Excited-state Intramolecular Proton-transfer-induced Charge Transfer of Polyquinoline

被引：12

作者：

Park, Sun-Young ^{[1
]}

Jeong, Hyeok ^{[1
]}

Yu, Hyunung ^{[1
]}

Park, Soo Young ^{[2
]}

Jang, Du-Jeon ^{[1
]}

机构：

[1] Seoul Natl Univ, Sch Chem, Seoul, South Korea

[2] Seoul Natl Univ, Dept Mat Sci & Engn, Seoul, South Korea

来源：

PHOTOCHEMISTRY AND PHOTOBIOLOGY | 2010年 / 86卷 / 06期

基金：

新加坡国家研究基金会;

关键词：

TRANSFER DYNAMICS; COUPLED PROTON; HYDROGEN-BOND; ELECTRON; FLUORESCENCE; EMISSION; ACID; PRINCIPLE;

D O I：

10.1111/j.1751-1097.2010.00797.x

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The excited-state intramolecular proton-transfer-induced charge transfer of semirigid polyquinoline (PQH) is explored in 1,1,2,2-tetrachloroethane (TCE) and N-methyl-2-pyrrolidinone (MP) using picosecond time-resolved fluorescence spectroscopy. Reaction mechanisms are found to depend on the rotational conformations of PQH at the moment of excitation; whereas the trans-enolic form does not undergo intramolecular proton transfer within its excited-state lifetime, the cis-enolic form does within 15 ps to form a tautomeric zwitterion species. While the subsequent intramolecular charge transfer of the zwitterionic species to yield a tautomeric keto species takes place on time scales of 25 ps in TCE (epsilon = 8.50) and 62 ps in MP (epsilon = 32.55), its reverse reaction is also followed on time scales of 28 ps in TCE and 20 ps in MP. The lack of a kinetic isotope effect in both forward and reverse charge-transfer reactions support our proposed mechanisms.

引用

页码：1197 / 1201

页数：5

共 42 条

[1] Excited-state intramolecular proton transfer via a preexisting hydrogen bond in semirigid polyquinoline [J].