Hydroxo-Bridged Complexes Rhodium

HYDROXO-BRIDGED COMPLEXES OF CHROMIUM(III), COBALT(III), RHODIUM(III), AND IRIDIUM(III)... 

There are several examples of well-characterized tri- and tetranu-clear hydroxo-bridged complexes of chromium(III) and cobalt(III). Penta- and hexanuclear aqua chromium(III) complexes have been prepared in solution, but their structure and properties are unknown. Oligomers of nuclearity higher than four have not been reported for cobalt(IIl), with the exception of some hetero-bridged heteronuclear species (193, 194). There appear to be no reports of rhodium(III) or iridium(III) complexes of nuclearity higher than two. 

Hydroxo-Bridged Complexes of Chromium(III), Cobalt(III), Rhodium(III), and Iridium(III) Johan Springborg... 

Springborg J (1988) Hydroxo-bridged complexes of chromium(III), cobalt(III), rhodium(III) and iridium(III). Adv Inorg Chem 32 55-169... 

Hydroxo-Bridged Complexes of ChromiumdIIl, Cobalt(II), Rhodium(IIl), and Iridium(lII)... 

The cleavage of polynuclear hydroxo-bridged rhodium(III) and iridium(III) complexes into the corresponding mononuclear fragments has been reported in only a few instances, but the well-established tendency of mononuclear complexes of these metal ions to undergo substitution reactions with retention of configuration indicates the possibility of analytical and synthetic applications such as described above for chromium (III). 

Preliminary studies seem to indicate that acid hydrolysis of corresponding rhodium(III) complexes leads to peroxo bridge cleavage rather than hydroxo bridge cleavage (124). 

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