Supramolecular Gel Phase Controlled [4 + 2] Diels–Alder Photocycloaddition for Electroplex Mediated White Electroluminescence

Abstract

Diels-Alder photocycloaddition of 9-phenylethynylanthracene results in multiple [4+2] and [4+4] cycloaddition products in solution, which can be controlled to form specific products under restricted environment. We have exploited the gel phase of a 9-phenylethynylanthracence derivative as a confined medium to specifically yield the [4+2] cycloadduct in <90% yield. The photocycloadduct, which was identified as the anti-isomer exhibited a blue emission with CIE chromaticity of x = 0.16/y = 0.16. However, the chromaticity could be modulated by constructing an organic light emitting device with the photocycloadduct, using a carbazole-based hole transporting host, which resulted in white light emission with CIE chromaticity of x = 0.33/y = 0.32. This observation not only highlights the use of molecular assembly and gel chemistry to achieve the otherwise difficult to obtain photoproducts but also underlines their potential use in optoelectronic device fabrication.