Crystal structure of syn-1-acetyl-9′aH-8′- methoxyspiro[indole-3,2′-oxeto[3′,2′:4,5]furo[3,2-g][1] benzopyran]2,6′-dione

The crystal structure of syn-1-acetyl-9a-hydro-8-methoxyspiro[3H-indole-3,2(2aH) oxeto[3,2-g]furo[3,2-g]benzo[ b]pyran-2,6-dione 1 was determined by X-ray diffraction analysis. It possesses P2(1)/c space group symmetry, with a = 12.391(3), b = 15.035(3), c = 9.5435(19) Å, = 93.66(3), and D _calc. = 1.517 Mg/m³ for Z = 4.     

Investigation of lignin models of the biphenyl type by X-ray crystallography and NMR spectroscopy

Lignin models of the biphenyl type have been synthesized and crystal structures of two of them have been determined. The tetraacetate of 5,5-bis(hydroxymethyl)-3,3-dimethoxy-2,2-biphenyldiol crystallizes in space group witha=11.319(2),b=12.232(6),c=9.242(3) Å, =101.66(3)°, =108.14(2)°, =79.08(2)° andZ=2.R=0.036 (2720 observed [I>3(I)] reflections). The acetate of 5,5-di-tert-butyl-2,3,3-trimethoxy-2-biphenylol crystallizes in space group witha=11.972(2),b=21.621(3),c=9.834(1) Å, =91.18(1)°, =113.13(1)°. =98.42(1)°, andZ=4.R=0.050 (8129 observed [I>3(I)] reflections).¹H NMR and¹³C NMR data for the above-mentioned compounds and a third model, the diacetate of 5,5-bis(1-hydroxyethyl)-2,2,3,3-tetramethoxybiphenyl, are reported. Observed signal positions are compared with those calculated on the basis of crystal structure data. The possibilities to obtain structural information about biphenyl structures in lignins from NMR spectra are discussed.     

Hydrogen-bond networks in the mono- and diprotonated cyclic diamine [9]aneN2S

The hydrogen-bond networks in the mono- and diprotonated cyclic diamine, 1-thia-4,7-diazacyclononane, [9]aneN₂S, have been examined. Crystals of the monoprotonated, form [9]aneN₂S HCl, contain a ribbon-like network of alternating strong and weak intermolecular N H Cl hydrogen bonds and weak intramolecular N H N hydrogen bonds. Crystal data for [9]aneN₂S HCl: monoclinic, a = 6.6640(6) Å, b = 10.3493(9) Å, c = 6.9807(6) Å, = 108.847(1)°, V = 455.63(7) ų, space group P2₁, Z = 2. In the di-protonated form, [9]aneN₂S 2HBr, the ribbon-like network comprises strong intermolecular and weak intramolecular N H Br hydrogen bonds. Crystal data for [9]aneN₂S 2HBr: orthorhombic, a = 12.5918(13) Å, b = 8.0753(9) Å, c = 10.6856(11) Å, V = 1086.5(2) ų, space group Pnma, Z = 4. The chloride anions of [9]aneN₂S HCl align in interlocking columns in the a- and c-direction whereas the bromide anions in [9]aneN₂S 2HBr occupy channels in the b-direction.     

A comparison of the coordination preferences of Zn, Co, and Cd(II) with the heteroscorpionate ligand (2-hydroxy-3-t-butyl-methylphenyl)bis (3,5-dimethylpyrazolyl)methane

Reaction of the Zn, Cd, or Co nitrate salts with the deprotonated ligand (2-hydroxy-3-t-butyl-methylphenyl)bis(3,5-dimethylpyrazolyl)methane (L1O^–) in methanol produced the following complexes: [(L1OH)Zn(NO₃)₂] in two isomorphs, a = 40.983(8) Å, b = 9.571(2) Å, c = 15.667(8) Å, = 90, = 106.38(1), = 90, C2/c, and a = 13.027(3) Å, b = 14.781(4) Å, c = 16.107(3) Å, = 90, = 105.30(1), = 90, P2₁/n; [(L1OH)Cd(pz)(NO₃)₂] a = 14.7476(2) Å, b = 13.5411(2) Å, c = 16.7223(2) Å, = 90, = 110.3840(10), = 90, P2₁/c; and [(L1O)Co(pz)(NO₃)] a = 11.4240(2) Å, b = 13.4498(2) Å, c = 13.8056(2) Å, = 105.2080(10), = 105.8130(10), = 112.7470(10), P . The Zn adopts a pseudotetrahedral four-coordinate geometry where the potentially tridentate ligand is actually bidentate with a protonated and uncoordinated phenoxy arm. The Co complex is pseudooctahedral six-coordinate where the phenoxy arm is deprotonated and coordinated. Finally the Cd complex is seven-coordinate but the metal is not coordinated through the phenoxy group that is again protonated.     

