Electroactive Twin Compounds Containing Trioxothioxanthene Electron Accepting Moieties RAMUNAS LYGAITIS, 1 JUOZAS VIDAS GRAZULEVICIUS, 1 VIOLETA VAITKEVICIENE, 2 AND VYGINTAS JANKAUSKAS 3 1 Department of Organic Technology, Kaunas University of Technology, Kaunas, Lithuania 2 Nuclear Engineering Laboratory, Lithuanian Energy Institute, Kaunas, Lithuania 3 Department of Solid State Electronics, Vilnius University, Vilnius, Lithuania Three dimeric molecules based on trioxothioxanthene and benzotriazole moieties were synthesized by alkylation and esterification reactions. The chemical structures of the compounds were confirmed by 1 HNMR, IR spectroscopies and mass spec- trometry. Dilute solutions of trioxothioxanthene and benzotriazole-based compounds in THF absorb electromagnetic radiation in the region of 230–320 nm. 1,10-Bis- (9,10,10-trioxothioxanthen-3-yl-carboxy)decane can be transformed into the glassy state with the glass transition temperature of 35  C. It is capable of transporting nega- tive charges. Electron drift mobility in the layers of trioxothioxanthene-based twin compound molecularly dispersed in PC-Z approaches 10 6 cm 2 =Vs at an electric field of 1  10 6 V=cm. Keywords Dimers; electron transport; trioxothioxanthene Introduction In contrast to numerous organic hole transport materials much less investigations have been done on organic electron–transporting materials [1]. One of the reasons for the lack of n-type semiconductors is the problem related to trapping. Since oxygen, a potential electron trap, is inevitably present, the reduction potential of the acceptor part of the molecule must be lower than that of oxygen. Therefore, stable under ambient conditions n-type semiconductors is of big interest. Previously we have reported on the synthesis and properties of bipolar molecules containing both electron acceptor and donor moieties. We have studied the charge and energy transport in the dilute solutions of one of 6-(9H-carbazole)hexyl 9,10,10-trioxo-9H- thioxanthen-3-oate [2,3]. In this work, we report on the synthesis and properties of Address correspondence to Juozas Vidas Grazulevicius, Department of Organic Technology, Kaunas University of Technology, Radvilenu Plentas 19, LT-3028, Kaunas, Lithuania. E-mail: Juozas.Grazulevicius@ktu.lt Mol. Cryst. Liq. Cryst., Vol. 535: pp. 189–195, 2011 Copyright # Taylor & Francis Group, LLC ISSN: 1542-1406 print=1563-5287 online DOI: 10.1080/15421406.2011.538339 189