Masashi Mamada

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Polycyclic benzimidazole derivatives, an important class of compounds in organic electronics and photovoltaics, were prepared using a solvent-free "green" process based on heating carboxylic acid anhydrides and arylene diamines in the presence of zinc acetate in the solid state. Products were isolated and purified directly by train sublimation of the crude(More)
Crystals of the title compound (DBTTF), C(14)H(8)S(4), feature a triclinic polymorph different from two known monoclinic polymorphs. In this form, there are two independent centrosymmetric half-mol-ecules in the asymmetric unit. Although the mol-ecular orientations are relatively similar to one of monoclinic polymorphs, the packing motif is different.
Anthra[2,3-b]thieno[2,3-d]thiophene (ATT), which is readily accessed from thieno[3,2-b]thiophene and 2,3-naphthalenedicarboxylic anhydride, allows for selective substitution at the terminal thiophene ring, thereby providing asymmetric monoalkyl and monoalkylthienyl thienoacenes. Alkyl-substituted ATT (CnATT, n = 6, 8, 10, 12) has characteristics of a p-type(More)
Quinones are promising moieties for n-type organic semiconductors due to their high electron affinity. Benzo[1,2-b:4,5-b']dithiophene-4,8-dione derivative with a quinone moiety have been synthesized, characterized, and used as active layer of organic field-effect transistors (OFETs). This derivative has deep LUMO level, leading to efficient charge-carrier(More)
Ultrathin electronic circuits that can be manufactured by using conventional printing technologies are key elements necessary to realize wearable health sensors and next-generation flexible electronic devices. Due to their low level of power consumption, complementary (CMOS) circuits using both types of semiconductors can be easily employed in wireless(More)
Isomerically pure syn-/anti-anthradithiophene derivatives have been developed in the past few years. Although anti-isomers showed higher field-effect mobilities than mixture of isomers have been reported, a detailed comparison of syn-isomer and anti-isomer molecules has not been carried out. In this study, we took newly synthesized pure unsubstituted(More)
A series of new benzimidazole derivatives were synthesized by the solid-state condensation and direct sublimation (SSC-DS) method and their physical properties were investigated. The reaction yields and product stability were significantly affected by the identity of the diamine and anhydride substituents. On the other hand, the substituents of the(More)
The benchmark of soluble organic semiconductors based on acenes is the 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-PEN). However TIPS-PEN still suffers from photoinduced oxidation due to its low degree of aromaticity. Increasing the aromaticity while keeping similar optical and electrochemical properties as well as a shape suitable for good hole(More)
Isomerically pure syn-/anti-isomers of 2,8-dimethylanthradithiophene (DMADT) were synthesized in five steps and characterized using thermogravimetry, X-ray single crystal analysis, UV-vis absorption, and electrochemical measurements. The physical properties in solution were slightly different for each isomer, whereby the more obvious differences were(More)