Unusual coordination environment for barium cations in ion recognition conducting poly[Ni(salen)(receptor)] films

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Tedim, J (Author) Other; Bessada, R (Author) Other; Patricio, S (Author) Other; Magalhaes, AL (Author) FCUP; Freire, C (Author) FCUP; Gurman, SJ (Author) Other; Hillman, AR (Author) Other

Journal

Title: Langmuir

Vol. 24 No. 16

Pages: 8998-9005

ISSN: 0743-7463

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 22 Citations

Scopus - 22 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-003-WZ8

DOI: 10.1021/la801424k

Abstract (EN): [Ni(salen)] complexes bearing different crown ether receptors were electropolymerized to give films whose voltammetric signatures responded to Ba(2+). In line with DFT calculations, X-ray absorption spectroscopy (XAS) near the Ni K-edge showed the nickel local environment in the monomers and their corresponding polymers (in the presence or absence of barium) to be identical. However, the expectation of crown size-dependent barium local environment (based on geometry,and donor atom availability) was not found. XAS near the Ba K-edge showed that Ba(2+) in the films coordinated to only two oxygen donors, irrespective of crown size. This surprisingly low coordination number (compared to solution species) is accompanied by a higher barium/crown ratio than the anticipated 1: 1 stoichiometry. The implications of these effects for design and performance of sensors based on metal ion recognition chemistry are discussed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8