Luminescence Color Tuning from Blue to Near Infrared of Stable Luminescent Solid Materials Based on Bis‐o‐Carborane‐Substituted Oligoacenes

Abstract Aryl‐substituted o ‐carboranes have shown highly efficient solid‐state emission in previous studies. To demonstrate color tuning of the solid‐state emission in an aryl‐ o ‐carborane‐based system, bis‐ o ‐carborane‐substituted oligoacenes were synthesized and their properties were systematically investigated. Optical and electrochemical measurements revealed efficient decreases in energy band gaps and lowest unoccupied molecular orbital (LUMO) levels by adding a number of fused benzene rings for the extension of π‐conjugation. As a consequence, bright solid‐state emission was observed in the region from blue to near infrared (NIR). Furthermore, various useful features were obtained from the modified o ‐carboranes as an optical material. The naphthalene derivatives exhibited aggregation‐induced emission (AIE) and almost 100 % quantum efficiency in the crystalline state. Furthermore, it was shown that the tetracene derivative with NIR‐emissive properties had high durability toward photo‐bleaching under UV irradiation.