“…, Pb 2? [20], lanthanide cations [23] with amino acids, adenosine and its phosphate derivatives, heterocyclic and aromatic rings [19,21,22], aminocarboxylates and aza-crown ethers [23] and the ligands containing carboxylate, phenol, amine, ether, and alcohol functional groups [20] in water. Predictive QSPR models have been developed for the stability constants of the 1:1 [9,24,25] and 1:2 [25] complexes of Sr 2?…”