Acyclic, Linear Oligo-meta-phenylenes as Multipotent Base Materials for Highly Efficient Single-layer Organic Light-emitting Devices

Oligo-meta-phenylenes have been designed and synthesized as multipotent base materials of single-layer organic light-emitting devices. Simple molecular structures of oligo-meta-phenylenes composed of linear phenylene arrays benefited from the wealth of modern reactions available for biaryl couplings and were concisely synthesized in a series. Structure-performance relationship studies with the first seven congeners revealed key features important for the multipotent materials in single-layer devices. As a result, highly efficient phosphorescent electroluminescence was made possible in a highly simplified device architecture comprising one-region, single-layer configurations. Detailed investigations with hole-only devices disclosed that the hole mobility was effectively retarded by potent materials, which should facilitate hole/electron recombination for electroluminescence.