Interaction of the antitumor agent vanadocene dichloride with phosphate buffered saline

EPR study has shown that in aqueous solution the anticancer agent vanadocene dichloride (Cp2VCl2) interacts with phosphates contained in phosphate buffered saline (PBS). Chelate complex Cp2VO2PO2H (|Aiso(V)|=189.0 MHz, |aiso(P)|=81.5 MHz and giso=1.9862) is only one paramagnetic compound formed at the range about the physiological pH (6.3–7.8). Its structure was validated by comparison of observed and theoretical calculated HFC tensor (at the density functional level of theory).