Creation of room temperature-phosphorescent organic molecules without rare metals

Research Project

Project/Area Number	24655122
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Functional materials chemistry
Research Institution	Kyoto Institute of Technology
Principal Investigator	SHIMIZU Masaki 京都工芸繊維大学, 工芸科学研究科, 教授 (10272709)
Project Period (FY)	2012-04-01 – 2015-03-31
Project Status	Completed (Fiscal Year 2014)
Budget Amount *help	¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000) Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2013: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	リン光 / 有機発光材料 / 固体発光 / 室温リン光 / 発光材料
Outline of Final Research Achievements	We designed 1,4-bis(aroyl)-2,5-dihalobenzenes as chromophores that exhibited room temperature phosphorescence without rare metals such as iridium and platinum. The designed compounds were prepared from 2,5-dibromo-para-xylene via 4 steps. Some of the bromo derivatives in crystals were found to emit phosphorescence at room temperature. The emission color ranged from blue to green simply by changing the para-substituent on the terminal benzene rings or using thiophene as the terminal aromatic rings. The lifetime of each emission ranged in the order of micro to mili-seconds, which implied that the emission was phosphorescence. Meanwhile, no emission was observed at room temperature with both iodo and bromo derivatives when the samples were dissolved in solution, dispersed in polymer thin films, and in powder. In summary, we disclosed that 1,4-bis(aroyl)-2,5-dibromobenzenes showed crystal-induced room temperature phosphorescence.