Syntheses and Physical Properties of Several Polyphenylenes Containing Mixed Linkages
作者:Yasuhiro Fujioka
DOI:10.1246/bcsj.57.3494
日期:1984.12
Fourteen macrocyclic polyphenylenes, including the following ten new compounds, were synthesized by intra- or intermolecular homo-coupling of di-Grignard compound and by cross-coupling of two kinds of di-Grignard compounds with copper(II) chloride: m,m,o,p,o-pentaphenylene; o,o,p,o,o,p-, m,o,p,m,o,p-, o,p,o,p,o,p-, m,o,p,o,p,o-, m,o,m,o,m,o-, and m,m,m,o,m,o-hexaphenylene; m,o,p,p,o,m,p-, and m,m,m,m,p,o,p-heptaphenylene; and m,o,o,m,o,o,m,o,o,m,o,o-dodecaphenylene. 1H NMR spectra of the polyphenylenes, compared with those of open-chain analogues, provide valuable information on the nonplanar spacial relationship of constituting phenylene rings. UV spectra of the compounds containing p-phenylene ring(s) suggest that the lack or decrease in intensity of K-band above ca. 260 nm or a marked shift of that band provides useful conformational information. Empirical Hückel molecular orbital calculations of longest-wavelength absorption bands of twelve polyphenylenes were also carried out. The calculations furnish additional bases for their conformational aspects deduced from their spectral data and Dreiding stereomodels. IR spectra indicate that lack of intense band(s) near 700 cm−1 may generally be regarded as a piece of plausible evidence for the macrocyclic structure containing no m-phenylene ring. Stabilities of the polyphenylenes to electron bombardment are also discussed.
合成了十四种宏环聚苯烯,包括以下十种新化合物,这些化合物是通过二格里尼亚试剂的分子内或分子间同聚合以及两种二格里尼亚试剂与氯化铜(II)交叉偶联反应合成的:m,m,o,p,o-五苯烯;o,o,p,o,o,p-、m,o,p,m,o,p-、o,p,o,p,o,p-、m,o,p,o,p,o-、m,o,m,o,m,o-、和m,m,m,o,m,o-六苯烯;m,o,p,p,o,m,p-和m,m,m,m,p,o,p-七苯烯;以及m,o,o,m,o,o,m,o,o,m,o,o-十二苯烯。聚苯烯的1H NMR光谱与其开链类似物相比,提供了构成苯环的非平面空间关系的有价值信息。含有p-苯环的化合物的紫外光谱表明,在约260 nm以上K带缺失或强度下降,或该带明显偏移,提供了有用的构象信息。对十二种聚苯烯的最长期波长吸收带进行了经验Hückel分子轨道计算。这些计算为根据光谱数据和Dreiding立体模型推导的构象方面提供了额外的依据。红外光谱表明,在700 cm−1附近缺乏强带一般可以视为缺乏m-苯环的宏环结构的一个合理证据。同时还讨论了聚苯烯在电子轰击下的稳定性。