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1.
Galactomannan (yield 1.73% of seed mass) with molecular weight 808 kDa was isolated from seeds of Gueldenstaedtia monophylla Fisch. (Fabaceae). Its solutions were typically highly viscous with [η] 664.7 mL/g and optically active with [α]D +45.2°. It consisted of galactose and mannose in a 1:1.91 ratio. Physical chemical methods established that the principal
chain of the polysaccharide consisted of 1,4-β-D-mannopyranose units substituted 50.1% in the C-6-position by single α-D-galactopyranose units and traces of 6-O-α-galactopyranosylgalactopyranose. The contents of mannobiose blocks substituted by galactose Man–Man, (Gal)Man–Man/Man–Man(Gal),
and (Gal)Man–Man(Gal) in the galactomannan macromolecule were 23, 42, and 35%, respectively. 相似文献
2.
Galactomannans with galactose:mannose ratios 1:1.48 and 1:1.33, [α]D +67.9 and +76.4°, [η] 870.3 and 1337.1 mL/g, and molecular weights 999 and 1549 kDa, respectively, were isolated in 0.59
and 4.65% yields (of seed mass) from seeds of Astragalus alpinus and A. tibetanus (Fabaceae). Physicochemical methods (CrO3 oxidation; methylation–GC/MS; IR, NMR, and 13C spectroscopy) found that the main polysaccharide chain consisted of 1,4-β-D-mannopyranose units substituted 67.5% (A. alpinus) and 75.2% (A. tibetanus) at the C-6 position by single α -D-galactopyranose units. The contents of mannobiose blocks Man–Man, (Gal)Man–Man/Man–Man(Gal), and (Gal)Man–Man(Gal) variously
substituted with galactose were according to 13C NMR spectroscopy 15.9, 55.5, and 28.6% in A. alpinus galactomannan and 9.9, 42.3, and 47.8% in A. tibetanus galactomannan. 相似文献
3.
Galactomannan (yield 3.58% of seed mass) of molecular weight 876 kDa was isolated from seeds of Astragalus sericeocanus Gontsch. (Fabaceae). Its solutions had high viscosity [η], 764.6 mL/g, and optical density [α]D +65.3°. The polysaccharide consisted of galactose and mannose in molar ratio 1:1.58. The main chain of the galactomannan
macromolecule was constructed of 1,4-β-D-mannopyranose units, 63% of which were substituted at C-6 by single α-D-galactopyranose units. 13C NMR spectroscopy established that the galactomannan contained units of differently substituted galactose mannobiose units:
Man-Man, (Gal)Man-Man, and/or Man-Man(Gal) in addition to (Gal)Man-Man(Gal), the ratio of which was 0.15:0.51:0.34.
Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 555–557, November–December, 2008. 相似文献
4.
Galactomannan of molecular weight 472 kDa was isolated from Astragalus danicus Retz. (Fabaceae) seeds and consisted of galactose and mannose units in a 1:1.40 molar ratio. The main chain of the macromolecule
was constructed of 1,4-β-D-mannopyranose units, 71% of which were substituted at C-6 by single α-D-galactopyranose units.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 255257, May-June, 2009. 相似文献
5.
Two new inorganic–organic hybrid compounds, namely [Cu(dab)2]2[α-SiW12O40]·H2O (dab = 1,2-diaminobenzene) and [Cu(dafo)3]2[Cu(dafo)2(H2O)2][α-PMo12O40]2·4H2O (dafo = 4,5-diaza- fluorene-9-one) have been synthesized under hydrothermal conditions and structurally characterized by
single-crystal X-ray diffraction. [Cu(dab)2]2[α-SiW12O40]·H2O exhibits an alternating 2D ladder-like structure built of [α-SiW12O40]4− and [Cu(L)2]2+ units. As the inorganic building block, the Keggin-type polyoxoanion [α-SiW12O40]4− is linked to two metal–organic complexes [Cu(dab)2]2+ through different kinds of oxygen atoms (terminal and bridging). [Cu(dafo)3]2[Cu(dafo)2(H2O)2][α-PMo12O40]2·4H2O shows an extended 3D supramolecular network via hydrogen bonding. Both complexes were characterized by physico-chemical
and spectroscopic methods. 相似文献
6.
