Subsolidus binary phase diagram of the bilayer compounds [n-C_nH_(2n+1)N(CH_3)_3]_2ZnCl_4(n = 16, 18)  

作　　者：RUAN Bei WU Ke Zhong CHEN Jing XIONG Yuan Yuan REN Bi Yan 

机构地区：[1]Department of Chemistry and Material Science, Hebei Normal University

出　　处：《Science China Chemistry》2014年第12期1703-1707,共5页中国科学（化学英文版）

基　　金：financially supported by the National Natural Science Foundation of China(21473048,21246006);the Natural Science Foundation of Hebei Province(B2012205034);the Science Foundation of Hebei Normal University(L2011K04,L2013B07)

摘　　要：The bilayer compounds[n-CnH2n+1N(CH3)3]2Zn Cl4(n=16,18)experience solid-solid phase transition within the temperature range of 310 to 340 K.The low-temperature crystal structures of the pure compounds are characteristic of the piling effect in which a 2D macro-anion Zn Cl42- is sandwiched between two alkylammonium layers.These layers become conformationally disordered in the high-temperature phases.The structures can alternatively be viewed as a double layer of alkylammonium ions between Zn Cl42- sheets and can be considered as crystalline models of lipid bilayers.The experimental subsolidus binary phase diagram of[n-C16H33N(CH3)3]2Zn Cl4-[n-C18H37N(CH3)3]2Zn Cl4 has also been established over the whole composition range by differential scanning calorimetry(DSC)and X-ray diffraction.In the phase diagram,one intermediate compound[n-C16H33N(CH3)3][n-C18H37N(CH3)3]Zn Cl4 at WC16C3Zn%47.50 and two eutectoid invariants points at WC16C3Zn%35.10 and75.70 were observed;the respective temperatures of the two eutectoids are 320±1 and 315±1 K.In addition,there are three noticeable solid solution ranges in the phase diagram:α-phase at the left,β-phase at the right,andγ-phase in the middle.The bilayer compounds[n-CnH2n＋1N（CH3）3]2Zn Cl4（n=16,18）experience solid-solid phase transition within the temperature range of 310 to 340 K.The low-temperature crystal structures of the pure compounds are characteristic of the piling effect in which a 2D macro-anion Zn Cl42- is sandwiched between two alkylammonium layers.These layers become conformationally disordered in the high-temperature phases.The structures can alternatively be viewed as a double layer of alkylammonium ions between Zn Cl42- sheets and can be considered as crystalline models of lipid bilayers.The experimental subsolidus binary phase diagram of[n-C16H33N（CH3）3]2Zn Cl4-[n-C18H37N（CH3）3]2Zn Cl4 has also been established over the whole composition range by differential scanning calorimetry（DSC）and X-ray diffraction.In the phase diagram,one intermediate compound[n-C16H33N（CH3）3][n-C18H37N（CH3）3]Zn Cl4 at WC16C3Zn%47.50 and two eutectoid invariants points at WC16C3Zn%35.10 and75.70 were observed;the respective temperatures of the two eutectoids are 320±1 and 315±1 K.In addition,there are three noticeable solid solution ranges in the phase diagram：α-phase at the left,β-phase at the right,andγ-phase in the middle.

关 键 词：lipid bilayers n-hexadecyltrimethylammonium tetrachlorozincate n-trimethylstearylammonium tetrachlorozincate phase transitions phase diagram 

分 类 号：O642.42[理学—物理化学]