Benzo‐Extended Cyclohepta[
<i>def</i>
]fluorene Derivatives with Very Low‐Lying Triplet States
作者:Fupeng Wu、Ji Ma、Federico Lombardi、Yubin Fu、Fupin Liu、Zhijie Huang、Renxiang Liu、Hartmut Komber、Dimitris I. Alexandropoulos、Evgenia Dmitrieva、Thorsten G. Lohr、Noel Israel、Alexey A. Popov、Junzhi Liu、Lapo Bogani、Xinliang Feng
DOI:10.1002/anie.202202170
日期:2022.6.7
Three open-shell non-alternant polycyclic hydrocarbons (PHs) based on the skeleton of cyclohepta[def]fluorene are synthesized via an efficient benzannulation stabilization strategy. The obtained persistent singlet diradcialoids have a narrow optical energy gap (0.52–0.69 eV). Moreover, variable-temperature EPR measurements indicate that all of them have a low-lying triplet state with an extremely small
organoborane π-system has led to the generation of open-shell boron-doped molecular carbons (BMCs). Theoretical and experimental studies demonstrate that the two as-synthesized BMCs containing a pentagonal ring have local antiaromaticity, an internal quinoidal substructure and thus singlet diradical structures, as well as intriguing properties, such as very broad light absorption and superior photothermal