Abstract Two novel organic–inorganic composite phosphotungstates, [H9{Ce(α-PW11O39)2}Cu(en)2] · 6H2O (1) and H7[Cu(en)2{Er(α-PW11O39)2}Cu(en)2] · 12H2O (2) (en = ethylenediamine) have been synthesized by the hydrothermal reaction of the trivacant Keggin polyoxoanion [α-A-PW9O34]9− with CeIII or ErIII ions in the presence of Cu2+ ions and en, and structurally characterized by IR spectra, elemental analysis and thermogravimetric analysis. X-ray crystallographic
analyses indicate that they are all built by sandwich-type [Ln(α-PW11O39)2]11− (Ln = CeIII, ErIII) polyoxoanions and [Cu(en)2]2+ cations generating infinite one-dimensional arrangements. To our knowledge, this 1-D chain structures constituted by mono-Ln
sandwiched POM units and transition-metal complex cations are very rare.
Graphical Abstract Two novel organic–inorganic composite phosphotungstates, [H9{Ce(α-PW11O39)2}Cu(en)2] · 6H2O (1) and H7[Cu(en)2{Er(α-PW11O39)2}Cu(en)2] · 12H2O (2) (en = ethylenediamine) have been synthesized by the hydrothermal reaction of the trivacant Keggin polyoxoanion [α-A-PW9O34]9− with CeIII or ErIII ions in the presence of Cu2+ ions and en, and structurally characterized by IR spectra, elemental analysis and thermogravimetric analysis. X-ray crystallographic
analyses indicate that they are all built by sandwich-type [Ln(α-PW11O39)2]11− (Ln = CeIII, ErIII) polyoxoanions and [Cu(en)2]2+ cations generating infinite one-dimensional arrangements. To our knowledge, this 1-D chain structures constituted by mono-Ln
sandwiched POM units and transition-metal complex cations are very rare.
相似文献
7.
M. R. Mirzaeva R. K. Rakhmanberdyeva D. A. Rakhimov 《Chemistry of Natural Compounds》1999,35(5):505-507
The structure of galactomannan from seeds ofGleditsia macracantha is studied by methylation, periodate oxidation, and partial acid hydrolysis. The principal polyglycoside chain consists of
β-1→4-bonded mannopyranose units, where the mannose is substituted in the 6-position by single α-D-galactopyranose units.
Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 573–576, September–October, 1999. 相似文献
8.
K. Ramalingam R. Thiruneelakandan G. Bocelli L. Righi 《Transition Metal Chemistry》2012,37(3):265-270
The complexes trans-[Ni(4-MP)2(NCS)2]·MeCN (1) and trans-[Ni(3-MP)2(NCS)2] (2) (4-MP = tri(4-methylphenyl)phosphine, 3-MP = tri(3-methylphenyl)phosphine) were prepared and characterized by IR, UV–visible,
NMR spectra, CV, TGA and single crystal X-ray crystallography. Both the complexes have planar geometry and are diamagnetic.
The Ni–P distances in both complexes are relatively short as a result of strong back donation from nickel to phosphorus. The
phenyl rings in the 3-MP analogue (2) show increased pitching with reference to the plane formed by the ipso carbons due to increased steric effects. For complex
(2), the N–Ni–N and P–Ni–P angles are significantly lower than the almost linear N–Ni–N and N–Ni–P angles observed for both
complex (1) and trans-[Ni(PPh3)2(NCS)2]. This observation indicates that the 3-methylphosphine ligand forces complex (2) to distort towards a tetrahedral geometry. IR spectra of both complexes show strong bands around 2,090 cm−1 due to N-coordinated thiocyanate, while the electronic spectra contain d–d transitions around 452 nm. Cyclic voltammograms
show that the irreversible one-electron reduction potentials increase in the following order: trans- [Ni(PPh3)2(NCS)2] < trans- [Ni(3-MP)2(NCS)2] < trans-[Ni(4-MP)2(NCS)2], revealing the electron releasing effect of the methyl groups. The planar complexes exhibit interallogony in coordinating
solvents. 相似文献
9.
