| Nitric oxide, once thought of only as an environmental pollutant, has gained recognition as a biologically pertinent entity. It has been known that metalloporphyrins form relatively stable complexes with nitric oxide and are abundant in humans. Previous studies have revealed that many of these complexes release nitric oxide, to varying degrees, subsequent to photon absorption in the molecular ;In this study several nitrosylmetalloporphyrin complexes, both hydrophobic and hydrophillic, were made and characterized (TPPFe(II)NO ;The results indicated that the differences in the photoinduced denitrosylation yields are a direct manifestation of energy partitioning in the upper excited state deactivation pathway. Intersystem crossing essentially "wastes" some of the initial energy deposited in the system hence lowering the deligation yield. Only those molecules that deactivate via the charge transfer state lose NO. The actual deligation process is rate limited by the formation of the charge transfer state. |
