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.     

Crystal structure of tylophorine methiodide monohydrate,C25H30NO 4 + I−·H2O

The crystal structure of tylophorine (Chemical name 2,3,6,7 tetramethoxy phenanthro [9,10:6, 7] indolizidine. Contribution No. 0871.) methiodide monohydrate has been determined. C₂₅H₃₀NO ₄ ⁺ I^–·H₂0, triclinic, P,a=8.831(1)Å, b=10.842(2),c=13.902(2), =105.0(1)^o, =104.7(1), =97.3(1),V=1210.22ų, Z=2,D _x =1.428 g./cm^–3, (CuK)=1.54184Å, (CUK)=107.2 cm^–1, F(000)=544,T=295^oK,R=0.038,Rw=0.046, for 2331 observed reflections withI2(I). Apart from van der Waals forces, the structure is stabilized by two hydrogen bonds of the type Ow(H) ... O and Ow(H) ... I^– involving the water molecule as the donor and atom O4 of the methoxy group and I^– as acceptors.     

Structural and spectral studies of binuclear copper(II) 2-acetylpyridine 3-azacyclothiosemicarbazones with sulfato bridges

Structures of two binuclear copper(II) complexes with sulfato bridges and tridentate 2-acetylpyridine 3-azacyclothiosemicarbazone ligands have been solved. The complex-sulfato-bis{(2-acetylpyridine 3-hexamethyleneiminyl-thiosemicarbazonato)copper(II)} N,N-dimethylformamide, [Cu(Achexim)]₂SO₄·DMF, has the following structural properties: triclinic, P1¯(#2), a = 12.314(4), b = 15.885(4), c = 10.959(4) Å, = 103.25(2), = 103.60(2), = 109.94(2)°, V = 1843(2) ų, and Z = 2; for -sulfato-bis{(2-acetylpyridine 3-piperidylthiosemicarbazonato)copper(II)}chloroform, [Cu(Acpip)]₂SO₄·CHCl₃: triclinic, P1¯(#2), a = 11.657(1), b = 17.101(2), c = 10.338(1) Å, = 98.51(1), = 109.294(7), = 107.016(9)°, V = 1790.3(4) ų, and Z = 2. The size of the azacyclo ring significantly affects the stereochemistry of these binuclear complexes.     

A novel class of naturally occurring halogenated pyrroles, 1,1′-dimethyl-3,3′,4,4′,5,5′-hexabromo-2,2′-bipyrrole, 5,5′-dichloro-1,1′-dimethyl-3,3′,4,4′-tetrabromo-2,2′-bipyrrole, and 1,1′-dimethyl-3,3′,4,4′,5,5′-hexachloro-2,2′-bipyrrole

Crystal structure determinations of the three title hexahalogenated bipyrroles, (I) C₁₀H₆Br₆N₂, (II) C₁₀H₆Br₄Cl₂N₂, and (III) C₁₀H₆Cl₆N₂, reveal essentially planar pyrrole rings having dihedral angles of 64.7, 65.1, and 64.2° between the least-squares planes, favoring in each case a closer methyl–halogen conformation. All three complexes crystallize in the orthorhombic space group Pbcn with the following cell dimensions: (I) a = 12.654(3) Å, b = 8.853(2) Å, c = 13.753(3) Å, = = = 90°, Z = 4; (II) a = 12.438(6) Å, b = 8.753(6) Å, c = 13.696(3) Å, = = = 90°, Z = 4; (III) a = 12.088(6) Å, b = 8.566(4) Å, c = 13.486(8) Å, = = = 90°, Z = 4.     

Short H· · ·H distances in norbornene derivatives

A short H···H intramolecular interaction was reported previously for an anhydride of syn-sesquinorbornene. The synthesis and structure of a such an anhydride with an additional five-membered dithiole ring has been investigated. While hydrogen atom positions are not accurately located, the 1.62 Å separation indicates this molecule is a candidate for the shortest H···H interaction. Two cycloadducts of norbornadiene, which literature suggests might exhibit additional short interactions, are reported also; however, the isomers with minimal intramolecular interactions are the isolated products. C₂₂H₂₀O₃S₂, 3, crystallizes in P with a = 10.881(4), b = 13.712(8), C = 6.548(8) Å, = 101.32(6), = 107.49(5), = 90.49(4)°, D _calc = 1.445 g cm^–3, and Z = 2, C₂₁H₂₀O₄Cl₈, 5, in P2₁/n with a = 8.168(2), b = 13.488(4), c = 23.500(6) Å, = 94.72(2)°, D _calc = 1.597 g cm^–3, and Z = 4, C₂₁H₂₈O₄, 6, in P> with a = 12.667(2), b = 12.792(2), c = 12.540(2) Å, = 113.51(1), = 98.18(1), = 74.39(1)°, D _calc = 1.276 g cm^–3, and Z = 4.     

