種々の溶媒中におけるアルカリ金属イオン及びアンモニウムイオンのクラウンエーテル錯体に関する熱力学的研究

概要

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Thermodynamic studies on the 18-crown-6 and 12-crown-4 complexes with alkali-metal and ammonium ions in various solvents were conducted. The difference in the solvation of 18-crown-6 and 12-crown-4 in various solvents was investigated by measuring the heats of solution in order to obtain the enthalpies of transfer of the ethers from water to various aprotic solvents. The complexation of 18-crown-6 and 12-crown-4 with alkali-metal and ammonium ions in acetonitrile (MeCN), propylene carbonate (PC), N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and pyridine (PY), as well as in water for 12-crown-4 was investigated by precise titration calorimetry. Also, the reaction enthalpies and entropies of the complexation were determined. Using the thus-obtained thermodynamic parameters the enthalpies of transfer of [M (18-crown-6)]^+ (M=Na^+, K^+, Rb^+, Cs^+, NH_4^+) complexes from water to various solvents and [M (12-crown-4)]^+ (M=Na^+, K^+, Rb^+, Cs^+, NH_4^+) complexes from PC to various solvents were obtained. The ^<23>Na chemical shift of [Na (18-crown-6)]^+ was measured in nitromethane, MeCN, PC, DMF, PY and water. Based on these data, a detailed discussion of the solvent effect on the complexation of 18-crown-6 and 12-crown-4-is given.
社団法人日本分析化学会の論文
1997-02-05