TY - JOUR

T1 - Multielectron redox processes in polymeric cobalt complexes with N2O2 Schiff base ligands

AU - Novozhilova, Maria

AU - Smirnova, Evgenia

AU - Polozhentseva, Julia

AU - Danilova, Julia

AU - Chepurnaya, Irina

AU - Karushev, Mikhail

AU - Малев, Валерий Вениаминович

AU - Timonov, Alexander

N1 - Funding Information: This work was partially supported by the Russian Foundation for Basic Research (Grant № 18-03-00545-a ). Scanning electron microscopy studies were performed at the Interdisciplinary Resource Center for Nanotechnology (St. Petersburg State University Research Park).

PY - 2018/8/20

Y1 - 2018/8/20

N2 - A series of polymeric cobalt (II) complexes with tetradentate N2O2 Schiff base ligands (poly-[Co(Schiff)]) are prepared via oxidative electrochemical polymerization and characterized by scanning electron microscopy, cyclic voltammetry, quartz crystal microgravimetry, and in situ UV/Vis spectroscopy in inert atmosphere. Integration of data from all techniques revealed that (a) all studied poly-[Co(Schiff)] films demonstrate multi-electron redox switching between 0 V and +1.4 V (vs. Ag/AgCl); (b) the Co(II) to Co(III) conversion takes place in the early stage of polymer oxidation, which is followed by both one- and two-electron ligand-based redox processes in the later stages; (c) the number of electrons exchanged by each monomer unit during oxidation/reduction of the polymer depends on the substituents in the imine bridge and aldehyde moieties of the ligand, as well as on the donor number of the electrolyte solvent. The poly-[Co(CH3O-SaltmEn)] film demonstrates the ability to be reversibly oxidized by three electrons per a monomer unit in an acetonitrile-based electrolyte, which makes it a viable candidate for energy storage applications.

AB - A series of polymeric cobalt (II) complexes with tetradentate N2O2 Schiff base ligands (poly-[Co(Schiff)]) are prepared via oxidative electrochemical polymerization and characterized by scanning electron microscopy, cyclic voltammetry, quartz crystal microgravimetry, and in situ UV/Vis spectroscopy in inert atmosphere. Integration of data from all techniques revealed that (a) all studied poly-[Co(Schiff)] films demonstrate multi-electron redox switching between 0 V and +1.4 V (vs. Ag/AgCl); (b) the Co(II) to Co(III) conversion takes place in the early stage of polymer oxidation, which is followed by both one- and two-electron ligand-based redox processes in the later stages; (c) the number of electrons exchanged by each monomer unit during oxidation/reduction of the polymer depends on the substituents in the imine bridge and aldehyde moieties of the ligand, as well as on the donor number of the electrolyte solvent. The poly-[Co(CH3O-SaltmEn)] film demonstrates the ability to be reversibly oxidized by three electrons per a monomer unit in an acetonitrile-based electrolyte, which makes it a viable candidate for energy storage applications.

KW - Electrochemical polymerization

KW - Multielectron redox process

KW - N O Schiff base ligand

KW - Poly-[Co(Schiff)]

KW - Polymeric cobalt (II) complex

KW - N2O2 Schiff base ligand

KW - SALEN-TYPE LIGANDS

KW - MODIFIED ELECTRODES

KW - PLATINUM

KW - NI(SALEN)

KW - CONDUCTING POLYMERS

KW - FILMS

KW - NICKEL

KW - ELECTROCHEMICAL-BEHAVIOR

KW - SPECTROELECTROCHEMICAL CHARACTERIZATION

KW - ACETONITRILE

UR - http://www.scopus.com/inward/record.url?scp=85048570667&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/multielectron-redox-processes-polymeric-cobalt-complexes-n2o2-schiff-base-ligands

U2 - 10.1016/j.electacta.2018.06.030

DO - 10.1016/j.electacta.2018.06.030

M3 - Article

VL - 282

SP - 105

EP - 115

JO - Electrochimica Acta

JF - Electrochimica Acta

SN - 0013-4686

ER -