Synthesis of tetrathiafulvalene-containing zirconium(IV) pincers and metallocavitands for hosting fullerenes
摘要:
The synthesis and spectroscopic characterization of zirconium(IV) dicarboxylate 1 and metallocavitand 2 are described. Encapsulation studies of fullerenes C-60 and C-70 were performed using UV-Vis spectroscopy in chlorobenzene, toluene, benzene, carbon disulfide and in a mixture of toluene/dichloromethane. UV-Vis titrations have shown that the binding abilities of the hosts toward fullerene C-70 are considerably higher than those obtained for fullerene C-60. (C) 2014 Elsevier B.V. All rights reserved.
Synthesis, electropolymerization and oxidation kinetics of an anthraquinone-functionalized poly(3,4-ethylenedioxythiophene)
摘要:
The chemical synthesis of an EDOT derivative endowed with an electron acceptor anthraquinone moiety (AQ-EDOT) is described. The electrochemical polymerization of the monomer has been studied by cyclic voltammetry, chronoamperometry and chronopotentiometry. The monomer oxidation-polymerization takes places on platinum at potentials more positive than 1.3V vs. Ag/AgCl. The polymer film presents a stable redox process with E-0 = 0.22V, that can be assigned to the characteristic exchange process of the parent unsubstituted PEDOT polymer. An unstable redox process at E-0 = -1.00V, present decreasing charges on the consecutive cycles despite that the lost reduction charge is recovered by two irreversible oxidation processes taking place at high anodic potentials 0.00 and 0.16V. A structural charge trapping effects occurring by reduction at -1.1V and re-oxidation at 0.16V of the anthraquinone moiety is suggested. The stable redox process is not affected by cycling allowing the obtention of the oxidation empirical kinetics, kinetic coefficients and reaction orders. Different initial states attained by reduction at different cathodic potentials for a constant time were explored for the kinetic study. (C) 2009 Elsevier Ltd. All rights reserved.