摘要
The electronic structures and optical properties of oligothiophene substituted spirofluorenes are investigated theoretically with semi-empirical quantum chemical calculations. A theoretical investigation of the interaction between two perpendicular π-systems of various oligothiophene substituted spirofluorenes is conducted. The results demonstrate that the interaction be- tween two perpendicular branches is reduced by oligothiophene substitutions. Photoexcitation induced relaxation is mainly located on one of the equivalent branches or the branch with longer conjugation length. In addition to these benefits brought by 9,9-spirobifluorene center, the specific oligothiophene moieties linked to the spirt center also have properties of significant merit, such as the ability to tune energy levels and emission colors by controlling the conjugation length.
The electronic structures and optical properties of oligothiophene substituted spirofluorenes are investigated theoretically with semi-empirical quantum chemical calculations. A theoretical investigation of the interaction between two perpendicular π-systems of various oligothiophene substituted spirofluorenes is conducted. The results demonstrate that the interaction between two perpendicular branches is reduced by oligothiophene substitutions. Photoexcitation induced relaxation is mainly located on one of the equivalent branches or the branch with longer conjugation length. In addition to these benefits brought by 9,9-spirobifluorene center, the specific oligothiophene moieties linked to the spiro center also have properties of significant merit, such as the ability to tune energy levels and emission colors by controlling the conjugation length.
基金
financially supported by the National Basic Research Program of China (Grant No. 2009CB930601)
the National Natural Science Foundation of China (Grant Nos. 20804020, 60976019, 50903028 and 20974046)
the Program for New Century Excellent Talents in University (Grant No. NCET-07-0446)
the Scientific and Technological Innovation Teams of Colleges and Universities in Jiangsu Province (Grant No. TJ207035)
the Scientific Research Foundation of Nanjing University of Posts and Telecommunications (Grant No. NY210017)