Choline sodium 4-amino-1-β-d-ribofuranosyl-2-(1H)-pyrimidionone diphosphate tetrahydrate (Sodium cytidine diphosphocholine,C14H33N4NaO15P2)

This communication presents a preliminary report on the crystal structure of this important nucleotide, involved in lecithin synthesis in animal tissues. The crystallographic data were recorded using a four-circle diffractometer with Cu-K x-radiation. Crystal data: orthorhombic, space groupP2₁2₁2₁ (No. 19),Z = 4,a = 6.98 pm,b = 123.6 pm,c = 292.3 pm,U = 2.522 nm³. The structure was solved by means of a Patterson and electron-density maps and refined by several cycles of least-squares using isotropic temperature factors toR = 0.14.The torsion angles associated with the furanosyl ring are, in general, at the very extreme of the range commonly observed for C(2) endopuckering (Altona and Sundaralingam, 1972); their values are 1 = 319 °, 2 = 47 °, 3 = 326 °, 4 = 13 °, 5 = 18 °. The phase angle of pseudorotation, calculated from these values using the formula given by Altona and Sundaralingam (1972) is 139 °. This shows the ribose ring to be slightly nearer to the C(1) exopuckering than the C(2) endopuckering conformation, but remote from being a C(3) endo-conformer. The sugar ring, in fact, is very close to being an idealized twist conformer. This is supported by a four-atom least-squares planes study, and is consistent with the high value of 237 ° (Sundaralingam, 1973).Backbone torsion angles associated with the structure are = 57 °, = 133 °, = 174 °, and = 291 °. is some 7 ° less than the preferred minimum value for C(2) endopuckering.     

Rotational disorder in 1,5-dihydroxy xanthone

The crystal structure of 1,5-dihydroxy xanthone obtained from Callophyllum trapezifolium has been determined (C₁₃H₈O₄), Mr = 228.21, a = 5.547(5), b = 5.186(5), c = 16.487(5) Å, = 91.40(1), Z = 2 and V = 474.1(6) ų. The xanthone molecule is planar and exhibits rotational disorder in the crystal. The packing of the molecules in the crystal lattice is due to inter- and intramolecular O–H O hydrogen bonds forming infinite chains.     

Crystal data,optics and vibrational spectra of potassium hydrogen squarate monohydrate,KHC4O4·H2O

Single crystals of potassium hydrogen squarate monohydrate have been prepared, and the unit cell, space group and crystal optics determined:a = 8·641(1),b = 10·909(1),c = 6·563(2)Å, = 99·807(5) °,Z = 4,P2₁/c,n = 1·411(1),n = 1·674(1),n = 1·793(2), 2V(–) = 59·1(8) °,n ¦¦_t,n :a = 2·3(2) ° in obtuse . Infrared and oriented Raman spectra have been obtained, and compared with the spectra of both the acid and the [C₄O₄]^2– ion. The squarate ring is itself very nearly orthorhombic, with symmetry axes parallel to the C-C bonds. The rings lie approximately in (001), with the C-C bonds aligned witha andb.     

Anticooperative C—C—H···O···H—O hydrogen bonding in 5β-Hydroxy-5α-ethynyl-10β-methyl-Δ1(9)-octalin-2-one

In the x-ray crystal structure of the alkynol 5-hydroxy-5-ethynyl-10-methyl-¹⁽⁹⁾-octalin-2-one [C₁₃H₁₆O₂, Pbca, a = 10.244(7), b = 12.734(2), c = 17.125(2) Å, Z = 8], the hydroxyl and ethynyl groups are involved in a hydrogen bond arrangement C—C—H···O···H—O, which is supposed to be anticooperative, i.e., weaker than the sum of two isolated hydrogen bonds.     

