Synthesis of novel rigid-rod polypropellanes

[3.3.1][3.3.1]正庚烷衍生物1，3-脱氢金刚烷(1)、5-丁基-1，3-脱氢金刚烷(2)和6-丁基-6-甲基-1，3-脱氢金刚烷(3)在0℃的CH2Cl2中进行阳离子开环聚合反应6~42h，1-3中的中心a键被完全打开，得到新的聚(3.3.1]金刚烷)S，聚(1，3-金刚烷)S，产率较高。得到的具有柔性丁基取代基的聚(2)和聚(3)可溶于氯仿、四氢呋喃和1，2-二氯苯，聚合度大于30，而聚(1)难溶于常见有机溶剂。所有脂肪族聚(1，3-金刚烷)S均表现出较高的热稳定性，其10%失重温度均在430℃以上。1，3-脱氢金刚烷与丙烯腈或丙烯酸甲酯发生自发共聚反应，得到电子密度较高的交替共聚物。

Cationic ring-opening polymerizations of [3.3.1] propellane derivatives, 1, 3-dehydroadamantane (1), 5-butyl-1, 3-dehydroadamantane (2), and 6-butyl-6-methyl-1, 3-dehydroadamantane (3) were carried out with CF_3SO_3H in CH_2 Cl_2 at 0℃ for 6-42 h. The central a-bonds in 1-3 were exclusively opened to afford novel poly ([3.3.1]propellane)s, poly(1, 3-adamantane)s, in good to quantitative yields. The resulting poly (2) and poly (3) possessing flexible butyl substituents were soluble in chloroform, THF, and 1, 2-dichlorobenzene, and the degree of polymerization was estimated to be greater than 30, while the poly (1) was hardly soluble in the common organic solvents. All aliphatic poly (1, 3-adamantane) s showed high thermal stability, whose 10% weight loss temperatures were over 430℃. 1, 3-Dehydroadamantanes underwent the spontaneous copolymerization with acrylonitrile or methyl acrylate to afford the alternating copolymer, indicating the high electron-density.