Electrostatic Association of Ammonium-Functionalized Layered-Transition-Metal Dichalcogenides with an Anionic Porphyrin.

Ammonium-modified MoS2 and WS2 were prepared and characterized by complementary spectroscopic, thermal, and microscopic means. The positive charges on functionalized MoS2 and WS2, due to the presence of ammonium units, were exploited to electrostatically bring in contact an anionic porphyrin bearing a carboxylate moiety, yielding porphyrin/MoS2 and porphyrin/WS2 ensembles, 5a and 5b, respectively. Efficient photoluminescence quenching of porphyrin's emission by MoS2 and WS2 within nanoensembles 5a and 5b, in combination with time-resolved photoluminescence assays, revealed transduction of energy from the photoexcited porphyrin to MoS2 or WS2.