摘要
It is highly urgent to develop synthetic strategies to make new category of stable luminescent radicals with desired emission wavelength.In this study,we have isolated two dioxoborocyclic radicals(3 and 4)by a direct synthetic route.They were characterized by UV,EPR spectroscopy and SQUID measurements.Their structures were obtained by single-crystal X-ray diffraction.Both radicals produce blue-photoluminescence(458 nm for 3 and 478 nm for 4)by radiative decay from higher excited states(D_(2)/D_(3))to the ground state(D_(0))based on theoretical calculation,breaking Kasha rule.The work records a new kind of radical emitters and the first stable radicals with blue emission bands.
基金
the National Key R&D Program of China(Grants Nos.2016YFA0300404 and 2018YFA0306004,X.W.)
the National Natural Science Foundation of China(Grants No.21525102 and 21690062 X.W.,Grants No.22033007 J.J.)for financial support.The calculations were performed at the High-Performance Computing Center of Nanjing University and the Supercomputing Center of University of Science and Technology of China.