Vaska-type rhodium complexes

When formaldehyde reacts with rhodium halides, carbonylation proceeds (hydrocarbonylation between formaldehyde and a ruthenium halide as described in Chapter 16 proceeds). A Vaska type rhodium complex is obtained by the reaction with phosphine as shown in eq. (18.7) [17]. 

The complex trans-RhX(CO)L2 (ref. 1) is an important type of rhodium complex, which is used as an air stable catalyst precursor in organic syntheses. A number of syntheses for these rhodium complexes have been summarized. Among recent methods of synthesis, the most useful, using RhCl(CO)L2, Ag2C03, NH4F, and MX (alkali metal salt), was reported by Vaska et al." ... 

Tuning Rhodium (I) Metal Centre A ccessibility in lodomethane Oxidative Addition to Vaska-type Complexes by Interchanging Tertiary Phosphine for Arsine and Stibine... 

It was shown that these Vaska-type complexes of rhodium(i) are excellent model complexes to study basic effects, including the use of molecular structure information to explain solution effects on reaction mechanisms. However, additional research is still required to aid in understanding solution behaviour of these systems. 

Table 1 Calculated energies for addition of H2 to rhodium Vaska-type complexes...

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