Different forms of antiparallel stacking of hydrogen-bonded antidromic rings in the solid state: polymorphism with virtually the same unit cell and two-dimensional isostructurality with alternating layers
作者:Alajos Kálmán、László Fábián、Gyula Argay、Gábor Bernáth、Zsuzsanna Cs. Gyarmati
DOI:10.1107/s0108768104024553
日期:2004.12.1
trans-2-hydroxycyclopentanecarboxamide (4) [Kalman et al. (2001). Acta Cryst. B57, 539-550], but in this structure (space group Pca21) the layers are stacked in parallel mode. Similar to (2a) and (2b), the antiparallel layer stacking in (3) versus their parallel array in (4) illustrates the two-dimensional isostructurality with alternating layer orientations. Although (3) and (4) display isostructurality, they
对2-羟基环烷羧酸及其羧酰胺类似物进行系统结构分析的延续,是抗环的作用[Jeffrey&Saenger(1991)。生物结构中的氢键。柏林,海德堡:斯普林格出版社]对环戊烷和环庚烷衍生物的层堆叠进行了比较。确定反式-2-羟基环庚烷羧酸(2)的结构导致发现了具有几乎相同的晶胞的两种多晶型物[Kalman et al。(2003)。J.Am. 化学 Soc。125,34-35]。(i)整个单晶的反卷环的层堆叠是反平行的(2b)。(ii)反定律环和21轴是平行的(2a),因此单晶的畴必须是反平行的。尽管它们的多态性受溶剂控制,他们说明了二维同构结构的一种新颖形式。反平行层堆叠再次由反式-2-羟基环庚烷甲酰胺(3)(空间基团Pbca)证明。它是由与同源反式-2-羟基环戊烷羧酰胺(4)中的结构同构的层组成的[Kalman et al。(2001)。Acta Cryst。B57,539-550],但是