title: meso-Tetraarylporpholactones as high pH sensors.
abstract: The ability of meso-tetra(pentafluorophenyl)porpholactone (T(F)PL) and its Pt(II) complex [meso-tetra(pentafluorophenyl)porpholactonato]Pt(II) (T(F)PLPt) to function as optical high pH sensors is described. Under strongly alkaline or high methoxide conditions, their UV-vis spectra undergo dramatic and reversible red-shifts. The dynamic range for the sensor T(F)PLPt in solution is from pH 11.5 to 13.2. Using (1)H, (19)F, and (13)C NMR, UV-vis and IR spectroscopy, mass spectrometry, and the use of model compounds, the molecular origin of this optical shift is deduced to be a nucleophilic attack of OH(-)/MeO(-) on the lactone carbonyl of the chromophore, representing a novel mechanism for porphyrin-based sensors. The sensing compound was solubilized with Cremophor EL for use in aqueous solutions and embedded in polymer matrixes for testing as optical fiber-based optodes and planar sheet optode materials.
authors.affiliation: Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA. gamalk@u.washington.edu
authors.forename: Gamal E
authors.initials: GE
authors.lastname: Khalil
authors.forename: Pedro
authors.initials: P
authors.lastname: Daddario
authors.forename: Kimberly S F
authors.initials: KS
authors.lastname: Lau
authors.forename: Sayed
authors.initials: S
authors.lastname: Imtiaz
authors.forename: Michelle
authors.initials: M
authors.lastname: King
authors.forename: Martin
authors.initials: M
authors.lastname: Gouterman
authors.forename: Alexey
authors.initials: A
authors.lastname: Sidelev
authors.forename: Narissa
authors.initials: N
authors.lastname: Puran
authors.forename: Masoud
authors.initials: M
authors.lastname: Ghandehari
authors.forename: Christian
authors.initials: C
authors.lastname: Brückner
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D009944:Organoplatinum Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry*; D005464:Fluorobenzenes; D005466:Fluorocarbons
chemical_list: D009944:Organoplatinum Compounds; D011166:Porphyrins; C554137:meso-tetra(pentafluorophenyl)porpholactone; D005464:Fluorobenzenes; D005466:Fluorocarbons