首页 | 本学科首页   官方微博 | 高级检索  
     


Influence of solvent and substituent on excited state characteristics of laser grade coumarin dyes
Authors:Sharma Vijay K  Saharo P D  Sharma Neera  Rastogi Ramesh C  Ghoshal S K  Mohan D
Affiliation:Department of Applied Physics, Guru Jambeshwar University, Haryana, Hisar, India. vijay_kumar_sharma@hotmail.com
Abstract:Absorption and fluorescence emission of 4 and 7 substituted coumarins viz. C 440, C 490, C 485 and C 311 have been studied in various polar and non-polar organic solvents. These coumarin dyes are substituted with alkyl, amine and fluorine groups at 4- and 7-positions. They give different absorption and emission spectra in different solvents. The study leads to a possible assignment of energy level scheme for such coumarins including the effect on ground state and excited state dipole moments due to substitutions. Excited state dipole moments of these dyes are calculated by solvetochromic data experimentally and theoretically these are calculated by PM 3 method. The dipole moments in excited state, for all molecules investigated here, are higher than the corresponding values in the ground state. The increase in dipole moment has been explained in terms of the nature of excited state and resonance structure.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号