972 resultados para 1-METHYL-4-PHENYL-1,2,3,6-TETRAHYDROPYRIDINE MODEL


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Bistriazoles, 1,3-bis(1,2,4-triazol-4-yl)propane (tr2pr) and 1,3-bis(1,2,4-triazol-4-yl)adamantane (tr2ad), were examined in combination with the rigid tetratopic 1,3,5,7-adamantanetetracarboxylic acid (H4-adtc) platform for the construction of neutral heteroleptic copper(II) metal−organic frameworks. Two coordination polymers, [{Cu4(OH)2(H2O)2}{Cu4(OH)2}(tr2pr)2(H-adtc)4]·2H2O (1) and [Cu4(OH)2(tr2ad)2(H-adtc)2(H2O)2]·3H2O (2), were synthesized and structurally characterized. In complexes 1 and 2, the N1,N2-1,2,4-triazolyl (tr) and μ3-OH− groups serve as complementary bridges between adjacent metal centers supporting the tetranuclear dihydroxo clusters. The structure of 1 represents a unique association of two different kinds of centrosymmetrical {Cu4(OH)2} units in a tight 3D framework, while in compound 2, another configuration type of acentric tetranuclear metal clusters is organized in a layered 3,6-hexagonal motif. In both cases, the {Cu4(OH)2} secondary building block and trideprotonated carboxylate H-adtc3− can be viewed as covalently bound six- and three-connected nodes that define the net topology. The tr ligands, showing μ3- or μ4-binding patterns, introduce additional integrating links between the neighboring {Cu4(OH)2} fragments. A variable-temperature magnetic susceptibility study of 2 demonstrates strong antiferromagnetic intracluster coupling (J1 = −109 cm−1 and J2 = −21 cm−1), which combines for the bulk phase with a weak antiferromagnetic intercluster interaction (zj = −2.5 cm−1).

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The synthesis of the three N,N′-di(4-coumaroyl)tetramines, i.e., of (E,E)-N-{3-[(2-aminoethyl)amino]propyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] (1a), (E,E)-N-{4-[(2-aminoethyl)amino]butyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] (1b), and (E,E)-N-{6-[(2-aminoethyl)amino]hexyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(ethane-1,2-diyl)bis[prop-2-enamide] (1c), is described. It proceeds through stepwise construction of the symmetric polyamine backbone including protection and deprotection steps of the amino functions. Their behavior on TLC in comparison with that of 1,4-di(4-coumaroyl)spermine (=(E,E)-N-{4-[(3-aminopropyl)amino]butyl}-3,3′-bis(4-hydroxyphenyl)-N,N′-(propane-1,3-diyl)bis[prop-2-enamide]; 2) is discussed.

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A bitopic ligand, 4-(3,5-dimethylpyrazol-4-yl)-1,2,4-triazole (Hpz-tr) (1), containing two different heterocyclic moieties was employed for the design of copper(II)–molybdate solids under hydrothermal conditions. In the multicomponent CuII/Hpz-tr/MoVI system, a diverse set of coordination hybrids, [Cu(Hpz-tr)2SO4]·3H2O (2), [Cu(Hpz-tr)Mo3O10] (3), [Cu4(OH)4(Hpz-tr)4Mo8O26]·6H2O (4), [Cu(Hpz-tr)2Mo4O13] (5), and [Mo2O6(Hpz-tr)]·H2O (6), was prepared and characterized. A systematic investigation of these systems in the form of a ternary crystallization diagram approach was utilized to show the influence of the molar ratios of starting reagents, the metal (CuII and MoVI) sources, the temperature, etc., on the reaction products outcome. Complexes 2–4 dominate throughout a wide crystallization range of the composition triangle, while the other two compounds 5 and 6 crystallize as minor phases in a narrow concentration range. In the crystal structures of 2–6, the organic ligand behaves as a short [N–N]-triazole linker between metal centers Cu···Cu in 2–4, Cu···Mo in 5, and Mo···Mo in 6, while the pyrazolyl function remains uncoordinated. This is the reason for the exceptional formation of low-dimensional coordination motifs: 1D for 2, 4, and 6 and 2D for 3 and 5. In all cases, the pyrazolyl group is involved in H bonding (H-donor/H-acceptor) and is responsible for π–π stacking, thus connecting the chain and layer structures in more complicated H-bonding architectures. These compounds possess moderate thermal stability up to 250–300 °C. The magnetic measurements were performed for 2–4, revealing in all three cases antiferromagnetic exchange interactions between neighboring CuII centers and long-range order with a net moment below Tc of 13 K for compound 4.