Structure, thermal behavior, and IR investigations of (C6H9N2)H2PO4

Chemical preparation, X-ray single-crystal, thermal behavior, and IR spectroscopy studies of a new dihydrogenmonophosphate associated to an organic cation, the 3-(ammoniummethyl)pyridine dihydrogenmonophosphate (denoted as AMPP) are described. The AMPP crystallizes in the monoclinic system with P2₁/c space group. The unit cell dimensions are a = 5.8465(2) Å, b = 19.9776(9) Å, c = 7.3103(3) Å, = 90.848(3)° with V = 853.74(4) ų and Z = 4. The structure has been solved using direct method and refined to a reliability R factor of 0.0393. The structure of AMPP includes three types of hydrogen bonds. The first one, O H O, links the H₂PO₄ groups to form infinite inorganic chains [H₂PO₄]n ^n–, parallel to the c axis. The two other types, O H N and N H O assemble inorganic chains so as to build up a three-dimensional arrangement.     

Crystal and molecular structure of 1,N6-ethenoadenosine hydrochloride

The X-ray structure of 1,N ⁶-ethenoadenosine hydrochloride, C₁₂H₁₄N₅O₄Cl, has been determined from three-dimensional diffractometer data and refined by full-matrix least-squares techniques. The crystals are monoclinic:P2₁ No. 14,a=6.1540(5),b=18.511(1),c=6.7412(4) Å,=112.602(5)°,andZ=2; finalR=0.045 for 2662 observed reflections. The crystal and molecular structure of Ado·HC1 is very similar to that of Ado·HC1. On the other hand, the dimensions and conformation of the Ado·H⁺ cation are drastically different from those of Et Ado·H⁺. The adenosine·H⁺ moiety is not planar but has an S shape. The ribose is 2-endo-3-exo puckered, with ag ⁺ side chain; the glycosidic torsion angle is in theanti region. The structure contains a three-dimensional network of H bonds in which also C-HA interactions seem to play an important role. There is no base stacking in the structure.     

Crystal structure of a (25R)-2α,3α-epoxy-5α-spirostan-6, 23-dione hemi-ethyl acetate solvate

The compound (25R)-2,3-epoxy-5-spirostan-6,23-dione, crystallizes as a hemi-ethyl acetate solvate, having two host molecules of similar conformation per molecule of ethyl acetate, in the asymmetric unit. The O atom of the epoxy group is -oriented. The presence of the epoxy group disturbs the chair conformation in the ring A of the steroidal nucleus. Ring A has a C5,C10 half-chair conformation. The six-membered rings B, C, and F have chair conformation as expected. The D ring adopts a C14-envelope conformation and the E ring is midway between a C22,O3 half-chair and a C22-envelope conformations. The A/B, B/C, and C/D ring junctions are trans. Crystal data: C₂₇H₃₈O₅·1/2C₄H₈O₂, Monoclinic, space group P2₁, a = 7.7363(18) b = 28.769(12) c = 12.038(6) Å, = 90.88(5), V = 2679.0(10) ų, Z = 4. The packing of the molecules is assumed to be dictated by van der Waals interactions and by intermolecular C—H ··· O hydrogen bonds.     

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.     

A comparison of the crystal structures of (dabcoH2)CuCl4 and (dabcoH2)CuCl4⋅H2O

The crystal structures of the anhydrous and monohydrated (dabcoH₂)CuCl₄nH₂O salts (n = 0,1) have been determined and a comparison of their crystal structures has been reported. The anhydrous salt is monoclinic P2₁/c with a = 9.045(2) Å, b = 6.9270(10) Å, c = 18.767(4) Å and = 90.07(3)° with V = 1175.8(4) ų. The hydrated salt is also monoclinic P2₁/c with a = 9.266(2) Å, b = 9.395(2) Å, c = 14.386(3) Å and = 93.32(3)° with V = 1250.3(5) ų. The structures of the two salts are closely related. Both compounds contain isolated distorted (compressed) tetrahedral CuCl₄ ^2– anions, diprotonated dabco cations, and in the case of the hydrated salt, lattice H₂O molecules. In the anhydrous salt, each of the two N–H⁺ groups of the dabcoH₂ ²⁺ dications form bifurcated hydrogen bonds to chloride ions on adjacent CuCl₄ ^2– anions along the c axis, thus forming chains running parallel to the c axis. In the hydrated salt, a water molecule is inserted into one of the pair of bifurcated hydrogen bonds, forming instead N–H O–H CuCl₄ ^2– linkages. The chains thus formed are cross-linked by O–H Cl hydrogen bonds between the chains. Because of this additional hydrogen bonding, the CuCl₄ ^2– anions in the hydrated salt are distorted further from tetrahedral geometry.     

