Acta Phys. -Chim. Sin. ›› 1990, Vol. 6 ›› Issue (01): 51-56.doi: 10.3866/PKU.WHXB19900109

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Study on the Linear Free Energy Relationships,Linear Enthalpy Relationships and Linear Entropy Relationships of Cu(II)-Aminoacid Coordination Compounds in the Mixed Solvent Using Copper Ion-Selective Electrode

Chen Zi-Yuan;Shen Zhen-Wen;Huang Si-Fan;He Shi-Fang   

  1. Department of Chemistry,Shanghai Normal University,Shanghai
  • Received:1988-07-05 Revised:1989-03-15 Published:1990-02-15
  • Contact: Chen Zi-Yuan

Abstract: The stability constants of coordination compounds formed from some α-amino acids(αA) DL-P-Fluoro phenylalanine, DL-Serine, DL-Valine, DL-Alanine and α-amino-isobutyric acid with Cu(Ⅱ) were measured by Ion-Selective Electrode at 25±0.1, 35±0.1 and 45±0.1 ℃ in water, 30% ethanol and 50% ethanol solution in the presence of 0. 16 mol·dm~(-3) KNO_3. The order of stability of the Cu(Ⅱ)-αA coordination compounds is in 50% ethanol solution>in 30% ethanol solution>in waterat 35±0.1 ℃.
Linear relationships not only existed between the stability of Cu(II)-αA coordination compouds and the base strength of ligands but also existed between the formation enthalpy of coordination compounds and the protonation enthalpy of the ligands, and between the formation entropy of coordination compounds and the protonation entropy of the ligands as well.
25—45 ℃ ΔH~...