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Titolo:
Salicylate-selective membrane electrodes based on Sn(IV)- and O=Mo(V)-porphyrins: differences in response mechanism and analytical performance
Autore:
Malinowska, E; Niedziolka, J; Rozniecka, E; Meyerhoff, ME;
Indirizzi:
Warsaw Univ Technol, Fac Chem, Dept Analyt Chem, PL-00664 Warsaw, Poland Warsaw Univ Technol Warsaw Poland PL-00664 Chem, PL-00664 Warsaw, Poland Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA Univ Michigan Ann ArborMI USA 48109 , Dept Chem, Ann Arbor, MI 48109 USA
Titolo Testata:
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
fascicolo: 1-2, volume: 514, anno: 2001,
pagine: 109 - 117
Fonte:
ISI
Lingua:
ENG
Soggetto:
SINGLE HYDROXO BRIDGE; METALLOPORPHYRIN DERIVATIVES; ANION CARRIER; POTENTIOMETRIC SELECTIVITY; TETRAPHENYLPORPHYRIN; THIOCYANATE; PERCHLORATE; IONOPHORES; COMPLEXES; CHLORIDE;
Keywords:
salicylate-selective electrodes; anion selectivity; oxomolybdenum(V) and tin(IV) porphyrins; dimer-monomer equilibrium;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
45
Recensione:
Indirizzi per estratti:
Indirizzo: Malinowska, E Warsaw Univ Technol, Fac Chem, Dept Analyt Chem, Noakowskiego 3, PL-00664 Warsaw, Poland Warsaw Univ Technol Noakowskiego 3 Warsaw Poland PL-00664 d
Citazione:
E. Malinowska et al., "Salicylate-selective membrane electrodes based on Sn(IV)- and O=Mo(V)-porphyrins: differences in response mechanism and analytical performance", J ELEC CHEM, 514(1-2), 2001, pp. 109-117

Abstract

The potentiometric response characteristics (slope and selectivity) of salicylate-selective electrodes based on Sn(IV) and O=Mo(V) (oxomolybdenum) tetraphenylporphyrins (TPP) in o-nitrophenyloctylether plasticized poly(vinylchloride) membranes are compared. Super-Nernstian salicylate responses (slopes > -100 mV decade(-1)) are observed for membranes doped with Sn(IV)[TPP]Cl-2 and 10-30 mol% of a lipophilic tetraphenylborate derivative (sodium bis[trifluoromethyl]phenylborate, NaTFPB). The borate derivative is requiredto optimize potentiometric selectivity for salicylate over other anions inaccordance with existing theory for charged carrier type anion selective ionophores. The super-Nernstian response of Sn(IV) porphyrin doped membranesis shown, via UV-vis spectroscopy, to result from spontaneous formation ofhydroxide ion bridged porphyrin dimers in the membrane phase., which are converted to monomeric porphyrin upon increasing the concentration of salicylate in the sample solution. In contrast. the salicylate response of the membranes doped with O = Mo(V)[TPP]OEt are Nernstian (-56 to 60 mV decade(-1)), even in the presence of added borate derivative to optimize salicylate selectivity, UV-vis spectroscopic studies of the membranes doped with the molybdenum species confirm the absence of dimer formation, which correlates well with the conventional Nernstian response behavior of such membranes. Electrodes formulated with the optimized membranes containing O=Mo(V)[TPP]OEtand the borate derivative (10-35 mol%) are shown to exhibit high selectivity for salicylate over many anions, even lipophilic anions such as perchlorate (log K-pot less than or equal to -2.5). (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 11:52:49