Titanium complexes spectra

Non-platinum metal complexes with antitumour activity in murine screens are known for a wide diversity of structural types and the transition metals most studied include rhodium, ruthenium, gold, copper and titanium. The spectrum of activity is generally different to cisplatin (Ti, Au) and in some cases the complexes show lack of cross-resistance with cisplatin-resistant lines. 

FIGURE 3.9 EPR of titanium citrate. The citrate complex of the Ti(III) ion at pH 9 is a general-purpose strong reductant of metalloproteins. This 3d system gives an S = 1/2 EPR spectrum with. -values just below ge. The axial signal below 3300 gauss is from Ni(I) in factor F-430. 

This complex, while sensitive to oxygen and moisture, is stable for extended periods either neat or in solution. Its carbonyl stretching band (approx. 1610 cm-) in the IR spectrum in dilute solution clearly indicates a chelate structure, which endows the carbon-titanium bond of this complex with very high stability, as compared with that of simple alkyltrichlorotitaniums [25]. 

All but one of the reactions in Figure 4 lead to the formation of the soluble TiO + ion this seems consistent with the observed changes in the visible absorption spectrum of the solid electrode. It may also be that other titanium species are formed in solution, such as peroxytitanium complexes like H Ti05 We have no direct evidence as to the identity of the solution species at this time, and have limited the candidate corrosion reactions shown in Figure 4 to those for which thermodynamic data are readily available. Nonetheless, the fact that titanium is observed in the electrolyte only upon extensive photocorrosion (and then in smaller amounts than strontium) suggests that the initial photocorrosion process involves the loss of strontium from the SrTi03, with the formation of Sr(0Ac)2 or SrSO. ... 

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