A redox active switch for lanthanide luminescence in phenolate complexes

2017 ◽  
Vol 53 (3) ◽  
pp. 605-608 ◽  
Author(s):  
J. K. Molloy ◽  
O. Jarjayes ◽  
C. Philouze ◽  
L. Fedele ◽  
D. Imbert ◽  
...  
Keyword(s):  
Metal Ion ◽  
Phenoxyl Radicals ◽  
Lanthanide Luminescence ◽  
Redox Active ◽  
Active Switch

The reversible oxidation of coordinated phenolates into phenoxyl radicals results in a dramatic quenching (>95%) of the luminescence of the f metal ion.

Electrochemical characterization of Cu(II) complexes of brain-related tau peptides

2021 ◽  
Vol 99 (7) ◽  
pp. 628-636
Author(s):  
Camilla Golec ◽  
Jose O. Esteves-Villanueva ◽  
Sanela Martic
Keyword(s):  
Metal Ions ◽  
Tau Protein ◽  
Metal Ion ◽  
Differential Pulse ◽  
Redox Couple ◽  
Peptide Sequence ◽  
Binding Studies ◽  
Biologically Relevant ◽  
Redox Active ◽  
Competition Binding

Metal ion dyshomeostasis plays an important role in diseases, including neurodegeneration. Tau protein is a known neurodegeneration biomarker, but its interactions with biologically relevant metal ions, such as Cu(II), are not fully understood. Herein, the Cu(II) complexes of four tau R peptides, based on the tau repeat domains, R1, R2, R3, and R4, were characterized by electrochemical methods, including cyclic voltammetry, square-wave voltammetry, and differential pulse voltammetry in solution under aerobic conditions. The current and potential associated with Cu(II)/(I) redox couple was modulated as a function of R peptide sequence and concentration. All R peptides coordinated Cu(II) resulting in a dramatic decrease in the current associated with free Cu(II), and the appearance of a new redox couple due to metallo–peptide complex. The metallo–peptide complexes were characterized by the irreversible redox couple at more positive potentials and slower electron-transfer rates compared with the free Cu(II). The competition binding studies between R peptides with Cu(II) indicated that the strongest binding affinity was observed for the R3 peptide, which contained 2 His and 1 Cys residues. The formation of complexes was also evaluated as a function of peptide concentration and in the presence of competing Zn(II) ions. Data indicate that all metallo–peptides remain redox active pointing to the potential importance of the interactions between tau protein with metal ions in a biological setting.

Alkali-Metal-Ion-Directed Self-Assembly of Redox-Active Manganese(III) Supramolecular Boxes

2015 ◽  
Vol 54 (6) ◽  
pp. 2512-2521 ◽  
Author(s):  
Gustavo González-Riopedre ◽  
Manuel R. Bermejo ◽  
M. Isabel Fernández-García ◽  
Ana M. González-Noya ◽  
Rosa Pedrido ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Self Assembly ◽  
Metal Ion ◽  
Alkali Metal Ion ◽  
Redox Active

Cooperation of metals with electroactive ligands of biochemical relevance: Beyond metalloporphyrins

2004 ◽  
Vol 76 (2) ◽  
pp. 351-364 ◽  
Author(s):  
Wolfgang Kaim ◽  
B. Schwederski
Keyword(s):  
Electron Transfer ◽  
Transition Metals ◽  
Amine Oxidases ◽  
Phenoxyl Radicals ◽  
Functional Description ◽  
Model Studies ◽  
Substrate Activation ◽  
Redox Active ◽  
Factor F430

In addition to the widely studied biometal complexes of tetrapyrrole ligands such as hemes (Fe), cobalamins (Co), and factor F430 (Ni), there are other, more recently established systems in which transition metals and redox-active cofactors such as pterins, flavins, quinones, or phenoxyl radicals cooperate in electron transfer and substrate activation. The cases of the molybdenum or tungsten containing oxotransferases involving pyranopterin as essential ligand and the copper-dependent quinoproteins such as amine oxidases will be discussed. The structural and functional description of these systems will be complemented by results from model studies.

scholarly journals Voltage clustering in redox-active ligand complexes: mitigating electronic communication through choice of metal ion

