956 resultados para Oligomers, Supramolecular Chemistry, Solid Supported Synthesis, Blockcopolymers
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232 p.
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Póster presentado en: 11th International Symposium on Applied Bioinorganic Chemistry. 2-5 Diciembre 2011. Barcelona, España (ISABC 2011)
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Three new types of aryl diketo acid (ADK) isosteres were designed by conversion of the biologically labile 1,3-diketo unit into heteroaromatic motif such as isoxazole, isothiazole, or 1H-pyrazole to improve the physicochemical property of ADK-based HIV-1
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We describe a facile one-pot process to synthesize Ag nanoplates by reducing silver nitrate with 3,3',5,5'-tetramethylbenzidine (TMB) at room temperature. The silver nanoplates were highly oriented single crystals with (111) planes as the basal planes. TMB can be readily oxidized to charge-transfer (CT) complex between TMB, as a donor, and (TMB)(2+), as an acceptor. The pi-pi interaction of the neutral amine (TMB) and diiminium structure (dication, TMB2+) result in the formation of one-dimensional CT complex nanofiber.
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A neutral open-frame work zincophosphate has been hydrothermally synthesized: structure refinement shows that it is composed of Zn4O12 tetramers and infinite Zn-O-Zn chains that are linked by PO4 groups forming one-dimensional 16-membered ring channels along b direction.
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The preparation and characteristics of bilayer lipid membranes including conventional bilayer membrane, solid supported self-assembling bilayer lipid membrane, solid supported hybrid bilayer membrane are described in this paper, The applications of bilayer lipid membranes in electrochemical biosensors are reviewed and the future development of electrochemical biosensor based on bilayer lipid membranes is discussed.
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The half-sandwich tert-butyl cyclopentadienyl lanthanoid complexes {[Cp ' Ln(THF)](2)(mu (2)-Cl)(2)(mu (3)-Cl)(3)Na(THF)}(n) [Cp ' = eta (5)-' BuC5H4; Ln = Nd (1a), Sm (1b), Gd (1c), Yb (1d)] are prepared by the reaction of anhydrous lanthanoid trichloride, LnCl(3), with NaCp ' in THF solution. Complex 1b reacts with Na2Se5 to give hexanuclear samarium polyselenide complexes [Na(THF)(6)](2)[Cp-6' SM6(mu (6)-Se)(mu -Se-2)(6)] (2). An analogous cyclopentadienyl neodymium polyselenide complex [Li(THF)(4)](2)[Cp6Nd6(mu (6)-Se)(mu -Se-2)(6)] (3) is synthesized by the reaction of [CpNdCl2. 2LiCl . 5THF] with Na2Se5 in THF solution. The molecular structures of 1a and 2 were determined by X-ray crystal structure analysis. Complex 2 contains an interstitial selenium atom which is coordinated with six samarium atoms. (C) 2001 Elsevier Science BN. All rights reserved.
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Co(En)(3)MoO4 was synthesized by using the method of hydrothermal synthesis and characterized by elemental analysis, IR, ESR and single-crystal X-ray methods. It crystallizes in hexagonal space group P (3) over bar C1 with a=1.596 4(2) nm, b=1.596 4(2) nm, c = 0.993 5(2) nm, alpha=beta=90 degrees gamma=120 degrees, M-c=399.18, V=2.192 6(6) nm(3), D-c=1.814 g/nm(3), Z=6, F(000)=1 2181 R-1=0.070 3, R-w=0.220 7. According to separation of anion which acted on electrostatic potential, the anion and cation ions formed a type of organic and inorganic material.
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Me4C2(C5H4MgCl)2(THF) (THF = tetrahydrofuran) reacts with anhydrous SmCl3 in THF to give [Me4C2CP2SMCl.THF]2. The molecule is a dimer. Sm1 and Sm2 are bridged unsymmetrically by two chlorine atoms [Sm(1)-CI(1) 2.787(2), Sm(1)-Cl(2) 2.848(2), Sm(2)-Cl(1) 2
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Two lanthanum(III) [2,2,2]cryptates, [LaCl[2,2,2](H2O)]Cl-2.H2O (1) and [La(CF3SO3)[2,2,2](DMF)] (CF3SO3)(2) (2) have been prepared by the reaction of LaCl3 and La(CF3SO3)(3) with [2,2,2]cryptand, respectively and their crystal structures have been determ
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Cp3Yb (Cp = C5H5) reacts with a-naphthol (HNP) in THF to form Cp2Yb(NP)(THF) (1), which crystallizes in the space group P2(1)/n with unit cell dimensions a = 8.084(2), b = 15.996(6), c = 15.973(7) angstrom, beta = 98.95(3), V = 2040.3 angstrom and D(calc.) = 1.69 g cm-3 for Z = 4. Least-squares refinement based on 2242 observed reflections converged to a final R value of 0.081. The average Yb-C(Cp) distance is 2.60(2) angstrom and Yb-O(THF) and Yb-O(NP) distances are 2.30(1) and 2.06(1) angstrom, respectively. The title compound loses the coordinated THF molecule readily by heating under vacuum to give dimeric [Cp2Yb(NP)]2 (2), which undergoes disproportionation to give Cp3Yb and Yb(NP)3 on heating above 230-degrees-C.
