Excited-State Dynamics in a Dyad Comprising Terpyridine-Platinum(II) Ethynylene Linked to Pyrrolidino-[60]Fullerene

A hybrid [Pt(tBu3terpy)(C≡C—Ph—C60)]+ complex (Pt−Fu) wherein a phosphorescent platinum center is linked to fullerene has been prepared using a copper(I)-promoted cross-coupling reaction. The electrochemical and spectroscopic properties were understood in light of the properties of the isolated building blocks and references compounds, Pt and Fu. In particular, in Pt−Fu, the electrochemical studies revealed that the first reduction process is fullerene-based and that the lowest-energy Pt+−Fu− charge-separated (CS) state lies in the range 2.0−2.1 eV. The luminescence properties of the investigated species have been monitored in a CH2Cl2 solvent at room temperature and in a MeOH/EtOH (1:4 v/v) glassy solution at 77 K. Upon excitation at 450 nm at room temperature and in air-free solvent, Pt displays an intense luminescence of 3MLCT nature, with λmax = 605 nm (523 nm at 77 K, corresponding to 2.37 eV), ϕem = 0.013, and τem = 920 ns. Under the same conditions, Fu exhibits the typical 1C60 fluorescence, with λ...