The electron attachment effect on the structure and properties of orto-hydroxyaryl Schiff and Mannich bases – hydrogen/proton transfer processes

2021 ◽  
Author(s):  
Jerzy Jański ◽  
Szczepan Roszak ◽  
Kazimierz Wladyslaw Orzechowski ◽  
Lucjan Sobczyk
Keyword(s):  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Electron Attachment ◽  
Mannich Bases ◽  
Biological Processes ◽  
Structure And Properties ◽  
Intramolecular Hydrogen Bonds ◽  
Transfer Processes ◽  
Intramolecular Hydrogen

The attachment of electrons is known to significantly influence some chemical and biological processes. The chemical differences between Schiff and Mannich bases characterized by strong intramolecular hydrogen bonds, result from...

Effect of amino group on the excited-state intramolecular proton transfer (ESIPT) mechanisms of 2-(2′-hydroxyphenyl)benzoxazole and its amino derivatives

RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 5134-5140 ◽  
Author(s):  
Chaozheng Li ◽  
Yonggang Yang ◽  
Chi Ma ◽  
Yufang Liu
Keyword(s):  
Excited State ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Intramolecular Proton Transfer ◽  
Amino Group ◽  
Electronic Density ◽  
Intramolecular Hydrogen Bonds ◽  
Amino Derivatives ◽  
Intramolecular Hydrogen

The electronic density redistributes and it migrates in opposite directions for HBO when compared to those of 5A-HBO and 6A-HBO. The amino group in the HBO framework can change the behavior of the intramolecular hydrogen bonds.

Elaborating a new excited state intramolecular proton transfer (ESPT) mechanism for a new π-conjugated dye 2, 2′-((5-(2-(4-methoxyphenyl)ethenyl)-benzene-1,1-diyl)-bis-(nitrilomethylylidene)-diphenol)

2018 ◽  
Vol 96 (3) ◽  
pp. 351-357 ◽  
Author(s):  
Dapeng Yang ◽  
Min Jia ◽  
Xiaoyan Song ◽  
Qiaoli Zhang
Keyword(s):  
Hydrogen Bond ◽  
Excited State ◽  
Charge Transfer ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Density Functional ◽  
Dynamical Behavior ◽  
Intramolecular Proton Transfer ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen

In this work, the excited state dynamical behavior of a novel π-conjugated dye 2,2′-((5-(2-(4-methoxyphenyl)ethenyl)-benzene-1,1-diyl)-bis-(nitrilomethylylidene)-diphenol) (C1) has been investigated. Two intramolecular hydrogen bonds of C1 are tested to pre-existing in the ground state via AIM and reduced density gradient. Using a time-dependent density functional theory (TDDFT) method, it has been substantiated that the intramolecular hydrogen bonds of C1 should be strengthened in the S1 state via analyzing fundamental bond length, bond angles, and corresponding infrared vibrational modes. The most obvious variation of these two hydrogen bonds is the O4–H5···N6 bond, which might play important roles in excited state behavior for the C1 system. Furthermore, based on electronic excitation, charge transfer could occur. Just due to this kind of charge re-distribution, two hydrogen bonds should be tighter in the first excited state, which is consistent with the variation of hydrogen bond lengths. Thus, the phenomenon of charge transfer is reasonable evidence for confirming the occurrence of the excited state proton transfer (ESPT) process in the S1 state. Our theoretically constructed potential energy surfaces of C1 show that excited state single proton transfer should occur along with the O4–H5···N6 hydrogen bond rather than the O1–H2···N3 bond. We not only clarify the ESIPT mechanism for C1 but put forward new affiliation and explain a previous experiment successfully.

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