999 resultados para C-2 oxygenates


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由2-(1,2-亚乙二硫)亚甲基-3-羰基-5-芳基-4-戊烯酸与三苯基氢氧化锡反应,合成了九个标题化合物3.用X射线衍射法测定了3b的晶体结构.该晶体属三斜晶系,空间群Pl,α=0.9074(2)nm,b=1.6809(3)nm,c=2.1834(4)nm,α=77.57(3)°,β=88.04(3)°,γ=89.47(3)°,V=3.2503nm~3,Z=2;R=0.0592.由锡氧原子间距离可推测,该晶体中羧酸根作为双齿配体与锡原子形成了分子内五配位结构.

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A novel compound was synthesized and characterized by means of elemental analysis, IR and UV spectra, TG, CV and single crystal X-ray diffraction. The compound crystallized in an orthorhombic space group C222 with a=1. 622 4(3) nm, b=3. 498 4(7) nm, c=1. 301 5(3) nm, V=7. 387 (3) nm(3), Z=6, R-1= 0. 037 3, wR(2)=0. 114 0. The Ala (Ala = alanine) molecules were protonated at the amino nitrogen N (1) and the C (2) of Ala group with the terminal oxygen atom O(15), O(14), O(26) and O(27) of the polyoxometalates participating in the hydrogen bond network. The anti-tumor activity of the title compound was estimated against Hela and Pc-3m cancer cells.

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Reaction of thiamine or thiamine monophosphate (TMP) with K2Pt(NO2)(4) afforded a metal complex, Pt(thiamine)(NO2)(3) (1), and two salt-type compounds, (H-thiamine)[Pt(NO2)(4)]. 2H(2)O (2) and (TMP)(2)[Pt(NO2)(4)]. 2H(2)O (3), which were structurally characterized by X-ray diffraction. In 1, the square-planar Pt2+ ion is coordinated to the pyrimidine N(1'), a usual metal-binding site, and three NO2- groups. The thiamine molecule exists as a monovalent cation in 1 and a divalent cation in 2 while the TMP molecule is a monovalent cation in 3. In each compound, thiamine or TMP adopts the usual F conformation and forms two types of host-guest-like interactions with anions, which are of the bridging forms, C(2)-H . . . anion . . . pyrimidine-ring and N(4'1)-H(...)anion(...)thiazolium-ring. In 3, there is an additional anion-bridging interaction between the pyrimidine and thiazolium rings of TMP, being of the form C(6')-H . . . anion . . . thiazolium-ring. The salts 2 and 3 show similar hydrogen-bonded cyclic dimers of thiamine or TMP between which the anions are held. Results are compared with those of the other thiamine-platinum complexes. (C) 2001 Elsevier Science B.V. All rights reserved.

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The title supramolecular compound, [HMDH2][(H2PMoMo11O40)-Mo-V] . 2AA . 3H(2)O . DMF (HMD = hexamethylene diamine; AA=acetaldehyde; DMF=N,N-dimethyl formamide), has been photochemically synthesized by using elemental analysis, IR, solid diffusion reflectance, electronic spectra, ESR spectra and X-ray single-crystal analysis. The crystallographic data: triclinic, P (1) over bar, a=14.092(2), b=14.347(3), c=14.358(3)Angstrom, alpha = 75.10(3), beta = 80.70(3), gamma = 80.73(3)degrees, V = 2746.6(10)Angstrom (3), Z = 2, M-r = 2081.68, D-c=2.517g/cm(3), F(000) =1970, mu (MoK alpha) =2.766mm(-1). The structure has been refined to R =0.0832 and wR=0.2638, by full-matrix least-squares method. The title compound is composed of hexamethylene diamine, two acetaldehyde molecules, three water molecules, one N,N-dimethylformamide and [(H2PMoMo11O40)-Mo-V](2-) heteropoly anion.

