Polytriarylamines with On-Chain Crystal Violet Moieties

• Published in: Macromolecular rapid communications. 2009-05, Vol.30 (9-10), p.840-844
• Main Authors: Dumsch, Ines, Kudla, Christof J., Scherf, Ullrich
• Format: Article
• Language: English
• Subjects: crystal violet; polytriarylamines (PTAA); protonation; triphenylmethane dyes; UV-Vis spectroscopy
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.200800557

A novel polytriarylamine (PTAA)‐type alternating copolymer with on‐chain crystal violet moieties has been generated which shows the expected strong dependence of its UV‐Vis absorption spectrum from the pH value of the surrounding medium. Starting from the colorless leucocrystal violet form subsequent protonation/water elimination (by trifluoroacetic acid) leads to the formation of a blue colored, cationic copolymer with on‐chain crystal violet units that displays a characteristic Vis absorption band peaking at 627 nm. Further protonation leads to the generation of the corresponding dicationic species which is accompanied by a red shift of the long wavelength absorption maximum to 713 nm. The novel pH‐sensitive polytriarylamine derivatives will be investigated as potential p‐type semiconductors for OFET (gas) sensors. p‐Type semiconducting polymer materials with an intrinsic pH sensitivity are attractive for future OFET sensor applications. One promising class of such materials are soluble, alternating copolymers with on‐chain triarylmethane dyes that show a strong influence of the ambient pH value on their optical spectra.