Titanocene-Phosphine Derivatives as Precursors to Cytotoxic Heterometallic TiAu2 and TiM (M = Pd, Pt) Compounds. Studies of their Interactions with DNA

A series of tri- and bimetallic titanium–gold, titanium–palladium, and titanium–platinum derivatives of the general formulas [Ti{η5-C5H4(CH2)nPPh2(AuCl)}2]·2THF [n = 0 (1); n = 2 (2); n = 3 (3)] and [TiCl2{η5-C5H4κ-(CH2)nPPh2}2(MCl2)]·2THF [M = Pd, n = 0 (4); n = 2 (5); n = 3 (6) ; M = Pt, n = 0 (7); n = 2 (8); n = 3 (9)] have been synthesized and characterized by different spectroscopic techniques and mass spectrometry. The molecular structures of compounds 1–9 have been investigated by means of density functional theory calculations. The calculated IR spectra of the optimized structures fit well with the experimental IR data obtained for 1–9. The stability of the heterometallic compounds in deuterated solvents [CDCl3, dimethyl sulfoxide (DMSO)-d6, and mixtures 50:50 DMSO-d6/D2O and 1:99 DMSO-d6/D2O at acidic and neutral pH] has been evaluated by 31P and 1H NMR spectroscopy showing a higher stability for these compounds than for Cp2TiCl2 or precursors [Ti{η5-C5H4(CH2)nPPh2}2]. The new compounds display a...