Search results for "BIM."
showing 10 items of 365 documents
Evidence of intramolecular electron transfer between two metallic atoms in a bimetallic complex by electrochemical methods
2005
The electrochemical properties of the monomeric complex [(η5-C5H5)(μ-η5:η1-C5H4(CH2)2P(C6H5)2TiCl2] 1 and the heterobimetallic complex [(η5-C5H5)(μ-η5:η1-C5H4(CH2)2P(C6H5)2TiCl2][RuCl2(C6H4(CH3)(C3H7))] 2 have been studied by cyclic voltammetry, controlled potential electrolysis and rotating disk electrode voltammetry. An unexpected electron transfer between the two heterobimetallic atoms has been observed. This transfer takes place via an intramolecular interaction, hence via a chloride bridge. Electrochemical simulation has been carried out to verify experimental results and to obtain the kinetic constant of the proposed square scheme.
Confocal microscopy of single molecules of the green fluorescent protein
1998
Single molecule detection has been extended into life sciences by use of strongly fluorescent labels. The green fluorescent protein (GFP) as a self-fluorescent biomolecule has attracted considerable attention. Here, single molecules of the GFP-mutant Glu222Gln are immobilized in a polyvinylalcohol matrix and detected by confocal fluorescence microscopy. Although this mutant stabilizes one of both conformers of the wild-type GFP, the investigation of its fluorescence dynamics reveals strong signal fluctuations. This fluorescence behaviour is—at least partly—caused by reversible photochemical changes of the protein framework, that can relax into the fluorescent state on different timescales. …
Layered Molecule-Based Magnets Formed by Decamethylmetallocenium Cations and Two-Dimensional Bimetallic Complexes [MIIRuIII(ox)3]−(MII=;Mn, Fe, Co, C…
2001
Abstract A new series of hybrid organometallic-inorganic layered magnets with formula [Z III Cp * 2 ] [M II Ru III (ox) 3 ] ( Z III =Co and Fe; M II =Mn, Fe, Co, Cu, and Zn; ox=oxalate: Cp * =pentamethylcyclopentadienyl) has been prepared. All of these compounds are isostructural to the previously reported [ Z III Cp * 2 ] [ M II M III (ox) 3 ] ( M III =Cr, Fe) series and crystallize in the monoclinic space group C 2/ m , as found by powder X-ray diffraction analysis. They are novel examples of magnetic materials formed by bimetallic oxalate-based extended layers separated by layers of organometallic cations. The magnetic properties of all these compounds have been investigated (ac and dc m…
Molecule-Based Magnets Formed by Bimetallic Three-Dimensional Oxalate Networks and Chiral Tris(bipyridyl) Complex Cations. The Series [ZII(bpy)3][ClO…
2000
The synthesis, structure, and physical properties of the series of molecular magnets formulated as [ZII(bpy)3][ClO4][MIICrIII(ox)3] (ZII = Ru, Fe, Co, and Ni; MII = Mn, Fe, Co, Ni, Cu, and Zn; ox = oxalate dianion) are presented. All the compounds are isostructural to the [Ru(bpy)3][ClO4][MnCr(ox)3] member whose structure (cubic space group P4(1)32 with a = 15.506(2) A, Z = 4) consists of a three-dimensional bimetallic network formed by alternating MII and CrIII ions connected by oxalate anions. The identical chirality (lambda in the solved crystal) of all the metallic centers determines the 3D chiral structure adopted by these compounds. The anionic 3D sublattice leaves some holes where th…
Trans-dicyanobis(acetylacetonato)ruthenate(III) as a precursor to build novel cyanide-bridged RuIII–MII bimetallic compounds [M=Co and Ni]
2006
Abstract The use of the mononuclear complex trans-[Ru(acac)2(CN)2]− as a ligand towards the preformed species [Ni2L(H2O)2Cl2], [Co(dmphen)](NO3)2, [Ni(dmphen)](NO3)2 and [Co(H2O)6](NO3)2 afforded the novel cyanide-bridged bimetallic compounds of formula [{Ru(acac)2(CN)2}{Ni2(L)(H2O)2}]{Ru(acac)2(CN)2}·2H2O (1), [{Ru(acac)2(CN)2}{Co(dmphen)(NO3)}]·H2O (2) and [{Ru(acac)2(CN)2}{Ni(dmphen)(NO3)}]·H2O (3) and [{Ru(acac)2(CN)2}2Co] (4) [Hacac = acetylacetone, dmphen = 2,9-dimethylphenanthroline and H2L = 11,23-dimethyl-3,7,15,19-tetrazatricyclo[19.3.1.19,13]hexacosa-2,7,9,11,13(26),14,19,21(25),22,24-decaene-25,26-diol]. Their syntheses, X-ray crystal structures and magnetic properties are repor…
