Studies On Oxidative Polymerization Of Thiophene Derivatives

In this paper, three types of polyterthiophene derivatives (Poly[3',4'-ethylenedioxy- 2,2':5',2"-terthiophene](PTET), Poly[5,7-dithien-2-yltHieno-[3,4-b]pyrazine] (PTP T) , Poly[2, 2': 5', 2"-terthiophene](PTT))were synthesized by oxidative polymeriza- tion with different Fe3+oxidants (Fe(ClO4)3, FeCl3, Fe2(SO4)3), the effects of different oxidants on the structures and propertities of the polymers were studied; poly[2, 2'- bithiophene](PBT)was synthesized by oxidative polymerization and organometallic polycondensation, and the effects of different chemical polymerization methods on the structures and propertities of the PBT were studied; the effects of different Fe(ClO4)3 concentrations, reaction times and temperatures on the structures and propertities of the four types of polythiophene derivatives were studied. The main results are summarized as follows:1. Three types of polyterthiophene derivatives (Poly[3',4'-ethylenedioxy-2,2':5',2"-terthiophene(]PTET), Poly[5,7-dithien-2-yltHieno-[3,4-b]pyrazine](PTPT), Poly [2, 2': 5', 2"-terthiophene](PTT),) were synthesized by oxidative polymerization with different Fe3+oxidants (Fe(ClO4)3, FeCl3, Fe2(SO4)3), which demonstrated good electroactivities. Results showed that PTET and PTPT had better properties while Fe(ClO4)3 was used as an oxidant, PTT gived better properties with FeCl3 oxidant.2. The effects of different Fe(ClO4)3 concentrations, reaction times and temperatures on the structures and propertities of the PTET, PTPT were studied; the effects of different reaction times and temperatures on the structures and propertities of the PTT were studied with FeCl3 oxidant. Results showed that three types of polyterthiophene derivatives had better properties while mole ratio of monomer and oxidant was 1: 4, for 12 h of reaction time at 18℃. The conductivities of PTET, PTPT, PTT were 1.47, 1.95×10-2 , 7.89×10-4 S/cm, the specific capacitances were 133, 115, 98 F/g respectively.3. The neutral and doped poly[2, 2'-bithiophene](PBT)were synthesized by organometallic polycondensation and oxidative polymerization respectively, and the effects of different chemical polymerization methods on the structures and propertities of the PBT were studied. PBT had better structural regularity synthesized by organometallic polycondensation, but showed low degree and bad electroactivity. PBT gived longestπ-conjugation lengths and better electroactivity synthesized by oxidative polymerization, the conductivity was 0.17 S/cm, and the specific capacitance was 133 F/g while mole ratio of TET and Fe(ClO4)3 was 1: 4.