Poly(1,1-bis(dialkylamino)propan-1,3-diyl)s; conformationally-controlled oligomers bearing electroactive groups
作者:Roger W. Alder、Niall P. Hyland、John C. Jeffery、Thomas Riis-Johannessen、D. Jason Riley
DOI:10.1039/b901060b
日期:——
The design of polymers with repeating [C(NR2)2CH2CH2] units which may simultaneously provide conformational control and contain repeating electroactive centres is discussed; (NR2)2groups would be ideally provided by ortho-phenylenediamine derivatives, with 1,8-diaminonaphthalenes as alternatives. Oligomers containing 1,8-bis(methylamino)naphthalenes, up to the hexamer, were obtained by condensation of oligomers of CH3[COCH2CH2]nCOCH3 with 1,8-bis(methylamino)naphthalene, but attempts to prepare related oligomers from 1,2-bis(alkylamino)benzenes were unsuccessful, as only terminal ketone groups could be converted to aminals. Evidence for a strong preference for all-anti conformations of the main chain in the naphthalenediamine oligomers is provided by ring current effects on 1H NMR shifts, and by X-ray structures, which also provide evidence of intercalation in the solid state. Electrochemical studies of these oligomers show irreversible oxidation of oligomers in solution, but oxidation of longer oligomers leads to the deposition of a reddish-pink insoluble material which shows two reversible oxidation waves. Possible interpretation of these results is discussed.
讨论了设计含有重复[C(NR2)2CH2CH2]单元的聚合物的设计,这些单元可以同时提供构象控制和含有重复的电活性中心;(NR2)2基团将理想地由邻苯二胺衍生物提供,以1,8-二氨基萘作为替代品。通过CH3[COCH2CH2]nCOCH3与1,8-双(甲基氨基)萘的缩聚反应,得到了含有1,8-双(甲基氨基)萘的低聚物,最多达到六聚体,但试图从1,2-双(烷基氨基)苯制备相关低聚物的尝试未能成功,因为只有末端酮基团可以转化为缩二氨酸。通过环流对1H NMR位移的影响以及X射线结构,提供了对萘二胺低聚物主链中所有反式构象有强烈倾向的证据,这些结构还提供了在固态下的插层证据。对这些低聚物的电化学研究表明,溶液中的低聚物氧化是不可逆的,但对较长低聚物的氧化会导致沉积出呈现两个可逆氧化波的红色不溶物质。对这些结果的可能解释进行了讨论。