Determination of stability constants of metal complexes from NMR chemical shifts and relaxation rates using a spreadsheet computer program

✍ Scribed by Jurriaan Huskens; Hendrik Lammers; Herman van Bekkum; Joop A. Peters

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 706 KB
• Volume: 32
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260321109

✦ Synopsis

Abstract

The versatility of multinuclear magnetic resonance techniques in the determination of stability constants of metal complexes is demonstrated for three cases in which potentiometry is impossible or less suitable. The complexation of cyclo‐trimetaphosphate to lanthanide aminopolycarboxylate complexes was investigated in a dilution experiment using ^31^P NMR shifts. The stabilities of CdL and CdL~2~ [L = 1‐(2‐aminoethylamino)‐1‐deoxy‐D‐galactitol] were determined by ^113^Cd NMR speciation, in which the occurring species were in slow exchange. Competition experiments using both ^31^P NMR shifts and ^13^C and ^31^P relaxation rate enhancements were performed to determine the stabilities of Nd(NTA)(PPP) and Nd(PPP)~2~ (PPP = tripolyphosphate). Where possible, the results were compared with potentiometric data and found to be in good agreement.