Enhancing stability of diradical polycyclic hydrocarbons via P=O-attaching  

作　　者：Jingyuan Yang Xinyu Tian Liuzhong Yuan Yu Liu Yue Wang Chuandong Dou 

机构地区：[1]State Key Laboratory of Supramolecular Structure and Materials,College of Chemistry,Jilin University,Changchun 130012,China [2]Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials,Soochow University,Suzhou 215123,China

出　　处：《Chinese Chemical Letters》2024年第8期309-313,共5页中国化学快报（英文版）

基　　金：supported by Jilin Scientific and Technological Development Program(Nos.20220101054JC,20220201085GX);National Natural Science Foundation of China(Nos.22175074,52373182).

摘　　要：Diradical polycyclic hydrocarbons(PHs)have unique open-shell structures and interesting physical prop-erties.However,owing to high reactivity of unpaired electrons,such open-shell organic diradicaloids are usually less stable than closed-shell systems,limiting their practical applications.In this study,we report P=O-attaching of diradical PHs as a new strategy to enhance their stability while maintaining diradi-cal properties.Three P=O-attached PHs containing the indeno[1,2-b]fluorene,fluoreno[3,2-b]fluorene and indeno[2,1-b]fluoreneπ-skeletons,respectively,were designed and synthesized.As theoretically and ex-perimentally proved,two of them have the relatively large diradical characters and open-shell singlet diradical nature.In comparison to their all-carbon analogues,the attached electron-withdrawing P=O groups endow them with much lower LUMO/HOMO energy levels but preserved magnetic activities and physical properties,such as thermally accessible triplet species and multi-redox ability.Moreover,the P=O groups effectively decrease their oxidation activities and thereby lead to their remarkably excellent ambient stabilities.Thus,this P=O-attaching strategy will be applicable to other diradical PH systems and may promote the generation of stable organic diradicaloids for radical chemistry and materials.

关 键 词：Polycyclic hydrocarbons Open-shell structure Diradical character STABILITY Oxidation activity 

分 类 号：O621[理学—有机化学]