scholarly journals Withanolides from Physalis angulata L.

Author(s):  
R. Ya. Okmanov ◽  
M. M. Makhmudova ◽  
I. D. Bobaev ◽  
B. Tashkhodjaev

The compounds (17S,20R,22R,24R,25S)-5β,6β:20,24-diepoxy-4β,25-dihydroxy-1-oxowith-2-en-26,22-olide and (20R,22R)-5α,14α,20-Trihydroxy-1-oxo-6α,7α-epoxywitha-2-enolide were isolated from a chloroform extract of the aerial parts of Physalis angulata L. (Solanaceae). Two products were isolated from the chromatographic separation extract. Compound I corresponds to physangulide B chloroform monosolvate, C28H38O7·CHCl3, while compound II is 14α-hydroxyixocarpanolide, C28H40O7. In the two molecular structures, the conformation of the steroid part (rings A, B, C, D) does not differ. In both crystals, molecules are linked by intermolecular O—H...O hydrogen bonds along the c-axis direction and form a two-dimensional network parallel to the ac plane. The absolute configuration was determined from X-ray diffraction data.

2010 ◽  
Vol 65 (12) ◽  
pp. 1462-1466 ◽  
Author(s):  
Michaela K. Meyer ◽  
Jürgen Graf ◽  
Guido J. Reiß

[Me(HO)2P-(CH2)10-P(O)OHMe]2[I3]2・MeHO(O)P-(CH2)10-P(O)OHMe (1) was synthesized and characterized by IR, Raman and NMR spectroscopy. Its structure was determined by singlecrystal X-ray diffraction (T = 100 K; space group P1̄). The structure consists of decane-1,10-diyl-bis- (methylphosphinic acid) molecules and the analogous mono-protonated cations in a ratio 1:2 connected with each other by strong O-H···O hydrogen bonds to form a two-dimensional network. Between these hydrogen-bonded layers, there are elongated cavities each containing two triiodide anions. The intermolecular I· · · I distance of the two enclosed triiodide anions is 3.6317(4) Å and should be considered as an interhalogen bonding interaction.


2011 ◽  
Vol 66 (5) ◽  
pp. 459-464 ◽  
Author(s):  
Chao Xu ◽  
Sheng-Bo Liu ◽  
Taike Duan ◽  
Qun Chen ◽  
Qian-Feng Zhang

Two novel cadmium coordination polymers, [Cd(pydc)2(tu)]n (1) and [Cd2(SO4)(nic)2(tu)1.5 - (H2O)2]n (2) (pydc = pyridine-2,3-dicarboxylate, nic = nicotinate, tu = thiourea), have been synthesized under hydrothermal conditions and structurally characterized by X-ray diffraction analysis. 1 is a one-dimensional ladder coordination polymer in a two-dimensional network formed by hydrogen bonds. 2 consists of two kinds of Cd(II) centers in different coordination environments connected via nicotinate and sulfate to form a two-dimensional grid network integrated in a three-dimensional framework generated by hydrogen bonds. 2 shows intense fluorescent emission in the solid state at room temperature


2007 ◽  
Vol 62 (10) ◽  
pp. 1271-1276 ◽  
Author(s):  
Liang Chen ◽  
Xian-Wen Wanga ◽  
Jing-Zhong Chen ◽  
Jian-Hong Liu

The complexes Mn(Cl3CCOO)2(4,4′-bpy) (1) and [Cu2(ClCH2COO)(2,2′-bpy)2(OH)(H2O)]-(NO3)2(2) (bpy = bipyridine) were generated under mild reaction conditions and characterized by IR spectra, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and single crystal X-ray diffraction. Compound 1 exhibits a two-dimensional network with octahedrally coordinated Mn(II) atoms linked by 4,4′-bpy ligands and Cl3COO− ligands. Compound 2 features a supramolecular structure of binuclear complexes, with edge-sharing five-coordinated square-pyramidal units bridged by the ClCH2COO− ligand, an OH− group and a water molecule. Complex 1 crystallizes in the orthorhombic space group Pbcn with cell parameters: a = 16.5390(17), b = 11.6396(17), c = 9.9181(12) Å, V = 1909.3(4) Å3, Z = 4, wR2 = 0.1576. Complex 2 crystallizes in the triclinic space group P1̅ with cell parameters: a = 7.6190(15), b = 11.151(2), c = 16.640(3) Å , α = 73.13(3), β = 80.89(3), γ = 74.51(3)°, V = 1298.73(4) Å3, Z = 2, wR2 = 0.1265.


