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

• Type: Article in International Scientific Journal
• Date: 2001

Authors

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

Journal

Title: Chemistry - A European Journal

Vol. 7

Pages: 139-150

ISSN: 0947-6539

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 50 Citations

Scopus - 51 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12