1-烷基-3-甲基咪唑溴化盐离子液体的晶体结构及性能  

Crystal structures and properties of the ionic liquid 1-alkyl-3-methylimidazolium bromides

作　　者：魏西莲[1] 魏增斌[1] 傅式洲[1] 刘杰[1] 孙德志[1] 尹宝霖[1] 王大奇[1] 王素娜[1] 王慧[1] 吴明周[1] 李干佐[2] 

机构地区：[1]聊城大学化学化工学院,聊城252059 [2]山东大学胶体与界面化学教育部重点实验室,济南250100

出　　处：《中国科学：化学》2010年第8期1072-1079,共8页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(20673050);山东省自然科学基金(2006B05)资助

摘　　要：以不同链长溴代烷烃和N-甲基咪唑反应得到1-烷基-3-甲基咪唑溴化盐,用元素分析和核磁共振对化合物进行了表征.室温下用溶剂蒸发法得到了单晶,并用X射线单晶衍射法测定了晶体结构,该晶体属于三斜晶系,空间群为P-1.化合物采用双分子层结构,水分子参与结构的形成,整个化合物由交叉的线性烷基链、咪唑头基、溴离子和水分子组成,溴离子和水分子之间较强的氢键作用在(010)方向上形成了一个无限的O-H···Br氢键链.用偏光显微镜、差示扫描量热(DSC)技术研究了其液晶行为,证明其一水合物为近晶相热致液晶.液晶区域的温度范围较宽说明水分子起到稳定作用.1-Alkyl-3-methylimidazolium bromides were synthesized via the reaction of methylimidazole and 1-bromoalkane with different alkyl chain lengths. The compounds were characterized by elementary analysis and nuclear magnetic resonance （NMR）. Single crystals of the compounds were got with solvent vaporization at room temperature,and their structure was determined by single-crystal X-ray diffraction. The crystals belong to triclinic system,P-1 space group. The crystals were formed by double molecular layers,participated by water molecules. The whole structure is made up of cross linear alkyl chains,imidazolium headgroups,bromide ions,and water molecules. Bromide ions and water molecules form an infinite O-H···Br hydrogen bond chain in （010） plane. Their liquid crystal properties were investigated by polarizing optical microscopy （POM） and differential scanning calorimetry （DSC）,which showed that the monohydrates formed thermotropic smectic liquid crystals. The temperature range of mesophase is rather wide,showing that water molecules are incorporated to make stabilizing effect.

关 键 词：离子液体晶体 晶体结构 液晶性能 热力学性能 

分 类 号：O626.23[理学—有机化学]