A Combined Electrochemical Quartz-Crystal Microbalance Probe Beam Deflection (EQCM-PBD) Study of Solvent and Ion Transfers at a Poly[Ni(saltMe)]-Modified Electrode During Redox Switching

Abstract

The oxidative polymerisation of the complex2,3-dimethyl-N,N′-bis(salicylidene)butane-2,3-diaminatonickel(II), [Ni(saltMe)], was monitored by the electrochemical quartz microbalance (EQCM) and crystal impedance techniques. Polymerisation efficiency was maintained throughout deposition of a film, which behaved rigidly, on the electrode. A combined EQCM-PBD (probe beam deflection) study of the redox process of the film exposed to a monomer-free solution of 0.1 M tetraethylammonium perchlorate (TEAP) in acetonitrile showed an electroneutrality mechanism dominated by anion movement accompanied by co-transfer of solvent above 0.8 V. The individual contributions of all the mobile species involved in the redox switching of the poly[Ni(saltMe)] film were determined quantitatively by temporal convolution analysis; the estimated solution-phase diffusion coefficient of the exchanged species was 1.24×10−5 cm2 s−1.