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Porpholactones are porphyrinoids in which one or more β,β'-bonds of the parent chromophore were replaced by lactone moieties. Accessible to varying degrees by direct and nonselective oxidations of porphyrins, the rational syntheses of all five dilactone isomers along stepwise, controlled, and high-yielding routes via porphyrin → tetrahydroxyisobacteriochlorin metal complexes → isobacteriochlorindilactone metal complexes or porphyrin → tetrahydroxybacteriochlorin → bacteriochlorindilactone (and related) pathways, respectively, are described. A major benefit of these complementary routes over established methods is the simplicity of the isolation of the dilactones because of the reduced number of side products formed. In an alternative approach we report the direct and selective conversion of free base meso-tetrakis(pentafluorophenyl)porphyrin to all isomers of free base isobacteriodilactones using the oxidant cetyltrimethylN + MnO 4 - . The solid-state structures of some of the isomers and their precursors are reported, providing data on the conformational modulation induced by the derivatizations. We also rationalize computationally their differing thermodynamic stability and electronic properties. In making new efficient routes toward these dilactone isomers available, we enable the further study of this diverse class of porphyrinoids.

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.

The results of an electrospray ionization (ESI(+) and ESI(-)) collision-induced fragmentation investigation of meso-tetrakis(heptafluoropropyl)porphyrin (T(F)HP) are reported. The fragmentation patterns of T(F)HP show, in both ionization modes, the formation of fragments with direct covalent meso-alkyl-to-beta-linkages on elimination of HF. In addition, in the ESI(+) mode, the losses of perfluoroalkyl radicals are observed. A detailed analysis of the fragmentation patterns allows conclusions to be drawn on the identification of the fragment species. Comparable cyclized products were previously produced using radical-initiated solution-phase syntheses. The results presented will help to analyze meso-perfluoroalkyl-derivatized porphyrinic macrocycles that are becoming increasingly popular.