Nippon Steel and Sumikin Chemical Co.

Kitakyūshū, Japan

Nippon Steel and Sumikin Chemical Co.

Kitakyūshū, Japan
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Yoon J.,Keimyung University | Adachi K.,Marine Biotechnology Institute | Adachi K.,Nippon Steel and Sumikin Chemical Co. | Kasai H.,Kitasato University
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology | Year: 2014

A Gram-negative, strictly aerobic, pale-yellow pigmented, rod-shaped bacterium designated A4O-5T was isolated from a red coloured marine alga (Chondrus ocellatus Holmes). Phylogenetic analyses based on the 16S rRNA gene sequence indicated that the new strain was affiliated with the family Flavobacteriaceae and shared approximately 90 % sequence similarity with Leptobacterium flavescens YM3-0301T and Gangjinia marincola GJ16 T. The strain could be differentiated phenotypically from the related members of the family Flavobacteriaceae. The major fatty acids of strain A4O-5T were identified as iso-C15:0, iso-C17:0 3-OH and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). A complex polar lipid profile was present consisting of phosphatidylethanolamine, an unidentified phospholipid, three unidentified amino lipids and an unidentified lipid. The DNA G+C content of the strain was determined to be 41.9 mol% and the major respiratory quinone was identified as menaquinone 6 (MK-6). From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel genus in the family Flavobacteriaceae, for which the name Citreitalea marina gen. nov., sp. nov. is proposed. The type strain of C. marina is A4O-5T (=KCTC 32483T=NBRC 109918T). © 2014 Springer International Publishing.


Yoon J.,Keimyung University | Adachi K.,Marine Biotechnology Institute | Adachi K.,Nippon Steel and Sumikin Chemical Co. | Kasai H.,Kitasato University
Journal of General and Applied Microbiology | Year: 2014

A Gram-negative, strictly aerobic, reddish-pink-pigmented, non-motile, rod-shaped strain designated A6F-52T was isolated from a lake sediment sample. Preliminary analysis based on the 16S rRNA gene sequence revealed that the novel isolate could be affiliated with the family Catalimonadaceae of the phylum Bacteroidetes and that it showed highest sequence similarity (97.2%) to Catalinimonas alkaloidigena CNU-914T. The level of DNA-DNA relatedness between strains A6F-52T and Catalinimonas alkaloidigena CNU-914T was less than 70%, which is accepted as the phylogenetic definition of a species. The DNA G+C content of strain A6F-52T was 44.4 mol%; MK-7 was the major menaquinone; and the presence of iso-C15: 0, C16: 1 ω5C and iso-C17: 0 3-OH as the major cellular fatty acids supported the identification of the novel isolate as a member of the genus Catalinimonas. A complex polar lipid profile was present consisting of phosphatidylethanolamine, an unidentified phospholipid, and an unidentified lipid. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel species for which the name Catalinimonas niigatensis sp. nov. is proposed. The type strain of Catalinimonas niigatensis is A6F-52T (= KCTC 32474T = NBRC 109829T). © 2014 Applied Microbiology, Molecular and Cellular Biosciences Research Foundation.


Li B.,Kyushu University | Nomura H.,Kyushu University | Miyazaki H.,Kyushu University | Miyazaki H.,Nippon Steel and Sumikin Chemical Co. | And 6 more authors.
Chemistry Letters | Year: 2014

We demonstrate two efficient blue-green thermally activated delayed fluorescence (TADF) compounds comprising a dimeric phenylcarbazole and four cyano substituents on the phenyl rings. A comparison of the 2,6-dicyano- substituted derivative (26IPNDCz) with the 3,5-dicyano-substituted derivative (35IPNDCz) shows that 26IPNDCz provides a larger dihedral angle and a lower decrease in the energy difference between the first singlet and triplet excited states (ΔEST) and the TADF lifetime. An organic light-emitting diode based on 26IPNDCz afforded an external quantum efficiency of 10% with reduced efficiency roll-off. © 2014 The Chemical Society of Japan.


Hirata S.,Kyushu University | Sakai Y.,Kyushu University | Sakai Y.,Dyden Corporation | Masui K.,Kyushu University | And 18 more authors.
Nature Materials | Year: 2015

Organic compounds that exhibit highly efficient, stable blue emission are required to realize inexpensive organic light-emitting diodes for future displays and lighting applications. Here, we define the design rules for increasing the electroluminescence efficiency of blue-emitting organic molecules that exhibit thermally activated delayed fluorescence. We show that a large delocalization of the highest occupied molecular orbital and lowest unoccupied molecular orbital in these charge-transfer compounds enhances the rate of radiative decay considerably by inducing a large oscillator strength even when there is a small overlap between the two wavefunctions. A compound based on our design principles exhibited a high rate of fluorescence decay and efficient up-conversion of triplet excitons into singlet excited states, leading to both photoluminescence and internal electroluminescence quantum yields of nearly 100%. © 2015 Macmillan Publishers Limited. All rights reserved.


