Mihelj Tea, Tomašić Vlasta, Biliškov Nikola, Liu Feng
Department of Physical Chemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb, Croatia.
Department of Physical Chemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb, Croatia.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Apr 24;124:12-20. doi: 10.1016/j.saa.2013.12.092. Epub 2014 Jan 2.
18-crown-6 ether (18C6) complexes with the following anionic surfactants: sodium n-dodecylsulfate (18C6-NaDS), sodium 4-(1-pentylheptyl)benzenesulfonate (18C6-NaDBS); and potassium picrate (18C6-KP) were synthesized and studied in terms of their thermal and structural properties. Physico-chemical properties of new solid 1:1 coordination complexes were characterized by infrared (IR) spectroscopy, thermogravimetry and differential thermal analysis, differential scanning calorimetry, X-ray diffraction and microscopic observations. The strength of coordination between Na(+) and oxygen atoms of 18C6 ligand does not depend on anionic part of the surfactant, as established by thermodynamical parameters obtained by temperature-dependent IR spectroscopy. Each of these complexes exhibit different kinds of endothermic transitions in heating scan. Diffraction maxima obtained by SAXS and WAXS, refer the behavior of the compounds 18C6-NaDS and 18C6-NaDBS as smectic liquid crystalline. Distortion of 18C6-NaDS and 18C6-KP complexes occurs in two steps. Temperature of the decomplexation of solid crystal complex 18C6-KP is considerably higher than of mesophase complexes, 18C6-NaDS, and 18C6-NaDBS. The structural and liquid crystalline properties of novel 18-crown-ether complexes are function of anionic molecule geometry, type of chosen cation (Na(+), K(+)), as well as architecture of self-organized aggregates. A good combination of crown ether unit and amphiphile may provide a possibility for preparing new functionalized materials, opening the research field of ion complexation and of host-guest type behavior.
合成了18-冠-6醚（18C6）与以下阴离子表面活性剂形成的配合物：正十二烷基硫酸钠（18C6-NaDS）、4-（1-戊基庚基）苯磺酸钠（18C6-NaDBS）；以及苦味酸钾（18C6-KP），并对其热性质和结构性质进行了研究。通过红外（IR）光谱、热重分析和差示热分析、差示扫描量热法、X射线衍射和显微镜观察对新型1:1配位配合物的物理化学性质进行了表征。通过温度依赖红外光谱获得的热力学参数表明，Na(+)与18C6配体中氧原子之间的配位强度不取决于表面活性剂的阴离子部分。在加热扫描过程中，这些配合物中的每一种都表现出不同类型的吸热转变。小角X射线散射（SAXS）和广角X射线散射（WAXS）获得的衍射最大值表明，化合物18C6-NaDS和18C6-NaDBS具有近晶型液晶行为。18C6-NaDS和18C6-KP配合物的畸变分两步发生。固体晶体配合物18C6-KP的解络合温度明显高于中间相配合物18C6-NaDS和18C6-NaDBS。新型18-冠醚配合物的结构和液晶性质是阴离子分子几何形状、所选阳离子类型（Na(+)、K(+)）以及自组装聚集体结构的函数。冠醚单元与两亲体的良好组合可能为制备新型功能化材料提供可能性，从而开启离子络合和主客体型行为的研究领域。