2016 ◽  
Vol 45 (24) ◽  
pp. 9962-9969 ◽  
Author(s):  
Ryan A. Zarkesh ◽  
Andrew S. Ichimura ◽  
Todd C. Monson ◽  
Neil C. Tomson ◽  
Mitchell R. Anstey
Keyword(s):  
Energy Density ◽  
Transition Metals ◽  
Metal Ion ◽  
Electronic Communication ◽  
Main Group ◽  
Main Group Elements ◽  
Redox Active Ligand ◽  
Active Ligand ◽  
Redox Active

Homoleptic bis(imino)acenaphthene complexes of aluminum, chromium, and gallium were synthesized, characterized and modeled to compare the orbital contributions of main group elements and transition metals in ligand-based redox events toward increasing energy density of battery electrolytes.

Novel peptoids for the detection and suppression of reactive oxygen and nitrogen species

2003 ◽  
Vol 31 (6) ◽  
pp. 1302-1304 ◽  
Author(s):  
A.E.O. Fisher ◽  
D.P. Naughton
Keyword(s):  
Oxidative Stress ◽  
Metal Ion ◽  
Reactive Oxygen ◽  
Nitrogen Species ◽  
Reaction Products ◽  
Cupric Ion ◽  
Redox Active ◽  
Active Metal ◽  
Metal Ion Activation ◽  
Redox Active Metal

Novel peptoids useful for the detection and suppression of various components contributing to oxidative stress and for elucidation of the interplay between these species are presented. Oxidative stress involves redox-active metal ion activation/generation of RONS (reactive oxygen and nitrogen species). For detection of RONS, the peptoid probes consist of a conjugate designed to (1) complex redox-active and non-redox-active metal ions, and (2) differentiate between RONS based upon the reaction products following RONS attack on the probe. For suppression of RONS, subtle modifications in peptoid structure impart catalase and superoxide dismutase activities to the peptoids upon ferric or cupric ion complexation.

scholarly journals Controlling the redox properties of a pyrroloquinolinequinone (PQQ) derivative in a ruthenium(ii) coordination sphere

2015 ◽  
Vol 44 (7) ◽  
pp. 3151-3158 ◽  
Author(s):  
Hiroumi Mitome ◽  
Tomoya Ishizuka ◽  
Yoshihito Shiota ◽  
Kazunari Yoshizawa ◽  
Takahiko Kojima
Keyword(s):  
Coordination Sphere ◽  
Metal Ion ◽  
Reduction Potential ◽  
Reduction Process ◽  
Redox Properties ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Coordination Modes ◽  
Redox Active ◽  
The Stability

Difference in the coordination modes of pyrroloquinolinequinone (PQQ), a redox-active heteroaromatic cofactor, in ruthenium(ii) complexes, drastically affects the stability of the metal coordination and the reversibility of the reduction process of the PQQ ligand. Additional metal-ion binding to the PQQ ligand largely raises its 1e−-reduction potential.

scholarly journals Installation of internal electric fields by non-redox active cations in transition metal complexes

2019 ◽  
Vol 10 (43) ◽  
pp. 10135-10142 ◽  
Author(s):  
Kevin Kang ◽  
Jack Fuller ◽  
Alexander H. Reath ◽  
Joseph W. Ziller ◽  
Anastassia N. Alexandrova ◽  
...  
Keyword(s):  
Transition Metal ◽  
Electric Fields ◽  
Transition Metal Complexes ◽  
Metal Ion ◽  
Alkaline Earth ◽  
Computational Study ◽  
Earth Metal ◽  
Schiff Base Complexes ◽  
Alkaline Earth Metal ◽  
Redox Active

Experimental and computational study quantifying internal electric fields in synthetic systems using transition metal Schiff base complexes functionalized with a crown ether unit containing a mono- or dicationic alkali or alkaline earth metal ion.

Siderophore-redox active ionophore host-guest assemblies: A prototype for selective metal ion compartmentalization

2010 ◽  
Vol 363 (13) ◽  
pp. 3611-3615 ◽  
Author(s):  
Esther M. Tristani ◽  
Joseph I. Wirgau ◽  
George R. Dubay ◽  
John W. Sibert ◽  
Alvin L. Crumbliss
Keyword(s):  
Metal Ion ◽  
Redox Active
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