Spectroelectrochemical characterisation of poly[Ni(saltMe)]-modified electrodes

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

Vilas Boas, M (Autor) Outra; Freire, C (Autor) FCUP; de Castro, B (Autor) FCUP; Christensen, PA (Autor) Outra; Hillman, AR (Autor) Outra

Revista

Título: Chemistry - A European Journal

Vol. 7

Páginas: 139-150

ISSN: 0947-6539

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 50 Citações

Scopus - 51 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-000-WNP

DOI: 10.1002/1521-3765(20010105)7:1<139::aid-chem139>3.3.co;2-h

Abstract (EN): Electrogenerated polymers based on the nickel(II) complex 2,3-dimethyl-N,N'-bis (salicylidene)butane-2,3 diaminatonickel(II), poly[Ni(saltMe)], were characterised by in situ FTIR and UV/Vis spectroscopy and ex-situ EPR spectroscopy in order to gain insights into film structure, electronic states and charge conduction. The role of the nickel ions during film oxidation was probed by using EPR to study naturally abundant Ni and Ni-61-enriched polymers. The data from all the spectroscopic techniques are consistent, and clearly indicate that polymerisation and redox switching are associated with oxidative ligand based processes; coulometry suggests that one positive charge was delocalised through each monomer unit. EPR provided evidence for the non-direct involvement of the metal in polymer oxidation: the polymer is best described as a polyphenylene-type compound (conducting polymer), rather than an aggregation of nickel complexes (redox polymer), and the main charge carriers are identified as polarons. An explanation for the high electrochemical stability and conductivity of poly[Ni(saltMe)] with respect to that of poly[Ni(salen)] is proposed, based on stereochemical repulsion between monomeric units; this can impose a less compact supramolecular structure on polymers with bulkier substituents.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 12