Shi Xueliang, Gopalakrishna Tullimilli Y, Wang Qing, Chi Chunyan
Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore.
Chemistry. 2017 Jun 22;23(35):8525-8531. doi: 10.1002/chem.201701813. Epub 2017 May 30.
A series of non-classical S-heteroacenes were synthesized and exhibited intriguing physical properties and chemical reactivities that are very different from classical acenes. X-ray crystallographic analyses revealed that all acenothiophene derivatives Ph-AT-1-Ph-AT-3 had an o-quinoidal π-conjugation with large bond-length alternation, whereas the acenodithiophene derivative Ph-ADT-3 easily dimerized or reacted with oxygen to form a peroxy-bridged dimer. The long acenothiophene Ph-AT-4 was also highly reactive. The origin of these unique properties was investigated carefully by both experiments and theoretical calculations. The high reactivity of the long non-classical S-heteroacenes can be explained by their intrinsic open-shell diradical character as well as the o-quinoidal conjugation.
合成了一系列非经典的 S-杂并苯，它们展现出与经典并苯非常不同的有趣物理性质和化学反应活性。X 射线晶体学分析表明，所有苊并噻吩衍生物 Ph-AT-1-Ph-AT-3 都具有邻醌型 π-共轭，键长交替较大，而苊并二噻吩衍生物 Ph-ADT-3 很容易二聚或与氧反应形成过氧桥连二聚体。长链苊并噻吩 Ph-AT-4 也具有高反应活性。通过实验和理论计算仔细研究了这些独特性质的起源。长链非经典 S-杂并苯的高反应活性可以用其固有的开壳双自由基特性以及邻醌型共轭来解释。
