Rhenium- and technetium-oxo corroles: Toward corrole-based drugs and radiopharmaceuticals.

Abstract

Corroles are an important class of contracted porphyrin analogues. Since quasi-one-pot syntheses of corroles were first reported in 1999, their coordination chemistry has been extensively studied.

In the course of this thesis, the “periodic table of corroles” has been extended by two new elements, rhenium and technetium. Except from an accidental synthesis of an ReVO corrole via ring contraction of a porphyrin, no Re corroles were known prior to this work. As part of this thesis, I have developed the first rational synthesis of Re corroles, based on oxidative metalation of meso-triarylcorroles with Re2(CO)10 in refluxing decalin. A total of 9 ReVO complexes, have been made, including 5 that were structurally characterised. I also prepared the first 99-technetium corroles using [NEt4]2[99TcCl3(CO)3] as the 99Tc source; one of these complexes was structurally characterized.

The ReVO corroles were found to exhibit near-IR phosphorescence at room temperature, with long triplet lifetimes ~60 s, but low quantum yields ~2.9%. Furthermore, two amphiphilic ReVO corroles exhibited strong cytotoxicity against AY27 rat bladder cancer cells and WiDr human colon cancer cells under blue light illumination.

My hope is that the work presented here will pave the way toward 99mTc corroles and other metallocorroles as new metallodrugs and radiopharmaceuticals.