NMR study of 1,7-diamino-4-oxyheptane-1,1,7,7-tetraphosphonic acid interaction with samarium(III) cation

1,7-Diamino-4-oxypentane-1,1,7,7-tetraphosphonic acid has been synthesized while searching for potential components for ¹⁵³Sm radiopharmaceuticals. Its interaction with samarium(III) cation has been studied by ¹³C and ³¹P NMR spectroscopy in comparison with 1,5-diamino-3-oxypentane-N,N'-tetra-(methylenephosphonic acid) which is the ligand component of the osteotropic drug Samarium ¹⁵³Sm oxabifore. NMR spectroscopy provides a simple, convenient, and informative method for studying interactions between the ligand and prospective radionuclide cation.