Synthesis and Coordination of a Tripodal Ligand Bearing Nitrogen (N) and Sulfur (S) Donors and its Reactivity with Low Valent Transition Metals
Jose Martinez*, Margarita Gonzales and Pradip Mascharak
Although the toxicity of carbon monoxide (CO) is well established, this gaseous molecule is endogenously produced via the oxidation of heme by heme oxygenase. Once viewed as a toxic byproduct, CO in recent years has been found to confer anti-inflammatory, antiapoptotic, cytoprotective and vasorelaxing activity at low concentrations. This biological significance of CO prompted our research group to synthesize photo-induced CO-releasing molecules (CORM’s) as a means of controlled CO delivery for therapeutic use.
The project involves synthesis, characterization and photo activity of the resulting transition metal carbonyls. To tune the light activated CO release, we designed a tripodal ligand, (2-quinolylmethyl)-[2’-(methylthio)phenyl]amine (qmtpa), bearing nitrogen and sulfur donors. The coordinating ability of qmtpa with low valent transition metals such as Mn(I) and Ru(II) will be examined. The resulting complexes will be characterized by absorption spectroscopy , Infrared spectroscopy (IR) and myoglobin assay. These methods will allow us to determine the light absorption parameters and CO-releasing properties of the resulting complexes. The photosensitivity of our resulting compounds will indicate the possibility of their use as CORM’s for therapeutic applications given that the release of CO occurs upon illumination.