Hydrolysis of cis- and transplatin: structure and reactivity of the aqua complexes in a solvent free environment. Issue 26 (10th March 2017) - Corinti, Davide
Abstract : Vibrational spectroscopy and ligand exchange reactivity allows unambiguous discrimination of singly and doubly aquated species from cis- and transplatin, highlighting elementary events at the basis of anticancer action. Abstract : Singly aquated and diaquated species are key intermediates in the mechanism responsible for the antitumor activity of cisplatin. Aqua complexes [PtX(NH3 )2 (H2 O)] + (X = Cl, OH), obtained in water by hydrolysis of cisplatin and of the inactive isomer transplatin, are transferred into the gas-phase by electrospray ionization. The so-formed ions, cis - and trans -[PtX(NH3 )2 (H2 O)] +, have been allowed to react with selected ligands, representing platination targets in the biological environment. The reaction kinetics monitored in the gas-phase show consistently higher reactivity for the chloro complexes, [PtCl(NH3 )2 (H2 O)] +, with respect to the hydroxo counterparts, [Pt(OH)(NH3 )2 (H2 O)] + . The latter species, both cis - and trans -isomers, have been assayed by IRMPD spectroscopy in the NH/OH stretching region and their vibrational and geometric features are compared with the ones pertaining to the already described chloro complexes, cis - and trans -[PtCl(NH3 )2 (H2 O)] + .