A caged nicotine with nanosecond range kinetics and visible light sensitivity

We report the synthesis, characterization and applications of a ruthenium–bipyridine based caged nicotine. The complex [Ru(bpy)2(nic)2]2+ (where bpy = 2,2′ bipyridine and nic = nicotine (3-[(2S)-1-methylpyrrolidin-2-yl] pyridine)) releases nicotine with a quantum yield ϕ = 0.23 upon irradiation with biologically harmless, blue (473 nm) or green (532 nm) light. The photolysis reaction is clean and very fast, with a time constant of 17 ns. The synthesis is simple and the obtained compound is characterized by NMR, UV-Vis spectroscopy and cyclic voltametry. We find that this compound is active in biological systems, being able to elicit action potentials in leech neurons.

Graphical AbstractRuthenium–bipyridyl complex delivers nicotine after visible light irradiation and causes neuronal firing.Figure optionsDownload as PowerPoint slide