Poly 3,6-carbazolylene s

Poly(3,6-carbazolylene)s are the most readily accessible polymers of carbazole and are readily synthesized starting from carbazole. In order to obtain solubility, an alkyl group must be attached at the nitrogen. The synthesis of... 

Whereas the previous two classes of polymers can be synthesized starting from carbazole, the monomers for poly(2,7-carbazolylene)s 2,7-dihalocarbazoles such as the dibromide 8, have to be made by total synthesis. The most efficient... 

Some doubts have been raised about the electrochemical stability of poly(2,7-carbazolylene)s due to the high electron density at the free 3- and 6-positions, making oxidation at these sites facile and leading to possible crosslinking or... 

One obvious way to get around the problem of oxidation at the 3- and 6-positions in poly(2,7-carbazolylene)s is to substitute these sites. If this is done in a single-stranded polymer, sterie interaetion between the substituents on adjacent units would cause torsion of the backbone with loss of conjugation, producing blue shifts in absorption and emission and also reduction in chain packing and charge-carrier mobilities. This can be overcome by making doubly stranded ladder-type polymers 23, as shown in Scheme 6.8. Acylation of the... 

Several attempts have been made to overcome the problems with metastable TPD and TAPC glasses. Recently we described the synthesis of 3,6-bis[(9-hexyl-3-carbazolyl)ethy-nyl]-9-hexylcarbazole 27, a trimeric model compound of poly(carbazolylene ethynylene) [15], This material shows a glass transition temperature of 41 °C and forms glasses which are stable for more than a year. Mobilities up to 10 cm A s ( = 6 10 V/cm, T = 30 °C) have been measured by the time-of-flight technique. 

Linear poly(A/-methyl-3,6-carbazolylen) (64c) has been prepared by the reaction of 3,6-dibromo-9-methylcarbazole (67a) with the Grignard reagent (67b) in the presence of a complex nickel catalyst [436-438], A brittle film of (67c) can be cast from nitrobenzene solution which shows a conductivity, when doped with I2 or NOBF4, as high as 6 S cm . Doping with iodine induces a postpolymerization reaction which increases its molecular weight and improves mechanical stability. 

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