• 作者： 劉春櫻; 孫炳榕
• 作者服務機構： Department of Chemistry, National Taiwan University
• 中文摘要： A cyclic hydroxamic acid, 2-hydroxyquinoline-N-oxide and an aromatic hydroxamic acid, benzohydroxamic acid were obtained in the form of free acids. Their acid dissociation constants and a total of seventy of the formation constants for twenty five complexes formed by these two hydroxamic acids with rare earth metals and yttrium in aqueous solution have been determined by Bjerrum potentiometric titration technique.
  The titration medium was maintained at ionic strength of 0.1M by sodium perchlorate and at a temperature of 25℃±0.1°.
  In general log K1>log K2>log K3 for a given metal ion are observed, but the difference in the value between these three constants are not much, indicating that there is almost equal tendency for the formation of complex species.
  For the trends in the series of rare earth metal complexes of these two reagents, the formation constants increase fairly regularly with decrease in ionic radius and the “gadolinium break” is also observed as usual. The trends for the elements heavier than gadolinium follows the pattern of the third group of the ligands as classidied by T. Moeller et. al. , showing an increase with the first element beyond gadolinium and then a slight decrease toward lutetium.
• 英文摘要： --
• 中文關鍵字： --
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