Fundamental coordination chemistry of metalloporphyrins with sulfur-containing small molecules

Hydrogen Sulfide (H2S) has become a molecule of interest over the last few decades due to its observed biological activity. One area of interest is the ability of H2S to interact with metalloproteins, specifically hemeproteins, in both vertebrates and invertebrates. In similar fashion to carbon monoxide (CO) and nitric oxide (NO), H2S has been implicated as being an important signaling molecule. Unlike CO and NO, H2S has only begun to recently be studied and there is still much to learn about its basic modes of action in biological systems. This work concentrates on elucidating the fundamental chemistry regarding H2S at heme centers by way of synthetic models. A number of structural models of thiolate-bound iron porphyrinates have been synthesized and characterized and are reported herein. Using both ferric and ferrous systems, the reaction chemistry and stabilities of these biomimetic models are investigated. Along with iron, both gallium and manganese porphyrinates were investigated in hopes to provide further insight into H2S-heme chemistry.