Synthesis,characterization and crystal structure of oxovanadium(IV) complex with tridentate o-van-gly and bidentate phenanthroline

A novel oxovanadium(IV) complex with tridentate schiff base and bidentate phenanthroline ligands, VO(o-van)(phen) 2H₂O[o-van-gly: o-vanillin-glycine; phen: phenanthroline], was synthesized and characterized by elemental analysis, IR and UV-vis spectra. The crystal structure was determined by X-ray single crystal diffraction analysis. The crystal of title complex (C₂₂H₂₁N₃O₇V, M_w = 490.36) belongs to triclinic, space group P-1 with the following crystallographic parameters: a = 9.247(3) Å, b = 10.125(4) Å, c = 13.100(5) Å, = 106.343(6), = 96.042(7), = 101.726(7), V = 1135.0(7) ų, Z = 2, D_c = 1.435 Mg m^–3, (MoK = 0.485 mm^–1, F(000) = 506, and final R₁ = 0.0779, wR₂ = 0.1598 for observed reflections 1606 (I > 2(I)). V(IV) is six-coordinate with three oxygen atoms and three nitrogen atoms in a distorted octahedral geometry. The complex forms a 3-D network via – stacking and hydrogen bonds.     

Synthesis and X-ray structure analysis of 2-acetylamino-benzoic acid

The title compound crystallizes in the orthorhombic space group Fdd2 with unit cell parameters a = 10.848(1) Å, b = 30.264(1) Å and c = 10.577(1) Å, V = 3472.47(2) ų, and Z = 4. The final reliability index is 0.030 for 700 observed reflections. Nitrogen of the amide group and carbon atom of the acid group deviate significantly below and above the plane of the phenyl ring. The crystal cohesion is accentuated by N—HO and O—HO hydrogen bonds.     

Synthesis and structure of 4-R,5-R-[5-(hydroxy-diphenyl-methyl)-2, 2-dimethyl-[1,3]dioxolan-4-yl]-phenyl-methanone, a chiral ligand building block

A triphenyl analog of taddol, 4-R,5-R-[5-(hydroxy-diphenyl-methyl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-phenyl-methanone, has been synthesized and structurally characterized. This molecule could act as a chiral ligand building block in the creation of tuned taddol analogs. Structural analysis of the title compound reveals that the hydroxyl group is involved in an intramolecular hydrogen bond and does not take part in any intermolecular interaction. Crystal packing is influenced by C–H O hydrogen bonding and phenyl phenyl interactions. Crystal data: Triclinic, P1 (No. 1), a = 5.9343(4) Å, b = 8.2367(17) Å, c = 10.987(2) Å, = 88.290(6), = 75.442(4), = 80.655(6), V = 512.86(15) ų, Z = 1, D _calc = 1.258 mg/m³. Final residual values were R ₁ = 0.0407 for 3022 observed data (I > 2s(I) ) and wR ₂ = 0.0941 for all 3524 unique data.     

Characterization and structural analyses of trimethoxy and triethoxybenzo[b]thiophene

The crystal and molecular structures of two methoxybenzo [b] thiophenes have been determined by three-dimensional, single-crystal X-ray diffractometry. Both 3-(3,4,5-trimethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene and 3-(3,4,5-triethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene (hereafter referred to as I and II, respectively) crystallize in the triclinic centrosymmetric space group (No. 2, C¹) with two formula units per cell with a = 6.842(1) Å, b = 12.602(2) Å, c = 13.815(2) Å, = 94.80(1)°, = 98.27(2)°, and = 100.59(2)° and a = 10.600(1), b = 11.415(2), c = 12.137(2) Å, = 94.57(1)°, = 101.18(1)°, and = 110.45(1)°, respectively. The phase problems were solved by direct methods and the respective final full-matrix least-squares refinements converged to R = 0.039 and 0.068. The structures differ in the orientation of the trimethoxy and triethoxy groups of the benzoyl ligands. The molecules in the crystal lattice are held together by van der Waals forces. Selected bond distances, angles, and torsion angles are tabularized as well as reference to the synthesis of the title compounds and peripheral studies.     

