摘要
合成了Ｚｎ、Ｐｂ两个系列卟啉金属配合物１２个，其中６个为未见文献报道的新化合物，用元素分析、ＩＲ、ＵＶ、＾１ＨＮＭＲ、ＭＳ 确证了其结构。总结了Ｚｎ、Ｐｂ与卟啉类配体配合的ＩＲ、ＵＶ、＾１ＨＮＭＲ判据。研究了这两个系列化合物的液晶性能，发现９个化合物具有液晶性。
Meso - tetrakis (4 - alkoxyphenyl) porphyrins synthesized by condensation of 4 - alkoxybenzaldehydes with pyrrole, reacted with metal acetates to form corresponding complexes. Twelve complexes of porphyrins with Zn2 + or Pb2 + have been obtained by this approach. Among them there are six new compounds. Zinc series complexes are purple crystals, formed in 80% - 90% yieid. Lead complexes are green crystals with yields ranging from 52% to 58% .
The solubility differences of target porphyrins and impurities in petroleum ether (naphtha) were exploited to improve the separation process and enhance recovery efficiency. Satisfactory purity of the porphyrins as achieved by one recrystal-ization. Compared with those of previous method, porphyrin complexes of approximately equal yields were obtained within shorter time and without need for inert atmosphere protection.
Molecular structures of all synthesized compounds were confirmed by IR, UV, :H NMR, MS and elemental analysis . Characteristic spectrometric data of IR, UV, 1H NMR related to their structures have been systematically analyzed. The N - H 3385 cm-1 IR peak of porphyrins disappears when porphyrins combine with Zn2+ or Pb2+ ion. Compared with those in UV spectrum of porphyrin, the peaks of the complex shift to lower wave numbers.1 H NMR spectrums of porphyrins complexes do not show the peak at = - 2.75 as the porphyrin precursors.
Differential scanning calorimetry (DSC) and polarizing microscope were used to probe the liquid crystal properties of the two series complexes. Nine of the two series complexes were found to exhibit liquid crystal properties. Only one synthesized substituted porphyrin which has as alkoxy chain with 16 carbon atoms shows liquid crystal properties. However, Zn2+ , Pb2+ complexes of substituted porphyrins which have alkoxy chain with 10, 12, 14, 16 or 18 carbon atoms possess liquid crystal properties and wide temperature range of liquid crystal phase transition.
出处
《有机化学》
SCIE
CAS
CSCD
北大核心
2000年第3期424-429,共6页
Chinese Journal of Organic Chemistry
基金
湖南省教委资助课题
关键词
卟啉金属配合物
合成
波谱解析
液晶性
锌
铅
metallic complex of porphyrin, synthesis, spectral analysis, liquid crystal properties
