Photoinduced coupled twisted intramolecular charge transfer and excited-state proton transfer via intermolecular hydrogen bonding: A DFT/TD-DFT study

- The DFT/TD-DFT investigation on the photoinduced coupled TICT and ESPT.
- The ESPT is induced by the intermolecular hydrogen-bond strengthening.
- The early occurred TICT facilitates the ESPT.
- The coupling of TICT and ESPT is energetically preferable.
- A verification calculation is performed at the CC2/def-TZVP level.