Synthesis And Optical/Electrochemical Properties Of Polythiophene Derivatives With Push-Pull Electronic Structures

Organic photovoltaic materials with low cost and other advantages has attracted much attention in the field of polymer solar cells.The synthesis of new organic photovoltaic materials has become an important direction to improve photoelectric conversion efficiency of organic solar cells.The push-pull electronic structure of polythiophene derivatives have unique optical / electrochemical properties,so it has important application in solar cell materials.In this paper,we synthesized a series of the push-pull electronic structure of polythiophene derivatives materials,main research contents of this paper are as follows(1)Seven monomers were designed and synthesized.The seven compounds were 5-Bromo-[2,2’]bithiophenyl(S1),4,7-Bis-[2,2’]bithiophenyl-5-yl-benzo[1,2,5]thiadiazole(S2),4,7-Bis-(5’-bromo-[2,2’]bithiophenyl-5-yl)-benzo[1,2,5]thiadiazole(S3),9-Hexyl-2,7-bis-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-9,9a-dihydro-4aH-carbazole(S4),1,3-Dibromo-5-oct yl-thieno[3,4-c]pyrrole-4,6-dione(S5),1,3-Bis-[2,2’]bithiophenyl-5-yl-5-octyl-thieno[3,4-c]pyr role-4,6-dione(S6)and1,3-Bis-(5’-bromo-[2,2’]bithiophenyl-5-yl)-5-octyl-thieno[3,4-c]pyrrole-4,6-dione(S7),and we got them by Suzuki coupling reaction and still coupling reaction.(2)Six kinds of polymers were designed and synthesized.Poly(5-Bromo-[2,2’]bithiophenyl-4,7-Bis-[2,2’]bithiophenyl-5-yl-benzo[1,2,]thiadiazole)(P1)and Poly(1,3-Bis-[2,2’]bithiophenyl-5-yl-5-octyl-thieno[3,4-c]pyrrole-4,6-dione)(P4)are formed by the redox polymerization of monomer S2 and S6,and Poly(4-(5’-Benzo[1,2,5]thiadiazol-4-yl-[2,2’]bithiophenyl-5-yl)-7-[2,2’]bithiophenyl-5-yl-benz o[1,2,5]thiadiazole)(P2),Poly(7-[5’-(7-[2,2’]Bithiophenyl-5-yl-benzo[1,2,5]thiadiazol-4-yl)-[2,2’]bithiophenyl-5-yl]-9-hexyl-9,9a-dihydro-4aH-carbazole)(P3),Poly(1-(5’-Benzo[1,2,5]thiadi azol-4-yl-[2,2’]bithiophenyl-5-yl)-3-[2,2’]bithiophenyl-5-yl-5-octyl-thieno[3,4-c]pyrrole-4,6-d ione)(P5)andPoly(3-[2,2’]Bithiophenyl-5-yl-1-[5’-(9-hexyl-8a,9-dihydro-4b H-carbazol-2-yl)-[2,2’]bithiophenyl-5-yl]-5-octyl-thieno[3,4-c]pyrrole-4,6-dione)(P6)are all synthesized by Suzuki reactionAll monomers characterized by IR,1H NMR,13 C NMR.For ploymers,ultraviolet-visible(UV)absorption spectrum,fluorescence spectrum(FL)were measured to study the optical properties;Thermal properties is studied by differential thermal curve(DSC)and thermogravimetric curve(TGA),molecular weight was measured by liquid gel chromatograph and electrochemical properties were studied by testing cycle volt-ampere curve.