Potentiometric studies of binary and ternary complexes involving cadmium(II) and nitrilo-tris(methyl phosphonic acid) with amino acids, peptides and DNA constituents

Ann Chim. 2007 Aug;97(8):733-45. doi: 10.1002/adic.200790057.

Abstract

The complexing properties of nitrilo-tris(methylphosphonic acid) (NTP) with cadmium(II) were investigated pH-metrically at 25 degrees C and at ionic strength of 0.1 mol dm(-3) (NaNO3). Stoichiometry and stability constants for the complexes formed are reported. Cadmium (II) forms Cd(NTP)(4-) and the corresponding hydroxy complexes. The ternary complexes are formed in a stepwise mechanism whereby NTP binds to cadmium(II), followed by coordination of amino acids, peptides or DNA. The concentration distribution of the various complex species has been evaluated.

MeSH terms

  • Amino Acids / chemistry*
  • Cadmium / chemistry*
  • Chelating Agents / chemistry*
  • DNA / chemistry*
  • Hydrogen-Ion Concentration
  • Organophosphorus Compounds / chemistry*
  • Peptides / chemistry*
  • Potentiometry / methods*

Substances

  • Amino Acids
  • Chelating Agents
  • Organophosphorus Compounds
  • Peptides
  • Cadmium
  • (nitrilotris(methylene))triphosphonic acid
  • DNA