This paper reports the synthesis of an alternating copolymer consisting of dithienosilole (DTS) and thienopyrroledione (TPD) units via palladium-catalyzed direct arylation polymerization (DArP). Although DArP has recently attracted much attention as an easy synthetic method of π-conjugated polymers without the need for prepreparation of organometallic monomers, there are two major problems that must be eliminated. One is homocoupling producing structural defects in the polymer chain, and the other is byproduction of insoluble materials. In this study, we have found that the combined use of P­(2-MeOC6H4)3 and P­(2-Me2NC6H4)3 ligands effectively prevents these side reactions, resulting in poly­(DTS-alt-TPD) (M n GPC = 15000, M w/M n = 2.57) with good solubility in high yield (84%).

This paper reports a novel mixed ligand catalyst for palladium-catalyzed direct arylation polymerization (DArP) of 2,6-diiodo­dithienosilole (DTS-I2) and thieno­pyrroledione (TPD-H2) to give poly­(DTS-alt-TPD). It has been documented that this monomer combination has a marked tendency to form homocoupling and branching defects in polymer chains, and the latter defects eventually lead to the formation of insoluble materials. This paper demonstrates that the combined use of P­(o-MeOC6H4)3 and TMEDA ligands effectively prevents the defect formation. The side reactions that afford structural defects constitute a sequential process triggered by the reduction of DTS-I units. TMEDA as a simple diamine effectively inhibits the reduction of DTS-I units, giving poly­(DTS-alt-TPD) (M n GPC = 20 000) in high cross-coupling selectivity (99%).

A new display with quantum dot color filter (QD-CF) is attracting attention as a nextgeneration display. The QD-CF display can achieve high brightness, definition and contrast. It is essential for QD-CF structure to form "banks" separating QD materials.In this paper, we introduce the novel photo-sensitive light-shielding banks with high reflectivity, which are suitable for QD-CF display. This bank material contains both TiO 2 pigment and UV transparent black pigment. The material can form gray banks which have a thickness of 10 μm with a good taper angle of 86°. The banks show good light-shielding property (transparency@450 nm<1%), high reflectivity of 50.8% at 550 nm, and high heat resistance (1% weight loss temperature is 353 o C). This developed material is ideal for application of QD-CF display.