Mechanochemical treatment, materials prepared

Equally effective was the complexation of C70 by HSVM (lOmin, Cjq j-cyclodextrin 1 8), while the other functionalized C50 derivatives afforded water-soluble 1 1 complexes, since functional groups prevent the formation of the bicapped 1 2 complexes. By mechanochemical treatment, fullerene 50 also complexes with sulfocalix[8]arene (lOmin, equimolar amounts), and the obvious advantage of the solid-state complexation is illustrated by the complexation of sulfocalix [8]arene with fullerene dimer (also prepared by mechanosynthesis, see chapter Applications of Ball Milling in Nanocarbon Material Synthesis). Dimer is hardly soluble in most common organic solvents, but the mechanochemical treatment of an equimolar mixture of sulfocalix[8]arene and fullerene dimer for lOmin afforded bicapped complex, which is about twice more soluble in water than in commonly used ODCB. 

Millet, R, Hwang, T. (1996). Preparation of TiB and ZrB - Influence of a mechanochemical treatment on the borothermic reduction of titania and zirconia. Journal of Materials Science, 31, 351-355. doi 10.1007/BF01139151. 

Finally, mechanochemical synthesis offers a solvent-free route for the preparation of MOFs by ball milling of starting components [23-28]. Sufficient amounts of pure material for broad-range testing can be easily obtained from this method. Furthermore, the solid-solid reaction typically produces quantitative yields and leads directly to products in powder form. Hence, the materials are ready for various applications without the need for time-consuming treatments. Mechanochemistry as an approach for the synthesis for one-, two-, and three-dimensional metal-organic compounds is currently employed by several groups, who mainly focus on the synthesis of new structures. 

Example 3 Synthesis of multi-component complex compounds A nmnber of materials such as some lead-containing complex oxides are very difficult to prepare in the form of pine phase. Powder of Pb(Znj,.Mgi jt)i/3Nb2/303 was obtained by soft-mechanochemical procedure, that is, by milling of a stoichiometric mixture of PbO, Mg(OH)2, Nb20s and 2Zn(OH)2 H2O in a multi-ring-type mill up to 3 h. Partial formation of desired phase with perovskite structure already took place during milling. Subsequent heat treatment at 1000°C for 1 h yielded pure perovskite phase. 

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