Tetraaza[14]- and Octaaza[18]paracyclophane: Synthesis and Characterization of Their Neutral and Cationic States
Tetraaza[14]- and Octaaza[18]paracyclophane: Synthesis and Characterization of Their Neutral and Cationic States
复制标题
四氮杂[14]-和八氮杂[18]对环芳烷：中性态和阳离子态的合成和表征
DOI：
10.1021/acs.joc.7b02437
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发表时间：
2017
影响因子：
3.6
通讯作者：
S. Seki
中科院分区：
文献类型：
--
作者：
D. Sakamaki;A. Ito;Y. Tsutsui;S. Seki
合成了两种含氮[1n]的副环环烷，四氮杂[14]副环环烷（P4）和八氮杂[18]副环环烷（P8），这是迄今为止合成的最小和最大的单分散聚苯胺大环低聚物。本文报道了这两种不同环尺寸的大环阳离子的电子性质。结合ESR光谱和DFT计算，认为p4·+属于离域III类或处于II/III类交界线上，而ep8·+属于定域II类混价体系。我们成功地分离了p4作为稳定的指示盐tp42 +·2[SbF6]−，并通过x射线晶体分析确定了p42 +的结构。对p42 +·2[SbF6]−的变温核磁共振测量明确表明p42 +是一个具有单重态基态的22π电子体系。通过x射线晶体分析发现，p86 +·6[SbCl6]−在p86 +的大环腔中含有一个SbCl6阴离子。
Two kinds of aza[1n]paracyclophanes, tetraaza[14]paracyclophane (P4) and octaaza[18]paracyclophane (P8), were synthesized as the smallest and the largest monodisperse macrocyclic oligomers of polyaniline ever made. Herein we report the electronic nature of the cationic species of these two macrocycles with different ring size. By combining ESR spectroscopy and DFT calculations it was suggested thatP4·+was classified as delocalized class III or poised on the class II/III borderline whileP8·+was regarded as a localized class II mixed-valence system. We successfully isolated the dication ofP4as a stable dicationic saltP42+·2[SbF6]−, and the structure ofP42+was determined by X-ray crystal analysis. Variable-temperature NMR measurements forP42+·2[SbF6]−unequivocally showed thatP42+was a 22π electron system with a singlet ground state. The supercharged hexacation ofP8was also isolated asP86+·6[SbCl6]−, and X-ray crystal analysis revealed thatP86+includes one SbCl6–anion in its macrocyclic cavity.