Structural study of the aging and thermal evolution of polyiodide chains in doped trans-polyacetylene
Structural study of the aging and thermal evolution of polyiodide chains in doped trans-polyacetylene
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掺杂反式聚乙炔中聚碘链的老化和热演化的结构研究
DOI：
10.1002/macp.1992.021930404
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发表时间：
1992
影响因子：
2.5
通讯作者：
G. Wegner
中科院分区：
文献类型：
--
作者：
P. Albouy;J. Pouget;J. Halim;V. Enkelmann;G. Wegner
研究了碘掺杂聚乙炔中碘链结构随温度的变化规律。结果表明，这些链表现出第二类无序性，其特征是在链的方向上缺乏长程有序。低温下链内秩序的改善表明，这种无序的很大一部分是热性质的。在结晶碘链有机电荷转移盐中经常观察到类似的效应。此外，标称成分为chi0,24的新鲜样品在x射线束下不稳定。它们表现出一个缓慢的过渡到一个明显稳定的形式对应于CHI0,19。这种形式在链方向上的衍射图案可以用一个简单的模型定量地解释，只使用三碘化物链。并与文献中提出的其他模型进行了比较。
The evolution of the structure of iodine chains in iodine-doped polyacetylene has been followed as a function of temperature. It is shown that these chains exhibit a disorder of the second kind characterized by the lack of long-range order in chain direction. A low-temperature improvement of intra-chain order demonstrates that a substantial part of this disorder is thermal in nature. A parallel is drawn to similar effects frequently observed in crystalline iodine chain organic charge transfer salts. Furthermore, fresh samples with a nominal composition CHI0,24 are unstable under the X-ray beam. They exhibit a slow transition toward an apparently stable form corresponding to CHI0,19. The diffraction pattern in chain direction of this form can be quantitatively explained with a simple model using triiodide chains only. A comparison with other models proposed in the literature is made.