Hydrogen bonding in 2-hydroxy((di)thio)benzoates. I. X-ray structures of 2,6-dimethylpiperidinium salts

X-ray structural data are reported for 2,6-dimethyl-piperidinium-2-hydroxybenzoate (C₁₄H₂₁NO₃, orthorhombic,P2₁2₁,2₁, (19);a=7.983(1)Å,b=12.680(2)Å,c=13.838(2)Å;Z=4;R=0.042) and for two polymorphs of 2,6-dimethylpiperidinium-2-hydroxythiobenzoate (C₁₄H₂₁NO₂S), an-form (monoclinic,P2₁/n (14);a=8.005(4)Å,b=22.150(2)Å,c=8.672(4)Å,=101.91(6)°;Z=4;R=0.059) with an intramolecular O-HS hydrogen bond, and a-form (orthorhombic,P2₁2₁2₁ (19);a=8.188(1)Å,b=14.781(2)Å,c=24.163(4)Å;Z=8;R=0.15) with an intramolecular O-HO hydrogen bond. The intra-and intermolecular hydrogen bond patterns are discussed, including the literature data of 2,6-dimethylpiperidinium-2-hydroxydithiobenzoate.     

Bis(2,6-(2′,6′-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II)

Bis(2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II) was prepared by the reaction of 2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenol with nickel chloride. The title complex crystallized in P2₁/c, with cell dimensions a = 9.962(2) Å, b = 12.087(3) Å, c = 24.445(6) Å, and = 97.032(5), giving a volume of 2921.4(13) ų. The bis(2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II) adapts an ideal parallelogram, in which the Ni atom is coordinated with two phenolic oxygen atoms [O(1), O(1A)] and two imino nitrogen atoms [N(1), N(1A)].     

Anticancer agent development. 5. X-ray structure and1H nmr spectral analysis of (1α,2α,5α,6α)-2,6-bis(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane-4,8-dione

The title compound, C₂₀H₁₄O₈, Mr=382.3, crystallized from chloroform in the centric space group P¯1 witha=6.516(4),b=6.798(3),c=9.545(7) Å,=85.31(5),=73.87(5), =79.59(4)°,V=399.2 ų, and D_calc=1.59 g cm^–3 forZ=1. Least-squares refinement of 1035 observed [F_o5(F_o)] reflections led to the final agreement index ofR=0.074. The molecule resides on a crystallographic center of inversion and is disordered into two different conformations. This manifests itself as a 50/50 disorder at O(4), C(2), and C(3). The observed structure reveals acis relationship between the bridgehead hydrogen atoms and the aryl rings. The 90 MHz¹H nmr spectrum of the title compound exhibits an AAXX spin system with a H(1)C(2) to H(1)C(3) and H(1)C(2) to H(1)C(3) coupling constant of 2.8 Hz. Computer spectral simulation and Karplus equation analysis are utilized to illustrate a relaxation of the torsion angles between H(1)C(2) and H(1)C(3), and H(1)C(2) and H(1)C(3) is solution.     

Crystal structure of [Yb(L(NO3)2(H2O)2](NO3), L = bromo-N,N,N′,N′-tetraethylmalonamide

[Yb(L(NO₃)₂(H₂O)₂](NO₃), L = bromo-N,N,N,N-tetraethylmalonamide crystallizes in the triclinic spacegroup P-1 with cell dimensions a = 9.030(9), b = 12.036(12), c = 12.392(13) Å, = 84.52(1), = 77.58(1), = 67.21(1)° , d_calc = 1.935 g cm^-3 for Z = 2. The ytterbium atom in the complex cation is nine-coordinate being bonded to two oxygen atoms from the malonamide ligand, two nitrate anions, and three water molecules.     

