摘要
在钯催化剂条件下,2-(4-溴苯基)-1-苯基-1H-苯并咪唑(PPBI-Br)和吩噁嗪(PXZ)反应合成新型分子PPBIPXZ。采用核磁和质谱表征PPBI-PXZ的结构,紫外-可见光谱和荧光发射光谱探究其光物理性质,热重分析其热稳定性。量化计算结果表明:PPBI-PXZ分子的最高已占有轨道(HOMO)主要分布在供体PXZ部分,最低未占有轨道(LUMO)则分布在受体PPBI部分,供体和受体间的二面角达87.0°,电荷转移量0.891,S1态与T1态能级差计算值为0.28eV。在正己烷、甲苯、乙酸乙酯、二氯甲烷和乙腈5种极性递增的溶剂中,PPBI-PXZ在370nm附近出现吸收肩峰,其最大发射波长从419nm红移至577nm。这种显著的溶致变色现象展现了扭曲分子的分子内电荷转移(TICT)的特征。
A new compound（PPBI-PXZ）was synthesized by the reaction of 2-（4-bromophenyl）-1-phenyl-1H-benzimidazole（PPBI-Br）with phenoxazine（PXZ）using apalladium catalyst.The compound was characterized by NMR and MS.Photophysical properties were investigated by UV-Vis and emission spectra.Thermal stability was determined by thermogravimetric analysis.The results of quantum chemistry calculation showed that the electron density of the HOMO state was localized on PXZ unit,while corresponding LUMO state was mainly distributed on PPBI unit.The dihedral angle between the PXZ and PPBI was 87.0°.The charge transfer amount（q）was 0.891.The calculated energy gap between the lowest singlet state（S1）and the lowest triplet state（T1）was 0.28 eV.In n-hexane,toluene,ethyl acetate,dichloromethane and acetonitrile,PPBI-PXZ solutions had an absorption shoulder around 370 nm and emitted light with maximum wavelengths from 419 nm to 577 nm.The obvious solvatochromism demonstrated the nature of intramolecular charge transfer of twisted molecule.
出处
《化工新型材料》
CAS
CSCD
北大核心
2015年第7期137-139,142,共4页
New Chemical Materials
基金
福州大学科技发展基金资助项目(2010XQ02)
关键词
吩噁嗪
苯并咪唑
分子内扭曲电荷转移
溶致变色
量化计算
phenoxazine
benzimidazole
twisted intramolecular charge transfer
solvatochromism
quantum chemistry calculation