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"The Aftermath of National Socialism. On the Cultural Aspects of the Collapse of National Socialism". Vorlesungsreihe des Instituts für Sozialforschung, März 1945; 1. Vorlesungsankündigung und Typoskripte der Beiträge von: Theodor W. Adorno, "The Fate of the Arts" (= "What National Socialism Has Done to the Arts"); Frederick Pollock, "Prejudice and the Social Classes"; Leo Löwenthal, "The Aftermath of Totalitarian Terror". Bibliographie, Typoskripte, geheftet, mit eigenhändiger Korrektur von Frederick Pollock, 93 Blatt; 2. Vorlesungsankündigung, als Typoskript vervielfältigt, 1 Blatt; 3. Max Horkheimer: "Totalitarism and the Crisis of European Culture". Eigene Notizen zur Vorlesung, 3 Blatt; 4. Theodor W. Adorno: Notizen zur Vorlesungsreihe. Typoskript, 2 Blatt; Max Horkheimer: "National Socialism and Philosophy". Seminar Frühjahr 1945; 1. Protokolle zu den Sitzungen vom 5.2, 24.4., 1.5. und 8.5.1945. Typoskript mit eigenhändiger Korrektur, 16 Blatt; 2. Dasselbe. Gebunden, 16 Blatt; 3. Eigenhändige Notizen, 8 Blatt; Max Horkheimer: "The Idea of Philosophy". Vorlesung Winter 1945/46; 1. Eigenhändige Notizen, 3 Blatt; 2. Eigenhändige Notizen, 4 Blatt; 3. Eigenhändige Notizen, 2 Blatt; 4. Abschriften aus Werken unter anderem von Friedrich von Bezold, Karl Lamprecht, Richard Pietchman, Leopold von Ranke, Edwin R.A. Seligman. Typoskripte, 8 Blatt; 5. Paul Tillich: "Conscience in Western Thought and the Idea a Transmoral Conscience". Sonderdruck aus: Crozer Quarterly, Vol. XXII, Nr. 4, Oktober 1945, 6 Blatt; Max Horkheimer: Programm einer Intereuropäischen Akademie, 1944/45 (?); 1. Typoskriptfassungen, englisch. a) Typoskript, 18 Blatt b) Typoskript mit handschriftlicher Korrektur von Theodor W. Adorno (GS 12, S.195-213), 18 Blatt c) Typoskript (Kopie) mit handschriftliche Korrektur, 18 Blatt (Kopie 1989 aus der Hoover Institution, Standford, California) d) Typoskript mit eigenhändiger Korrektur, 17 Blatt e) Korrektur-Teilstücke, Typoskripte mit eigenhändiger Korrektur, 2 Blatt; 2. Zeitungsausschnitt 1944, 1 Blatt;

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Hyperacute rejection of a porcine organ by higher primates is initiated by the binding of xenoreactive natural antibodies of the recipient to blood vessels in the graft leading to complement activation. The majority of these antibodies recognize the carbohydrate structure Gal(alphal,3)Gal (gal epitope) present on cells of pigs. It is possible that the removal or lowering of the number of gal epitopes on the graft endothelium could prevent hyperacute rejection. The Gal(alpha1,3) Gal structure is formed by the enzyme Galbeta1,4GlcNAc3-alpha-D-galactosyltransferase [alpha(1,3)GT; EC 2.4.1.51], which transfers a galactose molecule to terminal N-acetyllactosamine (N-lac) present on various glycoproteins and glycolipids. The N-lac structure might be utilized as an acceptor by other glycosyltransferases such as Galbeta1,4GlcNAc 6-alpha-D-sialyltransferase [alpha(2,6)ST], Galbeta1,4GlcNAc 3-alpha-D-Sialyltransferase [alpha(2,3)ST], or Galbeta 2-alpha-L-fucosyltransferase [alpha(1,2)FT; EC 2.4.1.691, etc. In this report we describe the competition between alpha(1,2)FT and alpha(1,3)GT in cells in culture and the generation of transgenic mice and transgenic pigs that express alpha(1,2)Fr leading to synthesis of Fucalpha,2Galbeta- (H antigen) and a concomitant decrease in the level of Gal(alpha1,3)Gal. As predicted, this resulted in reduced binding of xenoreactive natural antibodies to endothelial cells of transgenic mice and protection from complement mediated lysis.