Synthesis and structural characterization of the bitopic ferrocene-based tris(pyrazolyl)methane ligand Fe[C5H4CH2OCH2C(pz)3]2 (pz = pyrazolyl ring)

The structure of Fe[C₅H₄CH₂OCH₂C(pz)₃]₂ (pz = pyrazolyl ring) contains 1.5 independent molecules in the asymmetric unit. One molecule has no imposed symmetry with the iron atom located on a general position while in the other the iron atom is located on an inversion center. The two independent molecules are arranged into a three-dimensional supramolecular structure by a series of C—H s N and C—H s O weak hydrogen bonding interactions and C—H s interactions. The crystals are triclinic, space group, P , with a = 8.1202(4) Å, b = 16.7209(9) Å, c = 18.6540(10) Å = 85.8270(10), = 85.4740(10), = 81.5910(10), and Z = 3     

Crystal structure of a spirophosphonium compound,C24H18ClN2P,CH3OH

10,10-(5H,5H)-spirobiphenophosphazinium chloride is one of the few examples of a spirophosphonium salt reported in the literature. This compound crystallized in space groupP2₁/c witha = 12·293(7),b = 13·279(8),c = 17·56(1) Å, = 130·43(3) ° andZ = 4. The finalR index was 0·057. The results of the X-ray analysis indicated that this phosphorus heterocycle may indeed possess aromatic character. This contention was supported in solution by a³¹ P nmr study.Taken in part from the thesis submitted by R. N. Jenkins for the Ph.D. degree, August 1972.     

Structure of the larvicideN-(2-chlorobenzoyl)-N′-[4-(2-chloro-3,3,3-trifluoroprop-1-enyl)phenyl]urea,C17H11Cl2F3O2N2

Mw=403,2 amu,P2₁/c,a 18.944(8) Å,b=8.540(4) Å,c=10.794(7) Å,=98.11(4)°,V=1729(2) ų,Z=4,D _x=1.548 g·cm^–3, (MoK)=4.26 cm^–1; m.p. 202–204°C. FinalR=0.083 for 1632 independent observed reflections having 2 (Mo K)<50° andI>2 (I). The molecule has an extended overall nonplanar conformation with onecis and twotrans-C(O)-NH- units and intramolecular hydrogen bridges. The relatively highR factor is on account of conformational disorder of the trifluoromethyl and chloro substituents of the 2-chloro-3,3,3-trifluoropropenyl moiety.     

Synthesis and crystal structure of [WI(CO)(cis-dppen) η2-MeC2Me)2]I·CH2Cl2 {cis-dppen = bis(diphenylphosphino)ethene}

The complex [WI(CO)(cis-dppen)(²-MeC₂Me)₂]I·CH₂Cl₂(1) is prepared as a by-product from the reaction of equimolar quantities of [WI₂(CO)(NCMe)(²-MeC₂Me)₂] and cisdppen {dppen = bis(diphenylphosphino)ethene}. Complex 1, [WI(CO)(cis-dppen)(²-MeC₂Me)₂]I·CH₂Cl₂ crystallizes in the triclinic space group with a = 11.189(13), b = 12.331(14), c = 15.395(17) Å, = 83.61(1), = 86.06(1), = 64.48(1)°, U = 1904 ų, and Z = 2. The metal environment in the cation can best be considered as a distorted octahedron with the two but-2-yne groups taking up individual sites trans to phosphorus atoms of the dppen ligand. The coordination sphere is completed by mutually trans-carbonyl and iodide groups.     

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.     

Crystal structure of 4,6-dinitro-1-(5-tetrazolyl)-1H-indazole trihydrate

The title compound, C₈H₄N₈O₄·3H₂O, crystallizes in space groupP¯1 with cell constantsa=7.022(1),b=9.507(2),c=10.906(2) Å,=84.99(1),=71.89(1),=72.56(1)°,Z=2, andV _c =660.2 ų. The structure was solved by direct methods using diffractometer data and was refined by full-matrix least-squares methods to anR value of 0.060 for 2112 observed reflections. The molecule, consisting of a phenyl ring fused to a pyrazole ring with a tetrazole ring connected to it equatorially, is planar except for the N(7) nitro-group oxygen atoms. The structure is stabilized by a three-dimensional network of O-HO, O-HN, and N-HO hydrogen bonds through the water molecules.