首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Polycarboxyhydrazides with ferrocenylene groups in the main chain
Authors:Eberhard W Neuse  Harold Rosenberg
Abstract:Polycarboxyhydrazides essentially of the type \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} {\rm C}_{10} {\rm H}_8 {\rm Fe}\hbox{---}{\rm CONHNHCO}\rlap{--}]_n $\end{document}equation image are synthesized by low-temperature solution condensation of 1,1′-di(chlorocarbonyl) ferrocene with hydrazine or 1, 1′-ferrocenedicarboxyhydrazide and hexamethylphosphoramide as solvent. In an analogous manner the polycondensation of 1, 1′-di(chlorocarbonyl)ferrocene with oxalyldihydrazide leads to polyhydrazides essentially possessing the structure \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} {\rm C}_{10} {\rm H}_8 {\rm Fe}\hbox{---}{\rm CONHNHCO}\hbox{---}{\rm CONHNHCO}\rlap{--}]_n $\end{document}equation image. Both polymer types exhibit inherent viscosities (0.08–0.19 dl./g.) considerably lower than reported for analogous aliphatic or benzene-aromatic polyhydrazides. This behavior points to premature chain termination via heterobridging imide groups as a result of the welldocumented tendency of appropriately substituted ferrocene compounds to undergo intramolecular cyclization. In addition, elemental analytical and spectroscopic evidence, coupled with the failure of both polymer types to undergo cyclodehydration to the corresponding 1,3,4-oxadiazole polymers upon heat treatment, suggests some structural irregularities in the aliphatic connecting segments arising from ferrocenoylation of secondary amino groups with resultant branching. With the polyhydrazide prepared from 1, 1′-di(chlorocarbonyl)ferrocene and 1, 1′-ferrocenedicarboxyhydrazide it is shown spectroscopically that treatment with alkali results in conversation of the nonconjugated hydrazide structure of the connecting segments into the polyconjugated tautomeric enol form comprising azine groups.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号