Acetate-Functionalized Zirconium-Substituted Tungstogermanate, [Zr4O2(OH)2(CH3COO)2(α-GeW10O37)2]12−
Lili Chen Ying Liu Shuanhu Chen Huaiming Hu Feng Fu Jiwu Wang Ganglin Xue 《Journal of Cluster Science》2009,20(2):331-340
The two acetate-functionalized zirconium(IV)-substituted tungstogermanates, Na8K4[Zr4O2(OH)2(CH3COO)2(α-GeW10O37)2] · 33H2O and Na8Cs4[Zr4O2(OH)2(CH3COO)2(α-GeW10O37)2] · 32H2O, were synthesized by the reaction of ZrOCl2 with [A-α-GeW9O34]10− in pH = 4.8 buffer and their structures were determined by single-crystal X-ray analysis. Both of them contain a centrosymmetric
polyanion [Zr4O2(OH)2(CH3COO)2(α-GeW10O37)2]12− consisting of two {α-GeW10O37} units sandwiching an inorganic–organic hybrid {Zr4O2(OH)2(CH3COO)2} cluster. The polyanion contains a mixing of seven- and eight-coordinate Zr centres. The two compounds were also characterized
by elemental analysis, IR spectroscopy, UV–vis and TG–DSC analysis. 相似文献
10.
Abstract Two novel inorganic–organic hybrid sandwich-type phosphotungstates [H2en][Ni(en)2]2[{(α-B-PW9O34)2Ni4(H2O)2}{Ni(en)2(H2O)}2] · 5H2O (1) and [Ni(en)2][Ni(en)2(H2O)2][{(α-B-PW9O34)2Ni4(Hen)2}{Ni(en)2(H2O)}2] · 10H2O (2) (en = ethylenediamine) have been synthesized by the hydrothermal reactions of trivacant precursors Na9[α-A-PW9O34] · 7H2O/Na12[α-P2W15O56] · 18H2O with NiCl2 · 6H2O in the presence of en and structurally characterized by IR spectra, elemental analyses and thermogravimetric analyses. X-ray
crystallographic analyses indicate that 1 is made up of inorganic polyoxoanions [Ni4(H2O)2(α-B-PW9O34)2]10– decorated by nickel-organoamine groups, while 2 is constructed from inorganic–organic hybrid polyoxoanions [(α-B-PW9O34)2Ni4(Hen)2]8– decorated by nickel-organoamine groups.
Graphical Abstract
Hydrothermal Synthesis and Structural Characterization of Two Organic–Inorganic Hybrids based on Sandwich-type Polyoxometalates
Bing Li, Zhao Dan, Shou-Tian Zheng, Guo-Yu Yang
相似文献
11.
Y. Liu D. Y. Shi J. W. Zhao X. Y. Wang H. L. Cheng L. J. Chen P. T. Ma J. Y. Niu 《Russian Journal of Coordination Chemistry》2011,37(9):712-717
A novel 2D organic-inorganic hybrid 3d–4f polyoxometalate [Cu(Dap)2(H2O)][Cu(Dap)2]4.5[Gd(α-PW11O39)2] · 5H2O (I) (Dap = 1,2-diaminopropane) built by [Gd(α-PW11O39)2]11− units and [Cu(Dap)2]2+ bridges has been synthesized hydrothermally by the reaction of GdCl3, CuCl2 · 2H2O, Na9[A-α-PW9O34] · 7H2O, and Dap and characterized by elemental analysis, IR spectrum, UV spectrum, powder X-ray diffraction, and single-crystal
X-ray diffraction. Single-crystal structural analysis shows that I displays an interesting 2D 3d–4f heterometallic sheet architecture with a 5-connected topology constructed from 1: 2-type [Gd(α-PW11O39)2]11− subunits and [Cu(Dap)2]2+ bridges. To the best of our knowledge, I represents a rare organic-inorganic hybrid 2D 3d–4f heterometallic monovacant Keggin phosphotungstate. 相似文献
12.