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Four new compounds AgLnW(2)O(8) (Ln = Eu, Gd, Tb and Dy) are prepared by solid-state reactions. They crystallize with a scheelite-related monoclinic symmetry. Infrared (IR) spectra show complicated absorption transitions in the region of 1000-400 cm(-1) that are similar to those of AgLnMo(2)O(8). Broad excitation and emission bands of the tungstate group are observed in AgGdW2O8 and AgTbW2O8 with a large Stokes shift, 12 573 and 12 387 cm(-1), respectively. Excitation and emission spectra of AgLnW(2)O(8) (Ln = Eu, Gd and Tb) show that energy transfer from the tungstate to EU3+, Gd3+ and Tb3+ occurs and that Eu3+ ions occupy a single crystallographic site with the C-2 Site symmetry. (C) 1997 Elsevier Science Ltd. All rights reserved.

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LaC3n+ (n = 0, 1, 2) clusters have been studied using B3LYP (Becke 3-parameter-Lee-Yang-Parr) density functional method. The basis set is Dunning/ Huzinaga valence double zeta for carbon and [2s2p2d] for lanthanum, denoted LANL1DZ. Four isomers are presented for each cluster; two of them are edge binding isomers with C-2 upsilon symmetry, the other two are Linear chains with C-infinity upsilon symmetry. Meanwhile, two spin states for each isomer, that is, singlet and triplet for LaC3+, doublet and quartet for LaC3 and LaC32+, respectively, are also considered. Geometries, vibrational frequencies, infrared intensities, and other quantities are reported and discussed. The results indicate that at some spin states; the C-2 upsilon symmetry isomers are the dominant structures, while for the other spin states, linear isomers are energetically favored. (C) 1998 John Wiley & Sons, Inc.

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The title compound, C20H22N2O2, is C-2 symmetric with the two N atoms bonded to salicylidene groups which are trans with respect to the cyclohexane ring.

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A new heteropolycomplex, K6H3[ZnW11O40Al] . 9.5H(2)O was prepared and characterized by means of elemental analysis, IR, UV spectroscopy, Al-27 NMR, electrochemistry and X-ray crystallography. The crystal of K6H3[ZnW11O40Al] . 9.5H(2)O is cubic, space group Fm-3m, with lattice constants a=b=c=2. 144 8(2) nm, V = 9.866(2) nm(3), Mo radiation, R = 0.057 8 for 497 independent data with [I>2 delta(I)]. The anion is of alpha-type Keggin structure with C-s symmetry.

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The crystal structure and mechanism of the title molecule are described. This crystal is orthorhombic, belonging to space group PC21/B with a=1,002 1(2) nm, b=1.483 0(3) nm, c=2.173 6(4) nm, V=3.230 39(2) nm(3), Z=2, D-c=1.80 g/cm(3), R=0.069 3. The structure was solved by direct method. The tin atom of the title compound exists in two distorted-trigonal-bipyramidal geometry, defined by two carbon, one bromide, one chloride and one oxygen atoms leading to a five-membered chelate ring. In the structure, the five-membered ring containing the intermolecular O-->Sn has a half chair conformation.

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Three new compounds, AgLnW(2)O(8) (Ln(3+)=Eu, Gd or Tb), have been prepared by a solid-state reaction and crystallize with a scheelite-related monoclinic symmetry. Their IR spectra show absorption transitions in the region 1000-400 cm(-1) similar to KLnW(2)O(8). Broad excitation and emission bands of the tungstate group with a large Stokes shift (12573 cm(-1)) are observed in AgGdW2O8. Excitation and emission spectra of AgLnW(2)O(8) (Ln=Eu or Tb) show that energy transfer from tungstate to Eu and Tb occurs and that Eu3+ ions occupy a unique crystallographic site with C-2 site symmetry.

