title: Carbon-Nanotube-Mediated Electrochemical Transition in a Redox-Active Supramolecular Hydrogel Derived from Viologen and an l-Alanine-Based Amphiphile.
abstract: A two-component hydrogelator (16-A)2 -V(2+) , comprising an l-alanine-based amphiphile (16-A) and a redox-active viologen based partner (V(2+) ), is reported. The formation the hydrogel depended, not only on the acid-to-amine stoichiometric ratio, but on the choice of the l-amino acid group and also on the hydrocarbon chain length of the amphiphilic component. The redox responsive property and the electrochemical behavior of this two-component system were further examined by step-wise chemical and electrochemical reduction of the viologen nucleus (V(2+) /V(+) and V(+) /V(0) ). The half-wave reduction potentials (E1/2 ) associated with the viologen ring shifted to more negative values with increasing amine component. This indicates that higher extent of salt formation hinders reduction of the viologen moiety. Interestingly, the incorporation of single-walled carbon nanotubes in the electrochemically irreversible hydrogel (16-A)2 -V(2+) transformed it into a quasi-reversible electrochemical system.
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560012, Karnataka, India.|Director's Research Unit (DRU), Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India.
authors.forename: Sougata
authors.initials: S
authors.lastname: Datta
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560012, Karnataka, India. sb@orgchem.iisc.ernet.in.|Director's Research Unit (DRU), Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India. sb@orgchem.iisc.ernet.in.|Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560 064, Jakkur, India. sb@orgchem.iisc.ernet.in.
authors.forename: Santanu
authors.initials: S
authors.lastname: Bhattacharya
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000737:chemistry*; D004563:Electrochemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D037742:Nanotubes, Carbon; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D000409:Alanine
keywords: charge transfer; cyclic voltammetry; nanocomposite; redox-active hydrogel; self-assembly