• 中文核心期刊要目总览
  • 中国科技核心期刊
  • 中国科学引文数据库(CSCD)
  • 中国科技论文与引文数据库(CSTPCD)
  • 中国学术期刊文摘数据库(CSAD)
  • 中国学术期刊(网络版)(CNKI)
  • 中文科技期刊数据库
  • 万方数据知识服务平台
  • 中国超星期刊域出版平台
  • 国家科技学术期刊开放平台
  • 荷兰文摘与引文数据库(SCOPUS)
  • 日本科学技术振兴机构数据库(JST)

吩噻嗪衍生物的分子内电荷转移激发态的特性

Properties of the Intramolecular Excited Charge-Transfer States of Donor-Acceptor Phenothiazine Derivatives

  • 摘要: 合成了一系列的N-10位取代的吩噻嗪给体受体化合物,这些受体包括苯、苯甲醚、吡啶、萘、苯乙酮和苯乙腈.研究了不同极性溶剂中这些化合物的分子内的光诱导电荷转移现象.稳态荧光的溶剂化效应和较大的Stokes位移清楚表明,仅仅后四种吩噻嗪衍生物的激发态存在着分子内的电荷转移,而苯和苯甲醚取代吩噻嗪因为受体部分氧化电势低,所以不具有这种特性.修正过的Lippert-Mataga公式被用来分析Stokes位移值,从而获得激发态偶极矩.较大的激发态偶极矩说明在激发态时这四种给体受体化合物体系内发生了完全的电子转移.氧化还原电势的数据表明基态时这四种衍生物给体受体部分的作用比较弱.分析荧光光谱获得的结果说明伴随着电荷转移这四种衍生物的激发态构型变化比较小,给体和受体间的扭转角在电荷转移后的激发态与在基态时相似.

     

    Abstract: A series of N-bonded donor-acceptor derivatives of phenothiazine containing benzene (PHPZ), anisole (ANPZ), pyridine (PYPZ), naphthalene (NAPZ), acetophenone (PEPZ), and benzonitrile (BNPZ) as an electron acceptor was synthesized. Their photophysical properties were investigated in solvents of different polarities by absorption and emission techniques. These studies clearly reveals the existence of an intramolecular charge transfer (ICT) excited state in the latter four compounds. The solvent dependent Stokes shift values were analyzed by the modified Lippert-Mataga equation to obtain the excited state dipole moment values. The large excited state dipole moment suggests that the full electron transfer takes place in the A-D systems. The obtained values of redox potentials indicate that both subunits of all the A-D molecules studied interact very weakly in the ground states. The results obtained from the analysis of the CT fluorescence spectra confirm that the small conformational changes accompanying excited state charge transfer, the twist angle between the donor and acceptor moieties in the excited 1CT state seems to be similar to that in the ground state.

     

/

返回文章
返回