We herein report on an efficient synthesis of diacenaphthylene-fused benzo[1,2-b:4,5-b']dithiophenes and demonstrate that their packing structure in the solid state depends on the substituent groups. These compounds form dimers with their radical cations in high concentration solution and exhibit good field-effect mobility.

A series of fluorene derivatives end-capped with diphenylamino and oxadiazolyl were synthesized, and their photophysical and electrochemical properties are reported. Aggregation-induced emission (AIE) effects were observed for the materials, and bipolar characteristics of the molecules are favored with measurement of carrier mobility and calculation of molecular orbitals using density functional theory (DFT). Using the fluorene derivatives as emitting-layer, nondoped organic light-emitting devices (OLEDs) have been fabricated by spin-coating in the configuration ITO/PEDOT:PSS(35 nm)/PVK(15 nm)/PhN-OF(n)-Oxa(80 nm)/SPPO13(30 nm)/Ca(8 nm)/Al(100 nm) (n = 2-4). The best device with PhN-OF(2)-Oxa exhibits a maximum luminance of 14 747 cd/m(2), a maximum current efficiency of 4.61 cd/A, and an external quantum efficiency (EQE) of 3.09% in the blue region. Investigation of the correlation between structures and properties indicates that there is no intramolecular charge transfer (ICT) increase in these molecules with the increase of conjugation length. The device using material of the shortest conjugation length as emitting-layer gives the best electroluminescent (EL) performances in this series of oligofluorenes.

A novel two-dimensional organic semiconductor material [1]benzothieno[3,2-b][1]benzothieno[2,1-b:3,4-b':6,5-b'':7,8-b''']tetra(benzothiophene) (BTBTTBT) which largely extends the scope of the π-conjugated framework of heteroarene through "H" configuration was synthesized and its thermal, optical and electrochemical properties were investigated. This 2D molecule enables the easy growth of single-crystalline microribbons by the physical vapor transport method, which were evidenced by XRD, SEM and TEM. The single-crystalline OFET devices were fabricated based on the individual BTBTTBT microribbon and the remarkable high mobility of 17.9 cm(2) V(-1) s(-1) and on/off ratios of over 10(7) could be achieved.

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