Manganese complex immobilisation

Crabtree et al. reported the immobilisation of the dimeric mixed-valence species [(tpy)(H20)Mn (0)2Mn (tpy)(H20)] (5) onto titanium dioxide nanoparticles with different degrees of crystallinity. The complex was directly adsorbed onto the titanium dioxide surface for ciystalline titanium dioxide, the manganese(iii)-manganese(iv) dimer transformed to manganese(iv)-manganese(iv) dimer or tetramer-like structure, whereas it remained stable when anchored to titanium-dioxide nanoparticles with low crystallinity. The o>ygen-evolution measurements performed in the presence of CAN showed that the dimeric mixed-valence complex adsorbed on amorphous titanium dioxide support was not catalytically active, whereas the oxidised/dissociated complex formed in the crystalline titanium dioxide nanoparticles showed catalytic activity however, no detailed explanation was provided for the differences in catalytic activity. ... 

Mustard has also been shown to complex with a wide variety of metal centres which are electron deficient, such as the incomplete d -orbitals of transistion metal ions. Mg, Sn, Hg, Bi, Cu, Ni, Ti, Cr, Mo, Cd, Pt, Zn, Fe and others have all been investigated in the past as means of immobilising mustard gas . More recently work has been carried out at PLSD using biomimetic systems such as the manganese dimer [6] shown below in Figure 7 to catalyse the oxidation of mustard under ambient conditions. 

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