[meso-Tetra(pentafluorophenyl)porpholactonato]Pt(II) (1  ), was recently shown to possess optical base-sensitive capabilities in the range from pH 11 to 13. Exposure of 1   to high pH values dramatically red shifts the UV-vis spectrum of this chromophore from ?max of 574 nm to a ?max of 708 nm, making it a unique optical pH probe. This shift is caused by nucleophilic attack of the OH-/alkoxide onto the lactone moiety of the macrocycle. We present here the synthesis and characterization of porpholactones with varying central metal ions, meso-aryl-substituents, and �-substituents, such as 2  and 3  , that exhibit sensitivity at dynamic pH ranges different from that of 1  . Specifically, the susceptibility of the nucleophilic attack can be influenced by modifying the electron density around the porphyrin ring with electron withdrawing �-nitro substituents, in an attempt to shift the pH-sensing profile to weakly basic pH values. We present their utilization as optical pH sensors, including their fluorescence spectra. The sensing compounds were evaluated in aqueous solutions as well as embedded in polymer matrixes for testing as optical fiber-based optodes.

<i>meso</i>-Tetraarylnitroporpholactones: Tuning the pH range for optical high pH sensing

243rd National Meeting (2012)

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meso-Tetraarylnitroporpholactones: Tuning the pH range for optical high pH sensing