Die Strukturen der mittleren Ringverbindungen III. Die Struktur des Cyclododecans
Die Strukturen der mittleren Ringverbindungen III. Die Struktur des Cyclododecans
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Die Strukturen der mittleren Ringverbindungen III。
DOI：
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发表时间：
1960
期刊：
影响因子：
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通讯作者：
H. M. M. Shearer
中科院分区：
文献类型：
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作者：
J. D. Dunitz;H. M. M. Shearer
环十二烷在单斜晶系中室温结晶，晶系a = 13.27 a, b = 8.28 a, c = 5.44 a, β = 99°32′（Z = 2），空间群C2/m。晶体结构由三维PATTERSON函数确定，并通过三维差分合成重新发现。由于较大的温度因子和在y = 0和y = 1 / 2处存在的统计镜像面所引起的无序，观察到的数据几乎同样与两种可能的分子构象相容。这两种模型都是由四个几乎平面的锯齿形单元组成，每个单元有四个原子，在连续的单元之间有一个共同的原子，但是由共同原子形成的CC键的构象在一个模型中都是反斜的，在另一个模型中都是顺斜的。给出了将语法倾斜模型视为更可能的原因。
Cyclododecane crystallises at room temperature in the monoclinic system, a = 13.27 A, b = 8.28 A, c = 5.44 A, β = 99° 32′ (Z = 2), space group C2/m. The crystal structure was determined from the three-dimensional PATTERSON function and refind by three-dimensional difference syntheses. Because of the large temperature factor and of disorder arising from the presence of statistical mirror planes at y = 0 and y = ½, the observed data are almost equally compatible with two possible molecular conformers. Both of these are built of four nearly planar zig-zag units each of four atoms, with an atom shared in common between successive units, but the conformations about the CC bonds formed by the common atoms are all anti-skew for one model and all syn-skew for the other. Reasons are given for regarding the syn-skew model as the more likely.