Pectinic substances were isolated in 3.82% yield of the fresh material mass from leaves of Aloe arborescens Mill. (Asphodelaceae). Fractionation over DEAE-cellulose produced the dominant polymer APS-3 of molecular weight
71.1 kDa, [α]D20 +224.4°. Physicochemical methods established that APS-3 was a partially methoxylated and acetylated rhamnopolygalacturonan
consisting of α-(1→4)-bonded galacturonic acid and α-(1→2)-bonded rhamnopyranose in the main chain. Side substituents of single
galacto- and glucopyranose units were located on the C-3 atom of galacturonic acid. 相似文献
13.
Yuanyuan Cong Rena Kasimu Hui Dai Palida Abulizi Ping Sheng Xiaoming Gao Pengfei Tu 《Chemistry of Natural Compounds》2009,45(1):11-13
A neutral polysaccharide Gi-A1 was isolated from the roots of Glycyrrhiza inflata Bat. It had a molecular mass of over 2000 kDa
and showed [α]D20 + 81.4° (c 1.05, H2O). Acid hydrolysis and methylation analysis indicated that Gi-A1 was mainly composed of α-D-glucose, α-L-arabinose, and α-D-galactose
with a molar ratio of 8.0:1.8:1.0. It can significantly stimulate spleen cell proliferation in vitro (P < 0.01).
Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 13–14, January–February, 2009. 相似文献
14.
Xiao-Lan Wang Ying Lu Jing-Xin Meng En-Bo Wang Hai Fu 《Transition Metal Chemistry》2011,36(2):201-206
Three new organic–inorganic hybrid complexes based on the Wells–Dawson polyoxoanion, namely (H2bpp)[Ni2(bpp)2(H2O)4(P2W18O62)]·H2O 1, [Cu6(Hbpy)6(bpy)3(P2W18O62)2]·2H2O 2 and (Him)5[Cu(im)2(P2W18O62)]·4H2O 3 [bpp = 1,3-bis (4-pyridyl) propane, bpy = 4,4′-bipyridine, im = imidazole] have been synthesized and characterized. Complex
1 exhibits a three-dimensional (6, 3)-connected framework with anatase topology constructed from [α-P2W18O62]6− clusters and [Ni(bpp)]2+ fragments. Each [α-P2W18O62]6− anion links to six nickel atoms through six terminal oxygen atoms from four polar and two equatorial WO6 octahedra, which shows a novel coordination mode of a Wells–Dawson cluster with a transition-metal atom. Complex 2 displays an interesting one-dimensional double-chain structure built from [α-P2W18O62]6− clusters and [Cu2(bpy)(Hbpy)2]2+ fragments. To our knowledge, complex 2 represents the first double-chain organic–inorganic hybrid complex based on a Wells–Dawson-type cluster. Complex 3 possesses a one-dimensional zigzag chain structure constructed from [α-P2W18O62]6− anions and [Cu(im)2]+ units through weak Cu···O interactions. 相似文献
15.
