Synthesis and structural analysis of bioactive Schiff-base pentacoordinated diorganotin(IV) complexes

A family of pentacoordinated diorganotin(IV) compounds was synthesized and characterized through the advantageous approach of a multicomponent methodology involving the reaction between 4-(diethylamino)salicylaldehyde, dibutyltin oxide and including a series of l -amino acid fragments (alanine, valine, leucine, isoleucine, phenylalanine, tyrosine and methionine), all carried out in one-step, in excellent yields. Structures were elucidated by FTIR, HRMS and solution NMR (1H, 13C and 119Sn). Diorganotin(IV) derivatives crystallized easily and five unreported molecular structures were solved and analyzed by SC-XRD experiments; depending on the orientation of the alkyl residues different isomorphic arrays were found. Finally, pentacoordinated diorganotin(IV) complexes were tested against tumoral cell lines, HCT-15 (colon adenocarcinoma), HeLa (cervical uterine adenocarcinoma), MCF-7 (breast adenocarcinoma) and PC-3 (human prostate cancer) in order to evaluate their in vitro cytotoxicity.