Sakai Y.,Kyushu University | Sakai Y.,Dyden Corporation | Sagara Y.,Kyushu University | Nomura H.,Kyushu University | And 6 more authors.
Chemical Communications | Year: 2015

Metal complexes emitting thermally activated delayed fluorescence based on intra-ligand charge transfer and enhanced by metallization were synthesized. Organic light-emitting diodes using a thermally stable zinc complex processed by vacuum vapor deposition achieved an external quantum efficiency of nearly 20%. This journal is © The Royal Society of Chemistry 2015.


Pandey S.S.,Kyushu Institute of Technology | Watanabe R.,Kyushu Institute of Technology | Fujikawa N.,Kyushu Institute of Technology | Shivashimpi G.M.,Kyushu Institute of Technology | And 3 more authors.
Tetrahedron | Year: 2013

Aiming toward the far-red to near infra-red (NIR) photon harvesting, three new unsymmetrical squaraine dyes bearing direct ring carboxy functionalized indole as an anchoring moiety with varying donor groups with extended π-conjugation have been successfully synthesized and utilized for dye sensitized solar cell fabrication. Under simulated solar irradiation, dye SQ-8 gave a photoconversion efficiency of 3.3% mainly harvesting photons in the far-red region between 500 and 700 nm. By extending the π-conjugation of the donor moieties in the novel unsymmetrical squaraine dyes, it was possible to extend the light absorption from far-red to NIR wavelength region. In spite of good light absorption up to 900 nm and energetic matching, dye SQ-16 was found to exhibit the decreased photon harvesting, which was explained by the enhanced dye aggregation along with its difficulty in facile electron injection as indicated from electronic absorption spectroscopic and DFT calculation results, respectively. © 2013 Elsevier Ltd. All rights reserved.


Shivashimpi G.M.,Kyushu Institute of Technology | Pandey S.S.,Kyushu Institute of Technology | Watanabe R.,Kyushu Institute of Technology | Fujikawa N.,Kyushu Institute of Technology | And 3 more authors.
Journal of Photochemistry and Photobiology A: Chemistry | Year: 2014

A series of indole based unsymmetrical squaraine dyes bearing various anchoring groups such as carboxylate (SQ-A), cyanoacrylate (SQ-B) and thiophene-bridged cyanoacrylate (SQ-C) were synthesized and evaluated for their performance in dye sensitized solar cells (DSSCs) under similar experimental conditions. Electronic absorption spectral investigation on thin films of these dyes adsorbed on nanoporous TiO2 reveals relatively enhanced spectral broadening upon the incorporation of cyanoacrylate functionality as anchoring group. Incorporation of thiophene π-bridge between the main chromophore and anchoring group (SQ-C) although resulted in to bathochromic shift in the far-red region but hampered photon harvesting due to relatively enhanced dye aggregation. Unsymmetrical squaraine dye (SQ-B) bearing cyanoacrylate anchoring group directly substituted and in conjugation with aromatic chromophore exhibited the best photovoltaic performance giving photoconversion efficiency of 5.03% under simulated solar irradiation. © 2013 Elsevier B.V. All rights reserved.


Li J.,Kyushu University | Zhang Q.,Kyushu University | Nomura H.,Kyushu University | Miyazaki H.,Kyushu University | And 2 more authors.
Applied Physics Letters | Year: 2014

Intense nπ∗ fluorescence from a nitrogen-rich heterocyclic compound, 2,5,8-tris(4-fluoro-3-methylphenyl)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3MF), is demonstrated. The overlap-forbidden nature of the nπ∗ transition and the higher energy of the 3ππ∗ state than the 3nπ∗ one lead to a small energy difference between the lowest singlet (S1) and triplet (T1) excited states of HAP-3MF. Green-emitting HAP-3MF has a moderate photoluminescence quantum yield of 0.26 in both toluene and doped film. However, an organic light-emitting diode containing HAP-3MF achieved a high external quantum efficiency of 6.0%, indicating that HAP-3MF harvests singlet excitons through a thermally activated T1 → S1 pathway in the electroluminescent process. © 2014 AIP Publishing LLC.


Li J.,Kyushu University | Nomura H.,Kyushu University | Miyazaki H.,Kyushu University | Miyazaki H.,Nippon Steel and Sumikin Chemical Co. | Adachi C.,Kyushu University
Chemical Communications | Year: 2014

Highly efficient exciplex systems incorporating a heptazine derivative (HAP-3MF) as an electron acceptor and 1,3-di(9H-carbazol-9-yl)benzene (mCP) as an electron donor are developed. An organic light-emitting diode containing 8 wt% HAP-3MF:mCP as an emitting layer exhibits a maximum external quantum efficiency of 11.3%. This journal is © the Partner Organisations 2014.


Li J.,Kyushu University | Nakagawa T.,Kyushu University | Macdonald J.,Kyushu University | Macdonald J.,CSIRO | And 5 more authors.
Advanced Materials | Year: 2013

An orange-red organic light-emitting diode containing a heptazine derivative exhibits high performance with a maximum external quantum efficiency of 17.5 ± 1.3% and a peak luminance of 17000 ± 1600 cd m -2 without any light out-coupling enhancement. The high electroluminescence performance can be ascribed to the presence of an efficient up-conversion channel from the lowest triplet state to the lowest singlet state. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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