Grześkiewicz Anita M, Ostrowska Agata, Kubicki Maciej
Department of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
Acta Crystallogr C Struct Chem. 2020 Mar 1;76(Pt 3):250-257. doi: 10.1107/S2053229620001692. Epub 2020 Feb 13.
The crystal structures of 6-aminothiocytosine (systematic name: 4,6-diamino-1,2-dihydropyrimidine-2-thione, DAPMT, CHNS), its hemihydrate (0.5HO) and its dimethylformamide (DMF, CHNO) monosolvate were compared, and the influence of the type of solvent on the supramolecular motifs was analysed. In all three crystal structures, there are two symmetry-independent molecules (A and B), and these molecules are connected by three relatively short and directional hydrogen bonds to form chains of alternating A and B molecules. A further organization of these chains is dependent on the nature of the solvent molecule. In the unsolvated form, two orientations of the neighbouring chains are observed, and similar motifs - but only one per structure - can be observed in the solvated structures. These two different motifs can be connected by two different kinds of contacts, i.e. either π-π (hemihydrate) or staple-supported S...S (DMF). In the crystal structures, the O atoms of the solvent molecules are double acceptors of the same type of hydrogen bonds and bind the chains of DAPMT molecules into different motifs (dimeric or infinite chains). A Hirshfeld fingerprint analysis was used for visualization and additional interpretation of these results.
比较了6-氨基硫代胞嘧啶（系统名称：4,6-二氨基-1,2-二氢嘧啶-2-硫酮，DAPMT，CHNS）、其半水合物（0.5H₂O）及其二甲基甲酰胺（DMF，CH₃NO）单溶剂化物的晶体结构，并分析了溶剂类型对超分子基序的影响。在所有三种晶体结构中，存在两个对称独立的分子（A和B），这些分子通过三个相对较短且有方向性的氢键相连，形成由A和B分子交替排列的链。这些链的进一步组织取决于溶剂分子的性质。在无水形式中，观察到相邻链的两种取向，并且在溶剂化结构中可以观察到类似的基序——但每个结构只有一种。这两种不同的基序可以通过两种不同类型的接触连接，即π-π（半水合物）或订书钉支撑的S...S（DMF）。在晶体结构中，溶剂分子的O原子是同类型氢键的双受体，并将DAPMT分子链结合成不同的基序（二聚体或无限链）。使用Hirshfeld指纹分析对这些结果进行可视化和进一步解释。
