No abstract

The synthesis of 2, 3, 7, 8, 12, 13, 17, 18-octabromo-meso-tetrakis(2-pyridyl)porphyrin, H 2 Br 8 T2PyP, is described, including the comparison of four attempted methods for the demetallation of ZnBr 8 T2PyP. One of the methods represents a strategy of demetallation based on the acid-base properties of the macrocycle, the solvent-dependent kinetics of metal insertion into porphyrins and the pH-dependent solubility of the 2-pyridylporphyrin derivatives in water. Self-coordinating aggregation of ZnBr 8 T2PyP in non-coordinating solvents was verified by 1 H NMR spectroscopy. The Mn(III)/Mn(II) redox potential for MnBr 8 T2PyPCl is 0.38 V higher than the reduction potential measured for its first-generation analogue, MnT2PyPCl. Cyclohexane hydroxylation by iodosylbenzene was performed in CH 3 CN catalyzed by MnBr 8 T2PyPCl and MnT2PyPCl. MnBr 8 T2PyPCl was highly active, even at low concentration (5 x 10 -5 M), but perhalogenation did not account for oxidative robustness. At such a low catalyst concentration, MnT2PyPCl exhibited no activity as inferred by comparison to blank experiments.

No abstract

No abstract

No abstract