Protonierte Metallkomplexe zweizähniger Liganden

Quite often some of the ligand atoms of a chelating agent are protonated while others simultaneously are attached to a metal cation. Metal‐hydrogen‐complexes of that kind have usually been neglected in the elucidation of the equilibria between the various metal ions and chelating ligands. A general method is described by which the concentration of these protonated metal complexes can be obtained. The method is applied to the six systems: Cd 2+ and Malonate (= Mal 2− ), Cd 2+ and Succinate (= Succ 2− ), Cd 2+ and Trimethylenediamine (= Triam), Cd 2+ and Tetramethylenediamine (= Tetram), Hg 2+ and Tetramethylenediamine; Hg 2+ and Pentamethylenediamine (= Pentam). The stability constants of the following complexes are given: CdMal, CdHMal + , Cd(Mal) 2 2− , CdH(Mal) 2 − , Cd(HMal) 2 ; CdSucc, CdHSucc 2 + , Cd(Succ) 2 2− ; CdTriam 2+ , CdHTriam 3+ ; CdTetram 2+ , CdHTetram 3+ ; HgTetram 2+ , HgHTetram 3+ , Hg(HTetram)   2 4+ ; CdPentam 2+ , CdHPentam 3+ , Cd(HPentam) 2 4+ .