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.

scholarly journals Role of intramolecular hydrogen bonding in the excited-state intramolecular double proton transfer (ESIDPT) of calix[4]arene: A TDDFT study

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 602-609 ◽  
Author(s):  
Se Wang ◽  
Zhuang Wang ◽  
Ce Hao
Keyword(s):  
Hydrogen Bonding ◽  
Excited State ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Ground State ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonds ◽  
Double Proton Transfer ◽  
Intramolecular Hydrogen

AbstractThe time-dependent density functional theory (TDDFT) method was performed to investigate the excited-state intramolecular double proton transfer (ESIDPT) reaction of calix[4]arene (C4A) and the role of the intramolecular hydrogen bonds in the ESIDPT process. The geometries of C4A in the ground state and excited states (S1, S2 and T1) were optimized. Four intramolecular hydrogen bonds formed in the C4A are strengthened or weakened in the S2 and T1 states compared to those in the ground state. Interestingly, upon excitation to the S1 state of C4A, two protons H1 and H2 transfer along the two intramolecular hydrogen bonds O1-H1···O2 and O2-H2···O3, while the other two protons do not transfer. The ESIDPT reaction breaks the primary symmetry of C4A in the ground state. The potential energy curves of proton transfer demonstrate that the ESIDPT process follows the stepwise mechanism but not the concerted mechanism. Findings indicate that intramolecular hydrogen bonding is critical to the ESIDPT reactions in intramolecular hydrogen-bonded systems.

Excited state intramolecular proton transfer in amino 2-(2′-hydroxyphenyl)benzazole derivatives: Effects of the solvent and the amino group position

2007 ◽  
Vol 126 (2) ◽  
pp. 728-734 ◽  
Author(s):  
Fabiano Severo Rodembusch ◽  
Fernando Paulus Leusin ◽  
Leandra Franciscato Campo ◽  
Valter Stefani
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Intramolecular Proton Transfer ◽  
Amino Group ◽  
Group Position
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