Solid‐State Room‐Temperature Near‐Infrared Photoluminescence of a Stable Organic Radical
Ryota Matsuoka, Shojiro Kimura, Tetsuro Kusamoto
Abstract
Abstract Luminescent organic radicals often exhibit unique emission properties when isolated in solution or dispersed in host materials. However, luminescent properties of radicals in the fully aggregated pure solid state have rarely been investigated, especially at room temperature. Herein, a luminescent stable organic radical with a 3‐pyridyl moiety, the (2,4‐dichloro‐3‐pyridyl)bis(2,4,6‐trichlorophenyl)methyl radical (metaPyBTM), was synthesized and characterized. Although the electronic structures and photophysical properties in solution of metaPyBTM and its analogues are similar, metaPyBTM displays distinct near‐infrared photoluminescence in the pure crystalline state at room temperature. The solid‐state luminescence properties of metaPyBTM depend strongly on temperature and the degree of aggregation. An external magnetic field also modulates the emission spectrum of metaPyBTM in the moderately aggregated state.