Carmen Batista José Daniel Martínez Mary Lorena Araujo Felipe Brito Giuseppe Lubes Mildred Rodríguez Vito Lubes 《Journal of solution chemistry》2011,40(6):944-954
In this paper we present speciation results for the ternary vanadium(III)–dipicolinic acid (H2dipic) systems with the amino acids glycine (Hgly), proline (Hpro), α-alanine (Hα-ala), and β-alanine (Hβ-ala), obtained by means of electromotive forces measurements emf(H) using 3.0 mol⋅dm−3 KCl as the ionic medium and a temperature of 25 °C. The experimental data were analyzed by means of the computational least-squares
program LETAGROP, taking into account hydrolysis of the vanadium(III) cation, the respective stability constants of the binary
complexes, and the acid base reactions of the ligands, which were kept fixed during the analysis. In the vanadium(III)–dipicolinic
acid–glycine system, formation of the ternary [V(Hdipic)(Hgly)]2+, [V(dipic)(Hgly)]+, [V(dipic)(gly)], [V(dipic)(gly)(OH)]− and [V(dipic)(gly)(OH)2]2− was observed; in the case of the vanadium(III)–dipicolinic acid–proline system the ternary complexes [V(Hdipic) (Hpro)]2+, [V(dipic)(Hpro)]+, [V(dipic)(pro)] and [V(dipic)(pro)(OH)]− were observed; in the vanadium(III)–picolinic acid–α-alanine were observed [V(Hdipic)(Hα-ala)]2+, [V(dipic) (Hα-ala)]+, [V(dipic)(αala)], [V(dipic)(α-ala)(OH)]− and [V(dipic)(α-ala)(OH)2]2−; and in the vanadium(III)–dipicolinic acid–β-ala system the complexes [V(dipic) (Hβ-ala)]+, [V(dipic)(β-ala)], [V(dipic)(β-ala)(OH)]− and [V(dipic)(β-ala)(OH)2]2− were observed. Their respective stability constants were determined, and we evaluated values of Δlog 10
K″ in order to understand the relative stability of the ternary complexes compared to the corresponding binary ones. The species
distribution diagrams are briefly discussed as a function of pH. 相似文献
16.
Jian-Long Xia Wei-Cheng Xiong Gang Chen Guang-Ao Yu Shan Jin Sheng-Hua Liu 《Transition Metal Chemistry》2009,34(4):389-393
Abstract Formal [2 + 2 + 2] addition reaction of [Cp*Ru(H2O)(NBD)][BF4] (NBD = norbornadiene) with 4,4′-Diethynylbiphenyl generates [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2. The reaction of [Cp*Ru(H2O)(NBD)][BF4] with 1,4-diphenylbutadiyne generates the unusual [2 + 2 + 2] additional organic compound Ph–C≡C–C9H8–Ph in addition to the organometallic compound [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4]. [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BPh4]2 is generated after the reaction of compound [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2 with Na[BPh4]. The structure of this compound was confirmed by X-ray diffraction. A possible approach to form Ph–C≡C–C9H8–Ph and [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4] is suggested.
Graphical Abstract Formal [2 + 2 + 2] addition reaction of [Cp*Ru(H2O)(NBD)]BF4 (NBD = norbornadiene) with 4,4′-Diethynylbiphenyl generates [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2. The reaction of [Cp*Ru(H2O)(NBD)][BF4] with 1,4-diphenylbutadiyne simply generates unusual [2 + 2 + 2] additional organic compound Ph–C≡C–C9H8–Ph in addition to the organometallic compound [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4]. [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BPh4]2 is generated after the reaction of compound [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2 with Na[BPh4]. The structure of this compound was confirmed by X-ray diffraction. And the possible approach to form Ph–C≡C–C9H8–Ph and [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4] was suggested.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
M. N. Sokolov E. V. Chubarova E. V. Peresypkina A. V. Virovets V. P. Fedin 《Russian Chemical Bulletin》2007,56(2):220-224
The reactions of the tetranuclear hydroxo complexes [M4(μ2-OH)8(H2O)16]8+ (M = Zr or Hf) with the lacunary Keggin-type ([α-PW11O39]7−) and Dawson-type ([α 2-P2W17O61]10−) phosphotungstates in aqueous solutions produce the sandwich polyoxometalate complexes [M(α-PW11O39)2]10− (M = Zr (1) or Hf (2)) and [M(α 2-P2W17O61)2]16− (M = Zr (3) and Hf (4)). The complexes were isolated and structurally characterized as salts with potassium and dimethylammonium cations. The zirconium
and hafnium atoms have a square antiprismatic coordination environment (coordination number is 8). In all complexes, the mutual
arrangement of the ligands corresponds to the syn isomer. Hafnium complexes 2 and 4 are the first structurally characterized polyoxometalate complexes of this metal. The structures of the resulting compounds
were confirmed also by 31P NMR spectroscopy in solution.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 214–218, February, 2007. 相似文献
18.
