Di‐n‐butyltin(IV) derivatives of bis(carboxymethyl)benzylamines: synthesis, NMR and X‐ray structure characterization and in vitro antitumour properties

Four di‐n‐butyltin(IV) derivatives of bis(carboxymethyl)benzylamines were synthesized and their structure characterized by 1H,13C and ­117/119Sn NMR, Mössbauer spectroscopy and mass spectrometry. The derivative substituted in the meta position by a methyl group has been further characterized by X‐ray crystallography. This compound exhibits a distorted trigonal bipyramidal geometry at tin. The NMR data in solution, as well as other spectroscopic results in the solid state, confirm this structure for all the compounds. Evidence is provided to show that the compounds are more highly associated in concentrated solution than in the solid state. Their in vitro antitumour activity is reported.