Polyrotaxane Containing a Blocking Group in Every Structural Unit of the Polymer Chain. Direct Synthesis of Poly(alkylenebenzimidazole) Rotaxane from Ru Complex-Catalyzed Reaction of 1,12-Dodecanediol and 3,3‘-Diaminobenzidine in the Presence of Cyclodextrin
Polyrotaxane Containing a Blocking Group in Every Structural Unit of the Polymer Chain. Direct Synthesis of Poly(alkylenebenzimidazole) Rotaxane from Ru Complex-Catalyzed Reaction of 1,12-Dodecanediol and 3,3‘-Diaminobenzidine in the Presence of Cyclodextrin
复制标题
DOI：
10.1021/ja953101j
复制
发表时间：
1996-02
影响因子：
15
通讯作者：
I. Yamaguchi;K. Osakada;Takakazu Yamamoto
中科院分区：
文献类型：
--
作者：
I. Yamaguchi;K. Osakada;Takakazu Yamamoto
含有大环分子和线型聚合物分子的聚轮烷2-6由于其结构和性质，以及作为电子开关和光开关的潜在分子材料的潜在用途，引起了越来越多的关注。7-9已报道的大多数聚轮烷都含有环糊精或冠醚分子，这些分子可以附着在聚乙烯、聚氧乙烷和聚酯等聚合物上。大环分子能够沿着聚合物链移动，尽管聚合物链两端的笨重的末端封端基团阻止了大环从超分子体系中释放。双功能化合物与聚亚甲基链和大分子基团在具有合适空腔尺寸的大环存在下交替缩聚，将得到一种在主链的每个结构单元中都含有一个封闭基团的新型聚轮烷，如图1所示。该体系中的大环环固定在两个封闭基团之间。关于这类低聚紫杉烷的报道还很少。10我们合成这种新型聚轮烷的方法包括在R-环糊精(R-CD)存在的情况下制备聚(亚烷基苯并咪唑)，因为R-CD可以包括亚烷链，但空腔尺寸太小(∼4.5ra直径)，不包括苯并咪唑基。传统的聚苯并咪唑11的制备方法需要在强酸性或苛刻的热条件下分解环糊精，不适用于此目的。因此，我们考察了RuCl2(PPh_3)_3催化伯醇与1，2-二氨基苯缩合生成咪唑环12，用于R，ω-二醇与3，3‘-二氨基联胺在大环化合物存在下的缩聚反应。3，3‘-二氨基联胺与1，12-十二二醇的反应
Polyrotaxanes that contain macrocyclic molecules and a linear polymer molecule1 have attracted growing attention due to both interest in the structure and properties2-6 and the potential utility as a molecular material for electron switching and photoswitching. 7-9 Most of the polyrotaxanes already reported contain cyclodextrin or crown ether molecules that thread onto polymers such as polyethylene, poly (ethylene oxide), and polyester. The macrocyclic molecules are able to move along the polymer chain, although bulky end-capping groups at both ends of the polymer chain prevent the macrocycles from being released from the supramolecular system. Alternating polycondensation of a bifunctional compound with the polymethylene chain and with a bulky group in the presence of a macrocycle with a suitable cavity size would give a novel type of polyrotaxane containing a blocking group in every structural unit of the main chain, as shown in Chart 1. Macrocycle rings in this system are fixed between two blocking groups. There have been only a few reports on this kind of oligorotaxane. 10 Our approach to synthesizing this novel type of polyrotaxane involves preparation of poly (alkylenebenzimidazole) in the presence of R-cyclodextrin (R-CD), since R-CD could include the alkylene chain but has too small a cavity size (∼ 4.5 Å diameter) to include the benzimidazole group. Conventional preparations of poly (benzimidazole) 11 require highly acidic or severe thermal conditions, under which cyclodextrin would be decomposed, and are not suitable for this purpose. Thus, we examined the RuCl2 (PPh3) 3-catalyzed condensation of a primary alcohol with 1, 2-diaminobenzene to form an imidazole ring12 for polycondensation of the R, ω-diol with 3, 3′-diaminobenzidine in the presence of the macrocyclic compound. Reaction of 3, 3′-diaminobenzidine, 1, 12-dodecanediol, and