摘要:
The stability constants of the complexes of one oligophosphonic acid (ethane1,1,2-triphosphonic acid 1), five phosphonocarboxylic acids (ethane-1,2-diphosphono1-carboxylic acid 2, propane-1,1-diphosphono-2,3-dicarboxylic acid 3, ethane1,2-diphosphono-1,2-dicarboxylic acid 4, ethane-1-phosphono-1,2-dicarboxylic acid 5, and propane-1-phosphono-1,2,3- tricarboxylic acid 6), and ethane-1,1,2tricarboxylic acid 7 with Cu(2+), Ni(2+), Zn(2+), Cd(2+) and Ca(2+) were determined by pH-metric titrations. The six ligands of type HNL (N= 4-6) form mononuclear MLHn (n = 0, 1,..., N-1) complexes with chelate structure. The calcium complexes seem to be less stable than the transition metal complexes.