Syntheses and characterization of novel ruthenium complexes based on 1,3-dicyanobenzene
2007
Submitted by António Freitas (amsf@uma.pt) on 2019-06-14T13:25:52Z No. of bitstreams: 1 Syntheses and Characterization of Novel Ruthenium Complexes Based on 13-DicyanobenzeneJoãoRodrigues.pdf: 354444 bytes, checksum: edc8aaaa84900d75321648e76e0c8e27 (MD5) Made available in DSpace on 2019-06-14T13:25:52Z (GMT). No. of bitstreams: 1 Syntheses and Characterization of Novel Ruthenium Complexes Based on 13-DicyanobenzeneJoãoRodrigues.pdf: 354444 bytes, checksum: edc8aaaa84900d75321648e76e0c8e27 (MD5) Previous issue date: 2007 info:eu-repo/semantics/publishedVersion
Incommensurate nature of the multilayered molecular ferromagnetic metals based on bis(ethylenedithio)tetrathiafulvalene and bimetallic oxalate comple…
2004
The salt [ET]x[MnRh(ox)(3)].CH(2)Cl(2) (x = 2.526(1)) has been obtained and characterized. This paramagnetic metal is essentially isostructural to the ferromagnetic metal [ET]y[MnCr(ox)(3)].CH(2)Cl(2) (y approximately equal to 3) and provides a definite answer on the origin of the structural disorder present on such systems. As in the ferromagnetic analogue, this material shows high electrical conductivity at room temperature (13 S.cm(-1)) and metallic behavior.
Thermal stability and reaction of chalcogen-containing metallocenic compounds with elemental chalcogens
1989
Abstract Dissymmetrical four-membered bimetallocenacycles (t-BuC 5 H 4 ) 2 M(μ-S) 2 M′-(RC 5 H 4 ) 2 (M, M′ = Zr, Hf; R = H, t-Bu) have been prepared and found to give redistribution products in solution at 190°C; identification of these products shows that the reaction involves exclusive cleavage of a metal-sulfur bond. Elemental sulfur and selenium react with chalcogen-containing complexes. The reaction is shown to involve the introduction of chalcogenic species in place of the σ-ligands of the complex to give either four-membered bimetallic complexes or catenated pentachalcogen metallocenic compounds. Some examples of insertion of sulfur and tellurium into the zirconium-methyl bond are a…
Synthesis of μ-C2S44− Cobalt Complexes by Activation of the 1,3,4,6-tetrathiapentalene-2,5-dione, and Electrochemical Study of [(Cp*Co)2(μ-C2S4)]
2002
The bimetallic complex [Cp(*)Co)2(μ-C2S4)] in which the two metal centres are linked by an ethylenetetrathiolate C2S44− unit, was synthesized in high yield by oxidative addition of 1,3,4,6 tetrathiapentalene-2,5-dione to [Cp(*)Co(CO)2]. The X-ray crystal structure of the intermediate product Cp*Co(dmid) (dmid2− = 4,5-disulfanyl-1,3-dithiol-2-onate) is presented. The electrochemical behaviour of the [(Cp*Co)2(μ-C2S4)] complex was studied in detail in the oxidative range. This study has shown that the nature of the product obtained after oxidation depends on the presence of complexing agent in the solution. The mechanism has been elucidated in a CH2Cl2 solution in the presence of P(OMe)3. In …
Dihydrogen complexes of metalloporphyrins: characterization and catalytic hydrogen oxidation activity
1992
A series of monometallic dihydrogen complexes of the type M(OEP)(L)(H{sub 2}) (M = Ru, Os; L = THF, *Im) was synthesized and characterized by {sup 1}H NMR. The H-H bond length was found to increase when Os was replaced by Ru or when *Im was replaced by THF. The bond distances (as determined by T{sub 1}) range from 0.92 to 1.18 {angstrom}. The first example of a bimetallic bridging dihydrogen complex, Ru{sub 2}(DPB)(*IM){sub 2}(H{sub 2}), was also prepared. The H{sub 2} ligand is simultaneously bound to both Ru-metal centers. High-field {sup 1}H NMR experiments (620 MHz) revealed a -7.37 Hz dipolar splitting of the H{sub 2} ligand for this complex. Analysis of this splitting suggests that th…