Effect of water on excited‐state double proton transfer in 7‐azaindole‐H₂O complex: A theoretical study

Abstract

The dynamics of excited‐state double proton transfer (ESDPT) depending on hydrogen bonding of water molecules to the mediating water were studied at the TD‐M06‐2X/6‐31+G(d, p) level. The additional H‐bonding accepting (aW) or donating (dW) water had an effect on the mechanism of ESDPT. The double proton transfer occurred in an asynchronous but concerted protolysis or solvolysis pattern dependence on the aW or dW, respectively. The aW or dW stabilized the corresponding protolysis or solvolysis mechanism, respectively. The extra aW and dW would increase the asynchronicity of proton transfer. The bridging water in ESDPT process needed only one single H‐bond accepting or donating solvent molecule relying on the protolysis or solvolysis mechanism energetically. The specific vibrational modes in the 7AIW‐aW, 7AIW‐dW, and 7AIW‐aW‐dW complexes red‐shifted due to aW or dW.

Solvent‐polarity‐dependent excited‐state behaviors for 2‐(2‐hydroxyphenyl) benzothiazole‐5‐(9H‐carbazol‐9‐yl)phenol fluorophore: A theoretical study

“…Furthermore, as is well known, IR vibrational spectra should be a reasonable mean to ensure structural stability and to probe into hydrogen bonding interactions. [ 38–49 ] In this work, all the simulations about IR spectra for HBT‐Cz systems in solvents reveal that there are no imaginary frequencies for all the related structures. In addition, the IR vibrational frequencies of OH stretching vibrational mode involved in intramolecular OH···N of HBT‐Cz‐enol have been shown in Figure 2, which could provide the clear‐cut signature of excited‐state hydrogen bonding interactions.…”

“…Furthermore, as is well known, IR vibrational spectra should be a reasonable mean to ensure structural stability and to probe into hydrogen bonding interactions. [38][39][40][41][42][43][44][45][46][47][48][49] In this work, all the simulations about IR spectra for HBT-Cz systems in solvents reveal that there are no imaginary frequencies for all the related structures. In addition, the IR vibrational frequencies of O H stretching vibrational mode involved in intramolecular O HÁÁÁN of HBT-Czenol have been shown in Figure 2 226.78 cm À1 for TOL, 230.32 cm À1 for CCl 4 , and 240.53 cm À1 for HEX) between S 0 and S 1 states further reflects that large redshift resulting from low solvent polarity plays the more important role in facilitating excited state reaction for HBT-Cz system.…”

Unveiling the dehydrogenation mechanism of dihydrogen‐bonded phenol‐borane‐dimethylamine complex in the ground and excited states

“…[9,10] Over the years, there are numerous studies by theoretical as well as experimental methods to explore the hydrogen bonding interaction. [11][12][13][14][15][16][17][18][19][20][21] In general, hydrogen bonding can be defined as the interaction between a proton donor and proton acceptor atom (such as X-HÁÁÁY), and both proton donor and acceptor atoms are usually electronegative atoms. [22] For example, the pyridyl nitrogen, carbonyl oxygen, or azole-nitrogen group act as the acceptor of the proton, whereas the amino, hydroxyl, and occasionally pyrrolic groups serve as proton donor groups.…”

A theoretical study of solvent effect on the excited state intramolecular proton transfer of 3‐hydroxyflavone

“…[1] Since then, the ESIPT phenomenon has become a hot research field of many research groups. [2][3][4][5][6][7][8][9][10][11][12][13] Along with the deepening of research, people found that the ESIPT process was one of the most general and fundamental process in biological and chemistry systems. [14][15][16][17][18][19][20] The ESIPT has been widespread applied in many fields such as molecular sensors, molecular date storage, molecular switches, microenvironment probe, radiation hard scintillators, developments of ultraviolet stabilizers, and luminescent materials.…”