Zhang Q.,Kyushu University |
Kuwabara H.,Kyushu University |
Kuwabara H.,Nippon Kayaku Co. |
Potscavage W.J.,Kyushu University |
And 5 more authors.
Journal of the American Chemical Society | Year: 2014
Red fluorescent molecules suffer from large, non-radiative internal conversion rates (kIC) governed by the energy gap law. To design efficient red thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs), a large fluorescence rate (kF) as well as a small energy difference between the lowest singlet and triplet excited states (ΔEST) is necessary. Herein, we demonstrated that increasing the distance between donor (D) and acceptor (A) in intramolecular-charge-transfer molecules is a promising strategy for simultaneously achieving small ΔEST and large kF. Four D-Ph-A-Ph-D-type molecules with an anthraquinone acceptor, phenyl (Ph) bridge, and various donors were designed, synthesized, and compared with corresponding D-A-D-type molecules. Yellow to red TADF was observed from all of them. The kF and ΔEST values determined from the measurements of quantum yield and lifetime of the fluorescence and TADF components are in good agreement with those predicted by corrected time-dependent density functional theory and are approximatively proportional to the square of the cosine of the theoretical twisting angles between each subunit. However, the introduction of a Ph-bridge was found to enhance kF without increasing ΔEST. Molecular simulation revealed a twisting and stretching motion of the N-C bond in the D-A-type molecules, which is thought to lower ΔEST and kF but raise kIC, that was experimentally confirmed in both solution and doped film. OLEDs containing D-Ph-A-Ph-D-type molecules with diphenylamine and bis(4-biphenyl)amine donors demonstrated maximum external quantum efficiencies of 12.5% and 9.0% with emission peaks at 624 and 637 nm, respectively. © 2014 American Chemical Society. Source
Niwa M.,Nippon Kayaku Co.
Bioanalysis | Year: 2012
Chemical derivatization is the only technique that directly affects the physicochemical property of an analyte in an LC-MS/MS assay platform. On the other side, current MS instruments are extremely sensitive, but still their absolute sensitivity is analyte-dependent. In this review, first, difficulty in analyzing neutral compounds and introducing acidity/basicity and/or proton affinity will be described. Second, the sweet spot of the conventional MS ion source across clogP values is presented. Third, optimization of hydrophilicity/hydrophobicity by derivatization is described. Lastly, development of a new derivatizing reagent specifically designed for LC-MS/MS is described and its significance in pharmacokinetic analysis is discussed. © 2012 Future Science Ltd. Source
Meiji Seika Pharma Co. and Nippon Kayaku Co. | Date: 2014-01-29
The present invention provides an aqueous suspended agricultural chemical composition comprising an agricultural chemical active ingredient, an alkyl naphthalene sulfonate formalin condensate and one or two or more compounds selected from the group consisting of an alkyl sulfate, a polyoxyalkylene alkyl ether sulfate, an alkyl phosphoric acid and a salt thereof, a polyoxyalkylene alkyl ether phosphoric acid and a salt thereof, and a polyoxyalkylene alkyl ether acetic acid and a salt thereof. The aqueous suspended agricultural chemical composition suppresses the crystal growth of the agricultural chemical active ingredient, and has an excellent effect on pest control and an excellent storage stability.
Meiji Seika Pharma Co. and Nippon Kayaku Co. | Date: 2011-11-16
An objective of the present invention is to provide a process for producing 4-carbonyl oxyquinoline derivatives useful as agricultural and horticultural pesticides and fungicides. The objective can be attained by a process for producing 4-carbonyl oxyquinoline derivatives represented by general formula (1), the process including reacting a quinolone derivative with a halogenated compound or an acid anhydride in the presence of a phase transfer catalyst and a base.
Nippon Kayaku Co., Basf and Central Glass Co. | Date: 2014-05-23
The present invention has the objective of providing an infrared reflective film by means of which it is possible to achieve an effective heat-shielding performance with a smaller number of layers than hitherto using a construction employing specified infrared reflective layers. Solution Means The infrared reflective film of the present invention has at least two infrared reflective layers and, of these infrared reflective layers, the center reflective wavelength of at least one infrared reflective layer is between 1200 and 1300 nm. Furthermore, the laminated glass of the present invention is formed by interposing this infrared reflective film between two sheets of intermediate film, and laminating these between two sheets of glass.