The objective of this research is to synthesize and characterize CORM complexes with thiosemicarbazone ligand groups. For the past 20 years, carbon monoxide has been studied as a potential biological agent. Carbon monoxide is able to easily bind to proteins such as myoglobin and is a key signaling factor in many systems in the body in low doses. Carbon monoxide releasing molecules (CORMs) have been investigated as complexes that can release controlled doses of CO to particular targets in the body. Ruthenium complexes derived from CORM-2 and manganese complexes from Mn(CO)5Br were used in this study, with the ligand varying in the functional group attached to the amine. The ligands used were a series of N-alkyl-substituted 6-nitropiperonal thiosemicarbazones; alkyl = methyl, ethyl or phenyl. We will report on the synthesis and characterization of the complexes fac-Mn(CO)3(TSC)Br or fac-Ru(CO)3(TSC)Cl by many techniques including elemental analysis, NMR, infrared, cyclic voltammetry and electronic spectroscopy. The CO-releasing properties of the Mn-complexes, evaluated by the myoglobin assay will also be reported. The Mn-complexes are photo-CORMs in that they rapidly release CO when irradiated with light. The half-lives of the complexes range from 8.4 s to 92.3 s depending on the wavelength of light used to irradiate the complex (365, 405 or 435 nm). Each complex releases different amounts of CO. An example of this is that the unsubstituted thiosemicarbazone releases 1.9, 1.6 and 1.1 equivalent of CO when irradiated with 365 nm, 405 nm and 435 nm light respectively. Antimicrobial activities of the complexes against common bacteria will also be reported.

Synthesis and characterization of ruthenium and manganese CORM complexes with thiosemicarbazone ligands

255th National Meeting (2018)

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