Cheng Yuan, Chen Lu-Sheng, Liu Qi-Kui, Wu Jun, Guo Dian-Shun
Department of Chemistry, Shandong Normal University, Jinan 250014, People's Republic of China.
Acta Crystallogr C. 2011 Jul;67(Pt 7):o244-8. doi: 10.1107/S0108270111019895. Epub 2011 Jun 23.
The molecule of 3-(2-amino-6-chloropyrimidin-4-yl)-1,1-dimethylprop-2-yn-1-ol monohydrate, C(9)H(10)ClN(3)O·H(2)O, (I), shows a very polarized molecular-electronic structure, while the polarization is slight for 3-[2-amino-6-(3-hydroxy-3,3-dimethylprop-1-yn-1-yl)pyrimidin-4-yl]-1,1-dimethylprop-2-yn-1-ol, C(14)H(17)N(3)O(2), (II). In the supramolecular structure of (I), a combination of hard N-H···N hydrogen bonds and soft C-H···N hydrogen bonds creates a molecular column. Aromatic π-π stackings between the pyrimidine rings stabilize the column with perpendicular and centroid-centroid distances of 3.283 (3) and 3.588 (1) Å, respectively. Short Cl···Cl contacts further link neighbouring molecular columns, creating a hydrophilic tube in which water molecules are fixed by various hydrogen bonds. In the packing of (II), a one-dimensional molecular chain is formed through several contacts involving hard N-H···O(N) and O-H···O(N) and soft C-H···O hydrogen bonds. Interchain O-H···O hydrogen bonds link the chains giving a two-dimensional stepped network. It is anticipated that study of the influence of hydrogen bonding on the patterns of base pairing and molecular packing in aminopyrimidine structures will shed significant light on nucleic acid structures as well as their functions.
3-(2-氨基-6-氯嘧啶-4-基)-1,1-二甲基丙-2-炔-1-醇一水合物，C(9)H(10)ClN(3)O·H(2)O，(I)的分子呈现出非常极化的分子电子结构，而对于3-[2-氨基-6-(3-羟基-3,3-二甲基丙-1-炔-1-基)嘧啶-4-基]-1,1-二甲基丙-2-炔-1-醇，C(14)H(17)N(3)O(2)，(II)，其极化程度较小。在(I)的超分子结构中，硬N-H···N氢键和软C-H···N氢键的组合形成了一个分子柱。嘧啶环之间的芳香π-π堆积稳定了该柱，垂直距离和质心-质心距离分别为3.283(3) Å和3.588(1) Å。短的Cl···Cl接触进一步连接相邻的分子柱，形成一个亲水管，其中水分子通过各种氢键固定。在(II)的堆积中，通过涉及硬N-H···O(N)、O-H···O(N)和软C-H···O氢键的几种接触形成了一维分子链。链间O-H···O氢键连接这些链，形成二维阶梯网络。预计对氢键对氨基嘧啶结构中碱基配对模式和分子堆积的影响的研究将为核酸结构及其功能提供重要的启示。
