Creation of room temperature-phosphorescent organic molecules without rare metals

2014 Fiscal Year Final Research Report

• 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
• Keywords: リン光 / 有機発光材料 / 固体発光 / 室温リン光

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.

Free Research Field

有機材料化学