【摘要】 本文用量热滴定研究了N-苄基-单氮杂-15-冠-5与稀土(Ⅲ)硝酸盐(La,Ce,Pa,Nd,Sm,En,Gd,Tb,Dy,Ho,Er,Yb)和N-苄基-单氮杂-18-冠-6与稀土(Ⅲ)硝酸盐(La和Co)在无水乙腈溶液中,298.15 K时配位作用的热力学性质、化学计量法表明,所有稀土硝酸盐均与臂式冠醚形成1∶1配合物.实验中,由联接的计算机直接算出了配合物的稳定常数和配位反应的热焓,进而算出了配位自由能和配位熵.从热力学的观点,讨论了冠醚环的尺寸效应、空间构型等对配位稳定性的影响.更多还原

【Abstract】 Calorimetric titrations were performed in anhydrous acetonitrile at 298.15K to give the complex stability constants (K_s) and the thermodynamic parameters for the complexation of rare earth (Ⅲ) nitrates (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) with 2V-benzyl-monoaza-15-crown-5 and of rare earth(Ⅲ) nitrates (La, Ce) with N-benzyl-monoaza-18-crown-6. The complexation stoichiometry is 1:1 for all rare earth (Ⅲ) nitrates. The complex stability constants (K_s), reaction enthalpies (△H~0) and entropies (T△S~0) were calculated directly by using precision calorimeter connected to an Apple Ⅱ microcomputer. The effects of the crown ether’s size-fit concept, spatial arrangement and other major factors upon complex stability are discussed from a viewpoint of thermodynamics.更多还原