. and J.T. thank the National Research Council of Canada for financial support, and the University of British Columbia Computing Centre for assistance; C.E.B. thanks the U.S. Public Health Service for support under research grant DE-02670.     

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 5,5-dimethyl-2-p-bromophenylimino-Δ3-1,3,4-oxadiazoline

Oxidation of acetone-4-p-bromophenylsemicarbazone with lead tetraacetate yields only one isomer of 5,5-dimethyl-2-p-bromophenylimino-³-1,3,4-oxadiazoline, C₁₀H₁₀BrN₃O. Crystals of this compound are triclinic, space groupP¯1,a = 5·91(1),b = 9·52(1),c = 11·59(2) Å, =114·1(1) °, = 93·5(1) ° and = 108·8(1) °;z = 2 and the chemical composition is C₁₀H₁₀BrN₃O. Of 2306 independent reflexions examined, 877 were strong enough to be measured with integrated precession photographs using MoK radiation. The structure was refined using a full-matrix least-squares program to a finalR value of 0·064. The structure consists of planar phenyl and oxadiazoline rings, with a van der Waals interaction between a phenyl hydrogen atom and oxygen atom of the five member ring preventing the two rings from being co-planar; the H(13)-O(1) separation is 2·47 Å. TheZ-configuration of the product suggests a specific mechanism for the ring closure involving an organolead intermediate.