Ultrafast Excited-State Dynamics of a Cyano-Substituted “Proton Sponge”

The dynamics of a substituted proton sponge—the 1,8-bis(dimethylamino)-4-cyanonaphthalene (DMAN-CN) molecule—was investigated after excitation in the S1 state. Experimental and theoretical information are reported. The former includes absorption, fluorescence, and time-resolved transient absorption spectra, which were recorded in solution. Real-time dynamics measurements were also performed on gas-phase isolated DMAN-CN. TD DFT/6-31G(d,p) level and CIS/6-31G(d,p) excited-state calculations complement these results. This has allowed revisiting the energy transfer process between a locally excited (LE) and a charge transfer (CT) state, which is often invoked with this kind of molecule.