Iridium complexes mercury compounds

Hydrogenation using the rhodium complex may involve the formation of colloid particles, as it was shown that the reaction is inhibited by metallic mercury [167]. Selective hydrogenation of the carbonyl group in a,P-unsatu-rated carbonyl compounds can be done with immobilized ruthenium or iridium complexes by using either the supported aqueous phase technique... 

For organometailic compounds, the situation becomes even more complicated because the presence of elements such as platinum, iron, and copper introduces more complex isotopic patterns. In a very general sense, for inorganic chemistry, as atomic number increases, the number of isotopes occurring naturally for any one element can increase considerably. An element of small atomic number, lithium, has only two natural isotopes, but tin has ten, xenon has nine, and mercury has seven isotopes. This general phenomenon should be approached with caution because, for example, yttrium of atomic mass 89 is monoisotopic, and iridium has just two natural isotopes at masses 191 and 193. Nevertheless, the occurrence and variation in patterns of multi-isotopic elements often make their mass spectrometric identification easy, as depicted for the cases of dimethylmercury and dimethylplatinum in Figure 47.4. 

The metal compounds found by BP to enhance the activity of an iridium catalyst fall into two categories (i) carbonyl or halocarbonyl complexes of tungsten [117,119], rhenium [118,119], ruthenium [116,117,119], and osmium [116,117,119] (ii) simple iodides of zinc, cadmium, mercury,... 

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