Electrospray mass spectrometric studies of a potential antitumor drug and its analogous platinum(II) and platinum(IV) complexes with the ethylenediamine-N,N′-di-3-propanoato ligand and its dibutyl ester

The electrospray mass spectrometric (ESI–MS) behavior of the complexes trans -dichloro(ethylenediamine- N , N ′-di-3-propionato)platinum(IV), trans -dibromo(ethylenediamine- N,N ′-di-3-propionato)platinum(IV), dichloro(ethylenediamine- N,N ′-di-3-propionic acid)platinum(II), tetrachloro( O , O ′-di- n -butyl-ethylenediamine- N,N ′-di-3-propanoate)platinum(IV), chlorotribromo( O , O ′-di- n -butyl-ethylenediamine- N , N ′-di-3-propanoate)platinum(IV), and dichloro( O , O ′-di- n -butyl-ethylenediamine- N , N ′-di-3-propanoate)platinum(II), with the formulae trans -[PtCl 2 (eddp)] ( 1 ), trans -[PtBr 2 (eddp)] ( 2 ), [PtCl 2 (H 2 eddp)] ( 3 ), [PtCl 4 (Bu 2 eddp)] ( 4 ), [PtBr 3 Cl(Bu 2 eddp)] ( 5 ), and [PtCl 2 (Bu 2 eddp)]·H 2 O ( 6 ), is reported. The deprotonated molecular ions or halide adducts are usually observed. ESI–MS data demonstrate the usefulness of the method for efficient characterization of metal complexes in solution. Graphical Abstract