Effects of Hydrogen Bonding on Tuning Photochemistry: Concerted Hydrogen‐Bond Strengthening and Weakening

Wagging motion of hydrogen-bonded wire in the excited-state multiple proton transfer process of 7-hydroxyquinoline·(NH3)3 cluster

“…However, little is known about electronic excited-state hydrogen bond, because the structure and dynamics of which are difficult to analyze for both theoretical and experimental studies. Recently, Zhao and Han [12][13][14][15][16][17][18][19] have determined theoretically that intermolecular hydrogen bonds between solute and alcoholic molecules can be significantly strengthened in the electronic excited state upon photoexcitation. In previous works [20][21][22][23], we have demonstrated that, the excited-state hydrogen bonding behavior would play an important role in many photochemical reactions such as fluorescence quenching [20], excited-state proton transfer [21], tuning effects on photochemistry [22].…”

A theoretical forecast of the hydrogen bond changes in the electronic excited state for BN and its derivatives

“…2). This summing-up has been confirmed in numerous systems, through studying their electronic excited-state hydrogenbonding dynamics using both experimental and theoretical methods [40][41][42][43][44][45][46][47][48][49][50]. For example, the electronic excitation energy of the hydrogen bonded FN-MeOH complex shifts to red in the S 1 state compared to that of the monomer fluorenone (FN).…”

“…Recently, the relationship between electronic spectral shifts and electronic excited- * E-mail: haoce_dlut@126.com state hydrogen-bonding dynamics has been illustrated by Zhao and Han for the first time. This relation is central to understanding hydrogen-bonding dynamics [40]. Zhao and Han, in discussing the geometric structures of the hydrogen-bonded complex thiocoumarin-methanol (TC-MeOH) in different electronic states, showed that the hydrogen bond C=S· · · H-O is significantly weakened in the electronically excited S 1 , S 2 , and T 1 states.…”

Hydrogen-bonding study of photoexcited 4-nitro-1,8-naphthalimide in hydrogen-donating solvents

“…Experiments performed using the femtosecond time-resolved vibrational spectroscopy have shown the potential to monitor hydrogen-bonding dynamics. Hydrogen-bonding dynamics always occurs on ultrafast timescales, which plays an increasingly important role in many photophysical processes and photochemical reactions [41][42][43][44][45][46][47][48][49][50][51][52][53]. It has been confirmed by Zhao et al that the intermolecular hydrogen bond in many molecular systems is greatly strengthened in the electronically excited state.…”

“…It has been confirmed by Zhao et al that the intermolecular hydrogen bond in many molecular systems is greatly strengthened in the electronically excited state. Electronic excite-state hydrogen bond strengthening is closely linked with many ultrafast radiationless deactivation processes, such as ultrafast internal conversion(IC) [43] and intersystem crossing (ISC) [41], vibrational energy relaxation (VER) [54], twisted intramolecular charge transfer(TICT) [47] and intermolecular photoinduced electron transfer (PET) [45].…”