Synthesis, Characterization, and Properties of [4]Cyclo-2,7-pyrenylene: Effects of Cyclic Structure on the Electronic Properties of Pyrene Oligomers
Synthesis, Characterization, and Properties of [4]Cyclo-2,7-pyrenylene: Effects of Cyclic Structure on the Electronic Properties of Pyrene Oligomers
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DOI：
10.1002/anie.201403624
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发表时间：
2014-06-01
影响因子：
16.6
通讯作者：
Yamago, Shigeru
中科院分区：
文献类型：
--
作者：
Iwamoto, Takahiro;Kayahara, Eiichi;Yamago, Shigeru
以芘为原料，通过铂介导的芘单元组装和铂的还原消除，经6步合成了芘的环四聚体[4]环-2,7-芘（[4]CPY），总产率为18%。两个关键中间体的结构通过x射线晶体学分析得到了明确的确定。DFT计算表明，[4]CPY的前沿轨道拓扑结构与[8]环对苯（[8]CPP）的前沿轨道拓扑结构基本相同，并且所有的芘单元都是完全共轭的。电化学分析证明[4]CPY的电子性能与[8]CPP相似。结果与得到的相应的线性芘低聚物形成鲜明对比，其中每个芘单元都是电子分离的。结果清楚地显示了环结构对环偶联分子的新作用。
A cyclic tetramer of pyrene, [4]cyclo-2,7-pyrenylene ([4]CPY), was synthesized from pyrene in six steps and 18% overall yield by the platinum-mediated assembly of pyrene units and subsequent reductive elimination of platinum. The structures of the two key intermediates were unambiguously determined by X-ray crystallographic analysis. DFT calculations showed that the topology of the frontier orbitals in [4]CPY was essentially the same as those in [8]cycloparaphenylene ([8]CPP), and that all the pyrene units were fully conjugated. The electrochemical analyses proved the electronic properties of [4]CPY to be similar to those of [8]CPP. The results are in sharp contrast to those obtained for the corresponding linear oligomers of pyrene in which each pyrene unit was electronically isolated. The results clearly show a novel effect of the cyclic structure on cyclic pi-conjugated molecules.