Novel arylboranes for use in electronic and optoelectronic devices, e.g. OLEDs
Scientists from Goethe University of Frankfurt am Main synthesized novel arylborane compounds with extraordinary electronic, chemical, and optical properties. The novel blue fluorescent dyes are well suited for use in organic light emitting diodes (OLEDs).
Blue fluorescent dyes constitute a core component in OLEDs. So far, polycyclic aromatic hydrocarbons are mainly used for this purpose. Only, these compounds often contain nitrogen or sulfur atoms and are therefore electron-rich. Alternative fluorophores with molecular orbitals of lower energy are difficult to find. By incorporation of boron atoms it is possible to obtain electron-deficient compounds. Still up to present, practical use of such boron substances has been limited by their sensibility to water.
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The novel arylborane compounds show an intense blue fluorescence with an emission maximum around 450 nm. A high fluorescence quantum yield can be reached in solution (up to 90 %) and in solid state (approx. 50 %). The compounds are resistant to environmental influences, e.g. oxygen and moisture, and towards electrochemical reduction. In addition, the novel arylboranes are readily soluble in organic solvents and sublimable. Synthesis of these compounds involves six to eight steps starting with low-priced chemicals. By variation of the starting reagents the structure of the final arylborane can be modified and the properties can be optimized with regard to the field of application. For instance, it is possible to synthesize bromine-substituted derivates which can be further processed in cross-coupling reactions.
- The novel compounds show an intense blue fluorescence with high quantum yield in solution and in solid state.
- Reversible redox behavior designates the compounds for use as electron conductors with a long lifetime.
- The novel arylboranes are resistant to air and moisture (in contrast to most borane compounds).
- The chemical synthesis of the inventive compounds is accomplished with inexpensive chemicals and in good yield.
Scope of application
The innovative compounds can be used as blue fluorescent emitter. They are able to influence the electron conductivity of electronic materials, e.g. OLEDs. Furthermore, the novel compounds might be used in photo-sensitive materials, as for instance organic solar cells. Here, they could serve as electron absorber to improve charge separation.
Licensing or assignment of the technology is possible as well as a cooperation for further development of the invention.
- DE 10 2014 004 224.3 pending
- PCT /DE2015/100118 pending
- WO 2015/144133 A1 pending