title: Charge Transfer Through Dithieno[2,3-a:3',2'-c]phenazine: Effect of Substitution Pattern on the Optoelectronic Properties of Regioisomeric Luminophores.
abstract: Two series of regioisomeric luminophores that contained a dithieno[2,3-a:3',2'-c]phenazine (DTP) unit as an electron acceptor have been designed and synthesized. To investigate the effect of substitution pattern on the optoelectronic properties of these luminophores, electron donors (N,N-dihexylaniline or N,N-dihexyl-4-vinylaniline) were incorporated at the 2,5-, 8,11-, and 9,10-positions of the DTP unit. We found that the optoelectronic properties of the regioisomeric luminophores were greatly affected by the substitution pattern: functionalization at the 8,11-positions of the DTP unit was superior to the other two substitution patterns in extending the effective π-conjugation and strengthening the intramolecular charge-transfer interactions. Moreover, the insertion of vinyl groups between the DTP and N,N-dihexylaniline units narrowed the energy band-gap for isomers 4 and 5. However, hypsochromically shifted absorption and photoluminescence maxima were observed for isomeric luminophore 6, in which electron donors were substituted at the 2,5-positions of the DTP unit. These results should facilitate greater understanding of the structure-property relationships in regioisomeric semiconductors and present a new way to design optoelectronic materials with effective substitution patterns.
authors.affiliation: Lab of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai, 200438, P. R. China.
authors.forename: Yijing
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Lab of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai, 200438, P. R. China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Lu
authors.affiliation: Lab of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai, 200438, P. R. China.
authors.forename: Chunlan
authors.initials: C
authors.lastname: Xiang
authors.affiliation: Lab of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai, 200438, P. R. China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ling
authors.affiliation: Lab of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai, 200438, P. R. China. zhougang@fudan.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
keywords: charge transfer; donor-acceptor systems; heterocycles; luminescence; phenazines