The Synthesis and Properties of Spirophenanthrene.

Motivated by the success of 9,9'-spirobifluorene () in optoelectronic materials, we synthesized a novel spiro compound, spirophenanthrene (). Incorporating a phenanthrene unit as the core, we aimed to leverage the π-conjugation of to surpass the limitations of . Experimental and theoretical studies revealed significant advantages over , including red-shifted wavelengths, tunable LUMO energy levels, and enhanced thermal stability. These advantages suggest the potential of as versatile building blocks for diverse optoelectronic devices.