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[(C6H5CH2C5H4)(2)GdCl . THF](2) (1) and (C6H5CH2C5H4)(2)ErCl . THF (2) were prepared by the reaction of LnCl(3) (Ln=Gd, Er) with benzylcyclopentadienyl sodium in THF and characterized by elemental analysis, IR, H-1 NMR, C-13 NMR, MS and thermal gravimetry. The crystal structures of both compounds were determined. Complex 1 is dimeric and its structure belongs to the monoclinic, P2(1)/c space group with a=1.1432(2), b=1.2978(2), c=1.7604(3) nm, beta=108.75(2), V=2.4732(9) nm(3), Z=2(four monomers), D-c=1.54 g . cm(-3). R=0.0342 and R(w)=0.0362. Complex 2 is monomer and its structure belongs to the orthorhombic, P2(1)2(1)2(1) space group with a=0.8645(2), b=1.1394(3), c=2.5289(4) nm, V=2.4919(9) nm(3), Z=4, D-c=1.56 g . cm(-3). R=0.0514, R(w)=0.0529. The determination of the crystal structure shows that in complex 1 the benzyl groups on the cyclopentadienyls coordinated to Gd3+ are located in the opposite direction (139 degrees); in complex 2 the benzyl groups on the cyclopentadienyls coordinated to Er3+ are located in the same direction (6.5 degrees).

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The ansa-zirconocene derivative tetramethyldisiloxandiyl bis(1-indenyl) zirconium dichloride (1) has been prepared by the reaction of the dilithium salt of 1,3-bis(l-indenyl) tetramethyldisiloxane with ZrCl4 . 2THF, After catalytic hydrogenation, the corresponding tetrahydroindenyl complex (2) has been formed. Both 1 and 2 have been shown by H-1 NMR spectra to be the mixture of the cis(meso) and trans(rac) isomers, The pure trans isomers 1(l), 2(l) and cis isomer 2(c) were obtained by recrystallization, The crystal structures of 1(l) and 2(c) were determined by X-ray diffraction. Both crystals of 1(l) and 2(c) are monoclinics, belonging to space groups P2(1)/n(1(l)) and P2(1)/c(2(c)). In the unit cell of 2(c), one of the six-membered rings of the tetrahydroindenyl Ligands has two different conformations which have the same probabilities.

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A new double phosphate, KCaY(PO4)(2), isostructural with hexagonal LaPO4, is reported. It crystallizes in the hexagonal system with a = 0.6903 nm and c = 0.6331 nm. Its vibrational spectra, IR and Raman spectra showed that the site symmetry of the PO4 anion slightly deviated from D-2 toward C-2.

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在前报中,从对η~6-苯钐配合物Sm(η~6-C_6H_5)(η~2-AlCl_4)_3的晶体结构测定,得到配合物中Sm-C键平均键长为2.92 ,这一结果,与Cotton报道的Sm(η~6-C_6Me_6)(η~6-AICI_4)_3中的Sm-C键平均键长(2.89 )相比,明显地增大了。可见,配体芳烃与相应的稀土有机配合物的结构有着密切的关系。为了进一步了解苯环上甲基取代数目对这类配合物结构的影响规律,我们以甲苯为配体,研究了η~6-甲苯钐有机配合物的合成及晶体结构。

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the novel One-dimensional chain structure of the title cluster compound was synthesized and characterized by elemental analysis, IR spectra, TGA and X-ray single-crystal diffraction. The title cluster compound crystallized in a monochnic system with space group C2/c, a = 1.2656 nm, b = 2.20656 (4) nm, c =2.26763 (4) nm, beta = 92.078 degrees, V = 6.32852 (16) nm(3), Z = 4, D-c = 3.801 g/cm(3), A = 2.271 mm(-1), F(000) = 6512, R-1= 0.0549, wR(2) = 0.1087. The structure building block of the structure is the polyanion [SiW12O40](6-) with alpha-Keggin structure. The clusters were linked together with one-dimensional infinite chain through [ Ni ( enMe) (2)] (2+) cations. The [ Ni ( enMe) (2) ( H2O) (2)] (2+) cations and water molecules were filled in the structure. The cluster compound was expanded to three-dimensional framework by hydrogen bond interactions among molecules.