The chemistry of the “insoluble red woods.” Part 15. The crystal structures of 7-benzyloxy-6,2′,3′,4′-tetramethoxy- and 2,6,7,2′,3′,4′-hexamethoxy-isoflav-3-ene

The reaction of 7-benzyloxy-6,2,3,4-tetramethoxyisoflavylium perchlorate with 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)-prop-l-ene and of 6,7,2,3,4-pentamethoxyisoflavylium perchlorate with the same propene yielded respectively 7-benzyloxy-6,2,3,4-tetramethoxyisoflav-3-ene (5) and 2,6,7,2,3,4-hexamethoxyisoflav-3-ene (7) whose structures have been established by X-ray crystallography. Crystals of (5) are monoclinic, space groupP2₁/a (No. 14) with four molecules in a unit cell of dimensionsa=8.528(2),b=13.294(3),c=19.629(4) Å,=99.92(2)°. Crystals of (7) are also monoclinic, space groupC2/c (No. 15) with eight molecules in a unit cell of dimensionsa=28.088(3),b=10.662(3),c=12.869(1) Å,=97.32(1)°. Both structures were solved by direct methods and refined by full-matrix least-squares calculations to finalR values of 0.053 and 0.041 for 1673 and 1424 observed data for (5) and (7) respectively. The molecular dimensions are in accord with accepted values.For Part 14 see Whalley, W. B., Ferguson, G., and Khan, M. A., (1980)J. Chem. Res. (M), 2219.     

A comparative study on structure and conformation of three hydroxybenzylamine ligands

Structure and conformation of three tridentate ligands are determined. All these three compounds crystallize in different space groups, the details are as follows: Bis[(3,5-dimethyl,2-hydroxy)-2-hydroxy-5-methoxy]benzylcyclohexylamine (DHBC): monoclinic I2/a (a = 17.691(1) Å, b = 9.707(1) Å, c = 24.235(2) Å, = 91.028(1)°); bis[(3,5-dimethyl,2-hydroxy)-2-hydroxy-5-bromo]benzylcyclohexylamine (DHBrBC): tetragonal P4₁2₁2 (a = b = 12.1138(1) Å, c = 28.485(1) Å) and bis[(3,5-dimethyl,2-hydroxy)-2-hydroxy-5-bromo]benzylmethylamine (DHBrBM): triclinic (a = 5.228(1), b = 12.364(1) Å, c = 13.234(1) Å, = 94.04(1)°, = 95.72(1),° = 95.90(1)°). The cyclohexane rings in DHBC and DHBrBC assume chair conformation. Both the phenyl rings are planar in all the molecules and orient at angles of 75.5(1)°, 62.2(1)°, and 53.9(2)°, respectively with each other. The bond angles around N atom show the sp³ character. Inter- and intramolecular O–HN and O–HO types of hydrogen bondings stabilize the molecules in the unit cell in addition to van der Waals forces.     

Purported “melamine cyanuric acid trihydrochloride” C3H6N6⋅C3H3N3O3⋅3HCl is actually “diprotonated-melamine cyanuric acid dichloride dihydrate” (C3H8N6)2+⋅C3H3N3O3⋅2Cl−⋅2H2O

On the basis of the published results, melamine cyanuric acid trihydrochloride (MCA3HCl) is shown to be better described as diprotonated melamine cyanuric acid dichloride dihydrate (C₃H₈N₆)²⁺C₃H₃N₃O₃2Cl^–2H₂O. Details are given of the revised hydrogen bonding scheme, which requires further elaboration.     

Structure of bis(2-amino-5-methylpyridinium) tetrachlorozincate at 298 and 150 K

Reaction of 2-amino-5-methylpyridine with zinc chloride and HCl in aqueous solution yields bis(2-amino-5-methylpyridinium) tetrachlorozincate. The complex crystallizes in the monoclinic space group P2₁/c, with minimal tetrahedral distortion of the ZnCl₄ ^2– ion at both 298 and 150 K; at 298 K, a = 8.090(2) Å, b = 14.795(6) Å, c = 15.850(4) Å, = 101.93 (2); at 150 K, a = 8.0986(2) Å, b = 14.7190(5) Å, c = 15.7684(7) Å, = 102.862(2). The anisotropic cell contraction results in significant changes in nonbonding Cl Cl contacts.     

