We have significantly improved the emission efficiency in an organic light-emitting device (OLED) based on iridium (III)bis[(4,6-di-fluoropheny)-pyridinato-N,C2′]picolinate (FIrpic). To improve the efficiency, 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl, which has a high triplet energy, was used as the carrier-transporting host for the emissive layer. The FIrpic-based OLED exhibited a maximum external quantum efficiency of 10.4%, corresponding to a current efficiency of 20.4 cd/A, and a maximum power efficiency of 10.5 lm/W. The efficiency was drastically improved compared to that of a previously reported FIrpic-based OLED. This result indicates that triplet energy is efficiently confined on FIrpic molecules, resulting in the high efficiency.

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In all living systems, the genome is replicated by proteins that are encoded within the genome itself. This universal reaction is essential to allow the system to evolve. Here, we have constructed a simplified system involving encapsulated macromolecules termed a "self-encoding system", in which the genetic information is replicated by self-encoded replicase in liposomes. That is, the universal reaction was reconstituted within a microcompartment bound by a lipid bilayer. The system was assembled by using one template RNA sequence as the information molecule and an in vitro translation system reconstituted from purified translation factors as the machinery for decoding the information. In this system, the catalytic subunit of Qbeta replicase is synthesized from the template RNA that encodes the protein. The replicase then replicates the template RNA that was used for its production. This in-liposome self-encoding system is one of the simplest such systems available; it consists of only 144 gene products, while the information and the function for its replication are encoded on different molecules and are compartmentalized into the microenvironment for evolvability.

From a one-pot nickel-mediated Yamamoto-type coupling reaction of m-dibromobenzene, five congeners of [n]cyclo-meta-phenylenes were synthesized and fully characterized. The [n]cyclo-meta-phenylenes possessed a commonly shared arylene unit and intermolecular contacts but varied in packing structures in the crystalline solid state. Columnar assembly of larger congeners yielded nanoporous crystals with carbonaceous walls to capture minor protic or aliphatic solvent molecules. The concise and scalable synthesis allowed exploration of the macrocyclic hydrocarbons as bipolar charge carrier transport materials in organic light-emitting diode devices.

New luminescent compounds consisting of 10H-phenoxaboryl group as an electron-accepting unit and carbazole (9), 9,9dimethylacridane (10), or phenoxazine (11) as an electron-donating unit have been synthesized. Compounds 10 and 11 showed thermally activated delayed fluorescence (TADF) with light blue and green emissions, respectively, with very high PL quantum yields (PLQYs), however, compound 9 exhibited only a prompt emission and no delayed component. Photoluminescence studies and quantum chemical calculation based on density functional theory (DFT) and timedependent density functional theory (TD-DFT) revealed that in comparison with compound 9, HOMO and LUMO for compounds 10 and 11 are well separated, resulting in lowering ∆EST and effective reverse intersystem crossing (RISC) between a lowest triplet excited state (T1) and a lowest singlet excited state (S1). Organic light-emitting diodes (OLEDs) using compounds 10 and 11 exhibited light blue and green emissions with very good maximum ηext of 15.1% and 22.1%, respectively.