Browsing by Author "Chou, Hsiao-Chieh"

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Regio- and stereo-selective [4+4] photodimerization of angular-shaped dialkyltetracenedithiophene
(2019-01-11)
Hsu, Tze-Gang
;
Chou, Hsiao-Chieh
;
Liang, Ming-Ju
;
Lai, Yu-Ying
;
Cheng, Yen-Ju
Angular-shaped dialkyltetracenedithiophenes (aTDTs) undergo [4+4] photodimerization in solution to form a butterfly-shaped skeleton. This reaction proceeds in a regio- and stereo-selective manner, forming only a single planosymmetric syn-[2,2]-daTDT out of six possible products. The photocycloaddition of aTDTs can take place topochemically in the thin-film state while maintaining regio- and stereo-selectivity. Stronger aliphatic dispersion forces and - interactions play important roles in forming the eclipsed dimeric complex that leads to the syn-[2,2]-daTDT isomer.
Synthesis and Isomeric Effects of Ladder-Type Alkylated Terbenzodithiophene Derivatives
(2016-03-18)
Chen, Yung-Lung
;
Hsu, Jhih-Yang
;
Lin, Fang-Yu
;
Lai, Yu-Ying
;
Chou, Hsiao-Chieh
A new class of heptacyclic ladder-type terbenzodithiophene (TBDT) structures merging three fused benzodithophenes was developed. Two TBDT conjugated isomers, named as syn-TBDT and anti-TBDT, where the two thienyl rings in the outmost BDT units are in the syn- and anti-fashion, are designed. Two decyl groups are introduced to their 6,13 and 7,14-positions to form four isomeric 6,13-syn-TBDT, 7,14-syn-TBDT, 6,13-anti-TBDT, and 7,14-anti-TBDT structures which are constructed by the DBU-induced 6-benzannulation involving propargyl-allenyl isomerization of the dieneyne moieties in the corresponding precursors followed by 6 pi-electro-cyclization/aromatization, while isomeric TD-syn-TBDT and TD-anti-TBDT with four decyl groups substituted at 6,7,13,14-positions are synthesized via palladium-catalyzed dialkylacetylene insertion/C-H arylation of the corresponding iodobiaryl precursors. The intrinsic properties can be modulated by molecular manipulation of the main-chain and side-chain isomeric structures. anti-TBDT derivatives exhibit higher melting points, larger bandgaps, stronger intermolecular interactions, and higher mobility than the corresponding syn-TBDT analogues. These molecules can be further utilized as building blocks to make various TBDT-based materials for optoelectronic applications.