A two-step electron-driven proton transfer mechanism for the solution-phase nonradiative decay process of squaraine molecule

- PESs of electron-driven proton transfer processes of SQ-DMA are calculated.
- SQ-DMA works as an efficient photobase in the first EDPT process.
- The first EDPT process shows a nonadiabatic tunneling transition between LE and CT.
- Arrhenius type temperature dependence is due to the Marcus type electron transfer.