Ruthenium, high nuclearity carbonyl synthesis

Finally, the surface-mediated synthesis of ruthenium carbonyl complexes has also been used to prepare supported ruthenium particles. Using silica as a reaction medium and conventional salts, apart from Ru3(CO)i2, mononuclear Ru(CO)j, and high nuclearity carbonyl-derived species can be obtained by CO reductive carbonylation [127, 128]. This opens new routes to preparing tailored supported ruthenium particles. 

Fig. 5.4 depicts some results obtained in the first stages (high nuclearity complexes formation) of the synthesis in xylene solvent which leads to the formation of nanostructured powders, RuxSey, from tris-ruthenium dodeca-carbonyl (Ru3(CO)i2) and elemental selenium dissolved in an organic solvent (xylene). After 40 minutes of reaction, l3C-NMR spectrum (Fig. 5.4 (c)) puts in evidence the formation of a new polynuclear chemical precursor with a chemical shift 8 of 198.89 ppm (i.e., Ru4Se2(CO)n)- Selenium takes part in the coordination sphere. The peak intensity with the chemical shift of 199.67 ppm, corresponds to the initial chemical precursor which decreases as a function of the synthesis reaction time (Fig. 5.4(a)). Other chemical shifts (with minor peak intensities) on both sides of the 13C-NMR spectrum, which put in evidence the complex interplay of the reaction, are also observed. 

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