3,3”-Dihexyl-2,2’:5’,2”-terthiophene

For the preparation of PAT (n = 1,6, 8,12) and of poIy(3-cyanothiophene) with high yields, a zero-valent nickel complex is also used [266]. Hexyl substituted oligo(thiophene)s (number of thiophene rings 6,9,12,15) can be prepared by the Ni(0)-catalyzed coupling reaction of a 5,5"-dibromo-3,3"-dihexyl-2,2 5, 2"-terthiophene) [572, 573]. PT derivatives having alkyloxy substituents at 3 positions are synthesized by dehalogenation polycondensation of the corresponding 2,5-dibromothiophene derivatives with zero-valent nickel complexes [247],... 

Fig. 28.26 Normalized UV intensities vs. normalized IR intensities for two poly(3,3"-dihexyl-2,2 5, 2"-terthiophene) samples FeCN doped and heated, respectively, (a) at 97°C and (b) at 1(X)°C. (From Ref 218.)...

Figure 7.2. X-ray diffraction pattern of poly(3,3"-dihexyl-terthiophene), ref 101, (John Wiley Sons Inc.).

Polythiophenes substituted regioregularly with alkyl chains were prepared by the polymerization of alkylated bithiophenes and terthiophene. Souto et al. polymerized 3,3 -dihexyl-2,2 -bithiophene (41) with iron(III)... 

Trihexyl-2,2 5, 2"-terthiophene 196 was similarly prepared, but by Stille-type cross-coupling reactions [177], In this reaction sequence, the less effective step is the Pd(0)-catalyzed coupling of the organotin thiophene and 2-bromo-3-hex-ylthiophene to yield 3,4 -dihexyl-2,2 -bithiophene 163 in only 23%. Bromination of the latter and reaction with the stannylated thiophene under Stille-conditions results in 69% yield of the desired regioregular terthiophene 196 [Eq. (57)]. 

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