The molecular conformation of clonidine hydrochloride,an α-adrenergic agonist

The molecular conformation of the antihypertensive drug clonidine hydrochloride [2-(2,6-dichlorophenylimino)-2-imidazole HCl] has been shown by crystallographic studies to have a nearly perpendicular arrangement of the phenyl and imidazole rings as described by the torsion angles C₂-C₁-N₁-C₂= 76 ° and C₁-N₁-C₂-N₁ = 0 °. This conformation is not either of those suggested as the minimum energy form by CNDO/2 calculations for the protonated or free-base models. However, it is consistent with a nonplanar model proposed as the active conformer based on QSAR and spectral studies. The bonding about the imidazole carbon is similar to the guanidinium ion and the three C₂-N distances of the planar imidazole ring are nearly equal. The chloride ion forms strong hydrogen bonds with the amine hydrogen (2.3 Å) and the imidazole (N₁,) hydrogen (2.4 Å). Comparison with -adrenergic agonists shows that this conformation of clonidine fits the proposed pharmacophore model and should compete effectively for the -adrenergic receptors.Presented in part at the American Crystallographic Association Meeting, Clemson, South Carolina, January 1976.     

Synthesis and crystal structure of 1D 2,3-naphtho 15-crown-5 complex [Na(N15C5)]<Subscript>2</Subscript>[Ni(i-mnt)<Subscript>2</Subscript>] containing S⋅<Emphasis Type="Italic">s</Emphasis>C and S⋅<Emphasis Type="Italic">s</Emphasis>π interactions

The reaction of 2,3-naphtho-15-crown-5 (N15C5) with Na₂[Ni(i-mnt)₂] [i-mn = 1,1-dicyanoethylene-2,2-dithiolate] affords the title complex [Na(N15C5)]₂[Ni(i-mnt)₂] (1), which is characterized by elemental analysis, FT-IR, UV-visible spectra and single crystal X-ray diffraction. 1 crystallizes in the triclinic, space group P with a = 8.291(4), b = 12.833(7), c = 12.913(6) Å, = 115.732 (7), = 105.030(7), = 90.912(8), V = 1182.2(10) ų, Z = 1 and R₁(wR₂) = 0.0422(0.1001). The single crystal X-ray analysis shows that the [Na(N15C5)]⁺ complex cations act as the bridges linking the [Ni(i-mnt)₂]^2– anions into a 1D infinite chain through Na–N interactions and SsC and Ss interactions are observed in the chain with the shortest SsC distance of 3.433 Å.     

The photochemical reactivity of bis(tert-butylcyclopentadienyl)molybdenum dihydride: synthesis and structure of dinuclear trans-[(CpBu t)Mo(μ-σ,η 5-C5H3But)H]2

Photolysis of (Cp^{Bu t})₂MoH₂ in benzene yields the molybdenocene derivative trans-[(Cp^{Bu t})Mo(- ,⁵-C₅H₃Bu^t)H]₂. An X-ray diffraction study demonstrate that the molybdenum centers of trans-[(Cp^{Bu t})Mo(- , ⁵-C₅H₃Bu^t)H]₂ are bridged by two , ⁵-C₅H₃Bu^t ligands, each one of which coordinates in a -manner to one molybdenum center and an ⁵-manner to the other, thereby resulting in a centrosymmetric dimer with a structural type that is different from that of [CpMo(- , ⁵-C₅H₄)]₂ which possesses a Mo–Mo bond.     

Low-temperature,high-resolution crystal structure study of tricyclo[3.3.1.13,7]decan-2-ol (adamantanol-2)

The structure of the title compound (C₁₀H₁₅OH) was determined by X-ray diffraction at liquid nitrogen temperature. The crystals are triclinic, spacegroupP¯1 witha=11.3686(5),b=11.3990(5),c=11.4353(6) Å,=82.193(4),=70.211(4) and =62.279(4)°,V _c =1233.9(1) ų,Z=6,F(000)=504,D _x =1.229 g cm^–3; MoK radiation, =0.71073 Å,(MoK)=0.7 cm^–1. FinalR factor=0.046 andwR=0.062 for 8162 reflections withI>2.5(I). The asymmetric unit consists of three independent adamantanol-2 molecules which together with the three symmetry-related molecules form a cluster having pseudo ¯3 symmetry. The six molecules in the cluster are connected by six O-HO hydrogen bonds, the oxygens of which constitute an almost ideal chair conformation.