Author(s):  
Kai-Long Zhong

A new one-dimensional NiIIcoordination polymer of 1,3,5-tris(imidazol-1-ylmethyl)benzene, namelycatena-poly[[aqua(sulfato-κO)hemi(μ-ethane-1,2-diol-κ2O:O′)[μ3-1,3,5-tris(1H-imidazol-1-ylmethyl)benzene-κ3N3,N3′,N3′′]nickel(II)] ethane-1,2-diol monosolvate monohydrate], {[Ni(SO4)(C18H18N6)(C2H6O2)0.5(H2O)]·C2H6O2·H2O}n, was synthesized and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The NiIIcation is coordinated by three N atoms of three different 1,3,5-tris(imidazol-1-ylmethyl)benzene ligands, one O atom of an ethane-1,2-diol molecule, by a sulfate anion and a water molecule, forming a distorted octahedral NiN3O3coordination geometry. The tripodal 1,3,5-tris(imidazol-1-ylmethyl)benzene ligands link the NiIIcations, generating metal–organic chains running along the [100] direction. Adjacent chains are further connected by O—H...O hydrogen bonds, resulting in a two-dimensional supermolecular architecture running parallel to the (001) plane. Another water molecule and a second ethane-1,2-diol molecule are non-coordinating and are linked to the coordinating sulfate ionsviaO—H...O hydrogen bonds.


2020 ◽  
Vol 76 (11) ◽  
pp. 1024-1033
Author(s):  
Fang-Hua Zhao ◽  
Shi-Yao Li ◽  
Wen-Yu Guo ◽  
Zi-Hao Zhao ◽  
Xiao-Wen Guo ◽  
...  

Two new CdII MOFs, namely, two-dimensional (2D) poly[[[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ2-heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C7H10O4)(C18H18N4)]·4H2O} n or {[Cd(Pim)(bbimb)]·4H2O} n (1), and 2D poly[diaqua[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ4-decanedioato)(μ2-decanedioato)dicadmium(II)], [Cd2(C10H16O4)2(C18H18N4)(H2O)2] n or [Cd(Seb)(bbimb)0.5(H2O)] n (2), have been synthesized hydrothermally based on the 1,4-bis(1H-benzimidazol-1-yl)butane (bbimb) and pimelate (Pim2−, heptanedioate) or sebacate (Seb2−, decanedioate) ligands. Both MOFs were structurally characterized by single-crystal X-ray diffraction. In 1, the CdII centres are connected by bbimb and Pim2− ligands to generate a 2D sql layer structure with an octameric (H2O)8 water cluster. The 2D layers are further connected by O—H...O hydrogen bonds, resulting in a three-dimensional (3D) supramolecular structure. In 2, the CdII centres are coordinated by Seb2− ligands to form binuclear Cd2 units which are linked by bbimb and Seb2− ligands into a 2D hxl layer. The 2D layers are further connected by O—H...O hydrogen bonds, leading to an 8-connected 3D hex supramolecular network. IR and UV–Vis spectroscopy, thermogravimetric analysis and solid-state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe3+ in aqueous solution.


Author(s):  
Mwaffak Rukiah ◽  
Thaer Assaad

The title two-dimensional coordination polymer, [Na(C2H8NO6P2)]n, was characterized using powder X-ray diffraction data and its structure refined using the Rietveld method. The asymmetric unit contains one Na+cation and one (1-azaniumylethane-1,1-diyl)bis(hydrogen phosphonate) anion. The central Na+cation exhibits distorted octahedral coordination geometry involving two deprotonated O atoms, two hydroxy O atoms and two double-bonded O atoms of the bisphosphonate anion. Pairs of sodium-centred octahedra share edges and the pairs are in turn connected to each other by the biphosphonate anion to form a two-dimensional network parallel to the (001) plane. The polymeric layers are connected by strong O—H...O hydrogen bonding between the hydroxy group and one of the free O atoms of the bisphosphonate anion to generate a three-dimensional network. Further stabilization of the crystal structure is achived by N—H...O and O—H...O hydrogen bonding.<!?tpb=18.7pt>


2020 ◽  
Vol 76 (7) ◽  
pp. 1096-1100
Author(s):  
Theerachart Leepasert ◽  
Patchreenart Saparpakorn ◽  
Kittipong Chainok ◽  
Tanwawan Duangthongyou

The crystal structure of the natural product zeylenone, C21H18O7, was confirmed by single-crystal X-ray diffraction. The crystal structure has three chiral centers at positions C1, C5 and C6 of the cyclohexanone ring, but the absolute configuration could not be determined reliably. The methyl benzoate and benzoyloxy substituents at positions C1 and C5 of the cyclohexenone ring are on the same side of the ring with the dihedral angle between their mean planes being 16.25 (10)°. These rings are almost perpendicular to the cyclohexenone ring. The benzoate groups and two hydroxyl groups on the cyclohexenone ring form strong hydrogen bonds to consolidate the crystal structure. In addition, weak C—H...O hydrogen bonds also contribute to the packing of the structure.


2018 ◽  
Vol 74 (11) ◽  
pp. 1267-1273
Author(s):  
Shuai He ◽  
Ying Xin ◽  
Jiansheng Li ◽  
Zaiming Zhu ◽  
Peng Zhao ◽  
...  

