Green-Light-Induced PhotoCORM: Lysozyme Binding Affinity towards Mn^I and Re^I Carbonyl Complexes and Biological Activity Evaluation

Reaction of N-(2-pyridylmethylene)benzene-1,4-diamine (L) with [MBr(CO)₅] (M = Mn^I and Re^I) affords complexes of the type [MBr(CO)₃L] [M = Mn^I (1) and Re^I (2)]. Complex 1 releases CO upon illumination with light in the range of 525–468 nm. No photo induced CO release is detected from 2. Reactive azide complex 3, obtained by bromide's ligand exchange, reacts with the electron-poor alkyne dimethyl acetylene dicarboxylate giving triazolato complex 4 ([Mn(triazolate^COOMe,COOMe)(CO)₃L]) via the free catalyst [3+2] cycloaddition coupling. Complex 1 exhibits interesting antifungal activity (MIC = 30 nM) against Candida albicans and Cryptococcus neoformans as well as cytotoxic activity of 12.56 µg/mL against noncancerous human embryonic kidney cells. Reactivity of the complexes towards hen egg white lysozyme is studied by electrospray ionization mass spectrometry.