溶剂对磺胺甲基嘧啶溶剂化合物形成的影响

Effects of solvent on formation of sulfamerazine solvates

采用悬浮转化法对磺胺甲基嘧啶溶剂化合物在醇类、酯类和酰胺类等17种溶剂中进行了筛选研究,采用粉末X射线衍射、热重分析、扫描电镜和傅里叶红外光谱对磺胺甲基嘧啶溶剂化合物进行了表征,成功制备出磺胺甲基嘧啶与N,N-二甲基甲酰胺、N,N-二甲基乙酰胺、N-甲基吡咯烷酮溶剂化物和二甲基亚砜的4种溶剂化合物。热重结果表明它们均属于化学计量比为1∶1的溶剂化合物;扫描电镜分析发现在溶剂化合物形成过程中,晶体的形态由接近正方体的块状晶体变为片状与棒状晶体;傅里叶红外表征分析证实了溶剂化合物中溶剂与溶质分子形成分子间氢键。分析所用的17种溶剂的分子结构、氢键供体和受体能力等性质,确定了磺胺甲基嘧啶容易与氢键受体能力强的溶剂形成相应溶剂化合物。对比分析了晶体中分子的堆积效率,进一步证实了磺胺甲基嘧啶形成氢键溶剂化合物。根据磺胺甲基嘧啶和溶剂化合物的单晶结构,分析氢键溶剂化合物形成前后分子堆积、结构合成子和氢键网络的变化,磺胺甲基嘧啶晶型Ⅱ及其溶剂化合物的四种结构中均形成一维的椅子形氢键网络,对于三种溶剂化合物,除了磺胺甲基嘧啶分子间形成的氢键网络,磺胺甲基嘧啶分子氨基中另一个氢原子与溶剂分子的氧原子相连形成分子间N-H…O氢键。结果表明氢键在溶质与溶剂间的超分子自组装过程中起决定作用,是影响溶剂化合物形成的关键因素。

The solvent compounds of sulfamethylpyrimidine were screened in 17 kinds of solvents,such as alcohols,esters and amides,and the sulfamerazine solvates were investigated by powder X-ray diffraction,thermal gravimetric analysis,scanning electron microscopy and Fourier transform infrared spectroscopy.The results showed that sulfamerazine can form four solvates with N,N-dimethylformamide,N,N-dimethylacetamide,Nmethylpyrrolidone and dimethylsulfoxide respectively.TGA results showed that they all belong to the type of 1∶1 stoichiometric solvates.SEM results indicated that the morphology of the crystals changed significantly after the formation of the solvates,the morphology of the crystal changed from block shape to sheet and rod crystal.FTIR characterization analysis confirmed that the solvent and the solute molecules formed intermolecular hydrogen bonds in the solvates.The physicochemical properties of the used solvents for the screening were analyzed,and the results showed that the corresponding solvates were easy to form in the solvents with strong hydrogen bond acceptor ability.The packing efficiency of molecules in crystals further confirmed that sulfamerazine form hydrogen bond solvates.The changes of molecular packing,structure synthons and hydrogen bond network before and after the formation of solvates were determined according to the single crystal structures of compounds.Sulfamerazine formⅡand its solvates formed a one-dimensional leader hydrogen bond network.For three solvates,in addition to the hydrogen bond network formed between the molecules of sulfamerazine,another hydrogen atom in the amino group of sulfamerazine was bonded to the oxygen atom of the solvent molecule to form an intermolecular N-H…O hydrogen bond.The results showed that the hydrogen bond played a decisive role in the supramolecular self-assembly process between the solute and the solvent,then affected the formation of solvates.