Synthesis of extended thiophene systems: materials for electronical and optical applications
1998 (English)Doctoral thesis, monograph (Other scientific)
In this thesis the synthesis and some material properties ofdifferent extended thiophene systems have been studied. One ofthe areas studied is the synthesis of methyl- and methylthiosubstituted dithienothiophene donors and their abilities toform cation radieal- and charge transfer salts. It was foundthat they were poor candidates showing low tendency to formCrystals of good quality. The conductivities measured oncompressed pellets were found to be in the order of 10-6- 10-2S/cm. The crystal structure of one of the cationradieal salts, (2,3,5,6-tetramethyldithieno[3,2-b:2',3'd]thiophene)2PF6was solved and showed clearly how the bulkymethylgroups prevent close packing in the Crystals explainingthe low conductivity ( 10-6S/cm2). Attempts to synthesize the correspondingbis(ethylenedichalcogen)dithienothiophenes to achieve betterCrystal packing have so far been unsuccessful, but resulted inuseful building blocks, (2,3-ethylenedithio)thiophene ED'IT,and (1,4-thioxano)thiophene TOT, for end-capped oligomers.Starting from EDTT and TOT, series of end-cappedoligomers bEDTnT and TOnT were synthesized. They were found toform stable cation radieals and showed red-shifted UV-VISabsorptions.In an attempt to make LED-devices with enhancedefficiencies, a new serie of heteroatom substituted monomersfor polythiophenes was synthesized.
Place, publisher, year, edition, pages
Stockholm: Kemi , 1998. , 66 p.
Trita-IOK, ISSN 1100-7974 ; 48
IdentifiersURN: urn:nbn:se:kth:diva-2708ISBN: 99-2778893-2OAI: oai:DiVA.org:kth-2708DiVA: diva2:8411
NR 201408052000-01-012000-01-01Bibliographically approved