摘要： 2+ composed of 2,5- di(2- thienyl)- N- 2+ and 2 Stable conjugated oligomer dications 1 methylpyrrole (DTP) units at the both ends of the π- systems with methoxy substitu- ents at the 3- position of thienyl units and methylthio end- capping group and benzo[2,1- b:3,4- b′]dithiophene (BDT) unit(s) at the central part with sterically de- manding phenyl substituents were synthesized. From DFT calculations and ESR ex- 2+ was reduced periments, it was concluded that the diradical character in 1 in comparison with the radical character of their reference compound 3·+ composed 2+ was considered to have a of one DTP and one BDT units. In addition, the shorter 1 2+. Nevertheless, judging from the re- further lower diradical character than that of 2 2+ showed a comparable π- 2+ and 2 sults of VT- UV- vis- NIR measurements, both 1 dimerization ability at the DTP moiety in dichloromethane solution with 3·+.