Free metal ion depletion by “good's” buffers: III. N-(2-acetamido)iminodiacetic acid, 2:1 complexes with Zinc(II), Cobalt(II), Nickel(II), and Copper(II); Amide deprotonation by Zn(II), Co(II), and Cu(II)

✍ Scribed by Edward A. Lance; Charles W. Rhodes III; Robert Nakon

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 740 KB
• Volume: 133
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(83)90115-x

✦ Synopsis

Potentiometric, visible, infrared, electron spin, and nuclear magnetic resonance studies of the complexation of N-(2-acetamido)iminodiacetic acid (H2ADA) by Ca(II), Mg(II), Mn(II), Zn(II), Co(II), Ni(II), and Cu(II) are reported. Ca(II) and Mg(II) were found not to form 2:1 ADA2- to M(II) complexes, while Mn(II), Cu(II), Ni(II), Zn(II), and Co(II) did form 2:1 metal chelates at or below physiological pH values. Co(II) and Zn(II), but not Cu(II), were found to induce stepwise deprotonation of the amide groups to form [M(H-1ADA)4-(2)]. Formation (affinity) constants for the various metal complexes are reported, and the probable structures of the various metal chelates in solution are discussed on the basis of various spectral data.