Effect of benzene ring on the excited-state intramolecular proton transfer mechanisms of hydroxyquinoline derivatives,Journal of Physical Organic Chemistry

当前位置： X-MOL 学术 › J. Phys. Org. Chem. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Effect of benzene ring on the excited-state intramolecular proton transfer mechanisms of hydroxyquinoline derivatives
Journal of Physical Organic Chemistry ( IF 1.9 ) Pub Date : 2021-06-14 , DOI: 10.1002/poc.4257
Feng Zhang ₁ , Jing Zhao ₁ , Chaozheng Li ₂

Affiliation

The proton transfer process of 8-hydroxyquinoline (HQ) can occur from the hydroxy oxygen to the pyridine nitrogen through a five-membered ring. For 10-hydroxybenzo[h]quinolone (HBQ), the proton transfer process occurs through a six-membered ring due to the insertion of a benzene ring between phenol and pyridine. In this work, the proton transfer processes of the five-membered (HQ) and six-membered (HBQ) ring hydroxyquinoline hydrogen bond systems were studied through theoretical methods. The geometric parameters and infrared (IR) vibrational spectra analysis show that the insertion of a benzene ring between phenol and pyridine affect the strength of the intramolecular hydrogen bond (O─H···N). Upon photoexcitation, the electron density is redistributed, which can provide driving force for the proton transfer processes. The potential barrier of the excited-state intramolecular proton transfer (ESIPT) process for HQ is 3.05 kcal/mol, whereas the ESIPT process of HBQ is barrierless. It is demonstrated that the proton transfer process of HBQ is easier than that of HQ in S₁ state. The proton transfer process of HQ can only occur in S₁ state, whereas that of HBQ can occur in the ground state (S₀) and S₁ state. In addition, the analysis of the nonadiabatic dynamics simulations reveals that the ESIPT process of HBQ (26 fs) is faster than that of HQ (53 fs). To sum up, the insertion of a benzene ring between phenol and pyridine affect the strength of the intramolecular hydrogen bond (O─H···N) and then affect the proton transfer processes to some extent.

中文翻译：

苯环对羟基喹啉衍生物激发态分子内质子转移机制的影响

8-羟基喹啉 (HQ) 的质子转移过程可以通过五元环从羟基氧到吡啶氮发生。对于 10-羟基苯并[ h]喹诺酮 (HBQ)，由于苯环在苯酚和吡啶之间插入，质子转移过程通过六元环发生。在这项工作中，通过理论方法研究了五元（HQ）和六元（HBQ）环羟基喹啉氢键系统的质子转移过程。几何参数和红外(IR)振动光谱分析表明苯酚和吡啶之间插入苯环会影响分子内氢键(O─H…N)的强度。在光激发时，电子密度重新分布，这可以为质子转移过程提供驱动力。HQ 的激发态分子内质子转移 (ESIPT) 过程的势垒为 3.05 kcal/mol，而 HBQ 的 ESIPT 过程是无障碍的。₁状态。HQ的质子转移过程只能发生在S ₁态，而HBQ的质子转移过程可以发生在基态（S ₀）和S ₁态。此外，非绝热动力学模拟的分析表明，HBQ (26 fs) 的 ESIPT 过程比 HQ (53 fs) 快。综上所述，苯酚和吡啶之间插入苯环会影响分子内氢键（O─H…N）的强度，进而在一定程度上影响质子转移过程。

更新日期：2021-06-14

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11