Electrochemical control of bridging ligand conformation in a binuclear complex—A possible basis for a molecular switch
作者:Laurent F. Joulié、Erik Schatz、Michael D. Ward、Frank Weber、Lesley J. Yellowlees
DOI:10.1039/dt9940000799
日期:——
state. The change from planar to twisted therefore occurs at the extremes of the redox series, on formation of the cat–cat and q–q oxidation states. This control of bridging ligand conformation with oxidation state may form the basis for a molecularswitch.
所述binucleating桥接的配体反应的3,3',4,4'- tetrahydroxybiphenyl(H 4大号1)或3,3“,4,4”-tetrahydroxy- p -三联苯(H 4大号2)与2个当量的[ Ru(bipy)2 Cl 2 ]·2H 2 O(bipy = 2,2'-联吡啶)导致双核络合物的形成[Ru(bipy)2 }(µ-L)Ru(bipy)2 }] 2 + 1(L = L 1)和2(L = L 2),其中配体L 4–被氧化为L 2–的半醌(sq)。在每个复合物中,邻苯二酚碎片(猫)可能被可逆氧化为半醌和醌(q)氧化还原态,从而得到五元氧化还原系列cat-cat,cat-sq,sq-sq,sq-q和q–q为桥连配体。在平方状态下,由于芳环之间存在双键,桥连的配体必定是平面的。在cat-cat和q-q状态下,芳环之间没有正式的双键特征,它们可以自由选择扭曲的构象。光
Synthesis and Characterization of a New Series of Binuclear Pd(II) Biscatecholato Complexes: Non-Innocent Ligand-Based Approach to a Wide Range of Variation in Near-Infrared Absorptions of Mixed-Valence Complexes
In this study, we report synthesis of a newseries of mixed-valence (MV) complexes having intervalence charge transfer (IVCT) energies variable from the first to the third telecommunication window....
Synthesis of tetrahydroxybiphenyls and tetrahydroxyterphenyls and their evaluation as amyloid-β aggregation inhibitors
作者:Craig B. Stevens、James M. Hanna、Robin K. Lammi
DOI:10.1016/j.bmcl.2013.01.076
日期:2013.3
3,3',4,4'-Tetrahydroxybiphenyl and three isomeric 3,3 '',4,4 ''-tetrahydroxyterphenyls with varying geometries around the central phenyl ring have been synthesized and evaluated for their in vitro activity against aggregation of Alzheimer's amyloid-beta peptide (A beta). Results from Congo red spectral-shift assays reveal that all four compounds successfully inhibit association of A beta monomers. For the tetrahydroxyterphenyls, efficacy varies with linker geometry: the ortho-arrangement affords the most successful inhibition and the para-geometry the least, perhaps due to differing abilities of these compounds to bind A beta. Of the four small molecules studied, 3,3',4,4'-tetrahydroxybiphenyl is the most effective inhibitor, reducing A beta aggregation by 50% when present in stoichiometric concentrations. (C) 2013 Elsevier Ltd. All rights reserved.