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The research described in this thesis focuses on the design and synthesis of stable α-diazosulfoxides and investigation of their reactivity under a variety of conditions (transition-metal catalysis, thermal, photochemical and microwave) with a particular emphasis on the synthesis of novel heterocyclic compounds with potential biological activity. The exclusive reaction pathway for these α-diazosulfoxides was found to be hetero-Wolff rearrangement to give α-oxosulfine intermediates. In the first chapter, a literature review of sulfines is presented, including a discussion of naturally occurring sulfines, and an overview of the synthesis and reactivity of sulfines. The potential of sulfines in organic synthesis and recent developments in particular are highlighted. The second chapter discusses the synthesis and reactivity of α-diazosulfoxides, building on earlier results in this research group. The synthesis of lactone-based α-diazosulfoxides and, for the first time, ketone-based benzofused and monocyclic α-diazosulfoxides is described. The reactivity of these α-diazosulfoxides is then explored under a variety of conditions, such as transition-metal catalysis, photochemical and microwave, generating labile α-oxosulfine intermediates, which are trapped using amines and dienes, in addition to the spontaneous reaction pathways which occur with α-oxosulfines in the absence of a trap. A new reaction pathway was explored with the lactone based α-oxosulfines, involving reaction with amines to generate novel 3-aminofuran-2(5H)-ones via carbophilic attack, in very good yields. The reactivity of ketone-based α-diazosulfoxides was explored for the first time, and once again, pseudo-Wolff rearrangement to the α-oxosulfines was the exclusive reaction pathway observed. The intermediacy of the α-oxosulfines was confirmed by trapping as cycloadducts, with the stereochemical features dependant on the reaction conditions. In the absence of a diene trap, a number of reaction fates from the α-oxosulfines were observed, including complete sulfinyl extrusion to give indanones, sulfur extrusion to give indanediones, and, to a lesser extent, dimerisation. The indanediones were characterised by trapping as quinoxalines, to enable full characterisation. One of the overriding outcomes of this thesis was the provision of new insights into the behaviour of α-oxosulfines with different transition metal catalysts, and under thermal, microwave and photolysis conditions. A series of 3-aminofuran-2(5H)-ones and benzofused dihydro-2H-thiopyran S-oxides were submitted for anticancer screening at the U.S. National Cancer Institute. A number of these derivatives were identified as hit compounds, with excellent cell growth inhibition. One 3-aminofuran-2(5H)-one derivative has been chosen for further screening. The third chapter details the full experimental procedures, including spectroscopic and analytical data for the compounds prepared during this research. The data for the crystal structures are contained in the attached CD.
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This thesis focuses on the synthesis and analysis of novel chloride based platinum complexes derived from iminophosphine and phosphinoamide ligands, along with studies on their reactivity towards substitution and oxidation reactions. Also explored here are the potential applications of these complexes for biological and luminescent purposes. Chapter one provides an extensive overview of platinum coordination chemistry with examples of various mixed donor ligands along with the history of platinum anticancer therapy. It also looks at metals in medicine, both for biological functions as well as for therapeutic purposes and gives a background to some other applications for platinum complexes. Chapter two outlines the design and synthetic strategies employed for the development of novel platinum (II) chloride complexes from iminophosphine and phosphinoamide ligands. Also reported is the cyclometallation of these complexes to form stable tridentate mixed donor platinum (II) compounds. In Chapter three the development of a direct method for displacing a chloride from a platinum metal centre with a desired phosphine is reported. Numerous methods for successful oxidation of the platinum (II) complexes will also be explored, leading to novel platinum (IV) complexes being reported here also. The importance of stabilisation of the displaced anion, chloride, by the solvent system will also be discussed in this chapter. Chapter four investigates the reactivity of the platinum (II) complexes towards two different biomolecules to form novel platinum bio-adducts. The potential application of the platinum (II) cyclometallates as chemotherapeutics will also be explored here using in-vitro cancer cell testing. Finally, luminescence studies are also reported here for the ligands and platinum complexes reported in chapter two and three to investigate potential applications in this field also. Chapter five provides a final conclusion and an overall summary of the entire project as well as identifying key areas for future work.
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A total synthesis of phomactin G (3), which is a central intermediate in the biosynthesis of phomactin A (5) in Phoma sp. is described. The synthesis is based on a Cr(II)/Ni(II) macrocyclisation from the aldehyde vinyl iodide 9, leading to 16, followed by sequential conversion of 16 into the -epoxide 21 and the ketone 25 which, on deprotection, led to (±)-phomactin G. Phomactin G (3) shares an interesting structural homology with phomactin D (2), the most potent PAF-antagonist metabolite in Phoma sp. It is most likely converted into phomactin A (5), by initial allylic oxidation to the transient -alcohol phomactin structure 4, known as Sch 49028, followed by spontaneous pyran ring formation.