Abstract
A new 2-D organic–inorganic hybrid Wells–Dawson-Type polyoxotungstate K[Cu(Im)2]6P2W18O62·2H2O·(OH) (Im = Imidazole) (1) has been synthesized under hydrothermal conditions and characterized by IR spectroscopy, TG, and single crystal X-ray structural analysis. Crystal data for 1: triclinic, P-1, a = 15.3676(12) ?, b = 15.5059(14) ?, c = 24.6437(19) ?, α = 98.088(2)°, β = 96.930(2)°, γ = 119.312(2)°, Z = 2. Single crystal X-ray structural analysis reveals that the [P2W18O62]6− polyoxoanion is linked by [Cu(Im)2]+ cation to form a 1-D chain along the a axis which is connected by K+ cation down the c axis to form a 2-D layer. 相似文献19.
Lancui Zhang Yi Zhao Wansheng You Zaiming Zhu Cuiying Huang 《Journal of Cluster Science》2010,21(2):93-103
Using Cu(II/I)/Ni(II) complex fragments and [Bu4N]4[α-Mo8O26] as precursors, four compounds based on α- or β- octamolybdate isomers, [{Cu(tpdoen)}2][α-Mo8O26]·3H2O 1 (tpdoen = 2-(pyridin-2-ylmethoxy)-N-(2-(pyridin-2-ylmethoxy)ethyl)-N-(pyridin-2-ylmethyl)ethanamine); [{Cu(dpoen)}2(α-Mo8O26)] 2 (dpoen = 2-(pyridin-2-ylmethoxy)-N-(pyridin-2-ylmethyl)ethanamine); [{Cu(dpmea)}2(β-Mo8O26)] 3 (dpmea = N,N-diethyl-N-(pyridin-2-ylmethyl)ethanaminium); [{Ni(tpoen)}2(β-Mo8O26)]·5H2O 4 (tpoen = 2-(pyridin-2-ylmethoxy)-N,N-bis(pyridin-2-ylmethyl)ethanamine) were hydrothermally synthesized. They have been characterized by elemental analysis, FT-IR,
TG analysis and single-crystal X-ray diffraction. Compound 1 is a discrete structure constructed from [α-Mo8O26]4− anions and [Cu(tpdoen)]2+ coordination cations. The coordination cations aggregate around an octamolybdate anion via hydrogen bonding interactions,
forming a “flowerpot” supramolecular network. Compound 2 is constructed from [α-Mo8O26]4− anions bridged through [Cu(dpoen)]2+ fragments into a 2D layered grid. Compounds 3 and 4 are Cu(I) and Cu(II) complexes bis-supported by [β-Mo8O26]4− anions, respectively. The electrochemical behaviors of compounds 1–4 modified solid bulk-modified carbon paste electrodes (1-MCPE-4-MCPE) have been studied. 相似文献
20.
Sumitava Khan Subhasis Roy Kishalay Bhar Partha Mitra Alexandra M. Z. Slawin Barindra Kumar Ghosh 《Transition Metal Chemistry》2011,36(1):99-106
Two hexacoordinated mononuclear Co(III) compounds of the type cis-[Co(L)(N3)2] X [1, X = ClO4; 2, X = PF6; L = N,N′-(bis(pyridine-2-yl)benzylidine)-1,4-butanediamine] have been synthesized and characterized by physicochemical and spectroscopic
methods. The crystal structures of complexes 1 and 2 both have distorted octahedral geometry with two terminal azides in mutual cis orientations. In the crystalline state, two
mononuclear units of 1 are associated by weak C–H…π interactions to produce a dimeric unit, which packs through C–H…O hydrogen bonds and π…π interactions
leading to a 2-D continuum. The mononuclear units in 2 are engaged in weak cooperative intermolecular C–H…π interactions and multiple C–H…F hydrogen bonds giving rise to a 3-D
network structure. These diamagnetic compounds are redox active and show luminescence in DMF solutions. 相似文献