A novel complex based on the Dawson-like [H3BiW18O60]6−, i.e. (C2H9N2)2[{Cu(C10H8N2)(C2H8N2)}2(H3BiW18O60)]·5.5H2O or (enH)2[{Cu(2,2′-bipy)(en)}2(μ4-H3BiW18O60)]·5.5H2O, (1), where enH is protonated ethane-1,2-diamine, 2,2′-bipy is 2,2′-bipyridine and en is ethane-1,2-diamine, has been synthesized hydrothermally and characterized by elemental analysis, single-crystal X-ray diffraction analysis, IR spectroscopy, powder XRD, and thermogravimetry and differential thermal analysis (TG–DTA). For (1), each [H3BiW18O60]6− anion acts as a tetradentate ligand connecting [Cu(2,2′-bipy)(en)]2+ fragments via two terminal and two bridging O atoms, forming a two-dimensional network structure. Along the a and c axes, polyoxometalate units are arranged in an AB…AB manner. The electrochemical behaviour of (1)–CPE (CPE is a carbon paste electrode) was investigated in 2 M H2SO4 solution by cyclic voltammetry (CV). The redox process of WVI/V takes place at E 1/2 = −0.58 (I–I′) and −0.37 V (II–II′), and at −0.04 V (III–III′) for CuII/0. The magnetic properties of (1) were investigated in the range 2–300 K and indicated the existence of strong antiferromagnetic exchange interactions between the Cu2+ centres.


2019 ◽  
Vol 75 (8) ◽  
pp. 1065-1072 ◽  
Author(s):  
Zhi-Chao Shao ◽  
Xiang-Ru Meng ◽  
Hong-Wei Hou

Aminobenzoic acid derivatives are widely used in the preparation of new coordination polymers since they contain O-atom donors, as well as N-atom donors, and have a rich variety of coordination modes which can lead to polymers with intriguing structures and interesting properties. Two new coordination polymers incorporating 1-aminobenzene-3,4,5-tricarboxylic acid (H3abtc), namely, poly[(μ3-1-amino-5-carboxybenzene-3,4-dicarboxylato)diaquacadmium(II)], [Cd(C9H5NO6)(H2O)2] n , (I), and poly[[bis(μ5-1-aminobenzene-3,4,5-tricarboxylato)triaquatrizinc(II)] dihydrate], {[Zn3(C9H4NO6)2(H2O)3]·2H2O} n , (II), have been prepared and structurally characterized by single-crystal X-ray diffraction. In polymer (I), each tridentate 1-amino-5-carboxybenzene-3,4-dicarboxylate (Habtc2−) ligand coordinates to three CdII ions to form a two-dimensional network structure, in which all of the CdII ions and Habtc2− ligands are equivalent, respectively. Polymer (II) also exhibits a two-dimensional network structure, in which three crystallographically independent ZnII ions are bridged by two crystallographically independent pentadentate 1-aminobenzene-3,4,5-tricarboxylate (abtc3−) ligands. This indicates that changing the metal ion can influence the coordination mode of the H3abtc-derived ligand and further influence the detailed architecture of the polymer. Moreover, the IR spectra, thermogravimetric analyses and fluorescence properties were investigated.


2004 ◽  
Vol 59 (6) ◽  
pp. 661-672 ◽  
Author(s):  
Virginia Lozano ◽  
Oliver Moers ◽  
Peter G. Jones ◽  
Armand Blaschette

Two crystal structures (polymorphs) of di(4-bromobenzenesulfonyl)amine (1), as determined by low-temperature single-crystal X-ray diffraction, are reported: Form A, monoclinic, P21/c, Z' = 1; form B: monoclinic, P21/c, Z' = 2. In A, the molecule adopts an extended conformation approximating to C2 symmetry, whereas the two independent molecules of form B display a folded hair-pin conformation with pseudo-mirror symmetry [torsion τ (C-S···S’-C’) and intercentroid distance dIC of the aromatic rings in A: 173.2° and 750.8 pm, in B: −5.4/−8.90° and 364.1/366.5 pm]. The packings of both polymorphs consist of layers, in which the molecules are connected by N-H···O hydrogen bonds in one and by Br···O interactions in the other dimension. The 1:1 onium salt (2; monoclinic, P21/n, Z' = 1) produced on N-deprotonation of 1 with 2,4-dimethylpyridine is structurally related to B. Its packing involves strands of formula units, whereby the anions retain the folded conformation (τ = 5.8°, dIC = 372.5 pm) and perfectly mimic the catemeric Br···O pattern of B, while the cations are isotactically connected to the anion backbone via an N-H(···O)2 three-centre bond. In all structures, a three-dimensional network of weak hydrogen bonds C-H···A (A = O, in 2 also N−) and C-H···Br contacts supports the controlling N-H···O and Br···O interactions; moreover, an intermolecular (π···π) stacking dimer of the type phenyl/phenyl and a (π···π) stacking trimer of the type phenyl/pyridinium/phenyl have been identified in A and 2, respectively. None of the structures exhibits very short bromine-bromine contacts suggestive of specific attractive forces.


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