Biological activity of organometallic bismuth compounds

The chemical aspects of organometallic bismuth(III) compounds are discussed with respect to the stability of the metal-carbon sigma bond, their low dipole moments, and the limited solubility of these complexes in hydrophilic solvents. A new Bi heterocycle, which is of potential interest in terms of stability and solution behaviour, was shown to exist as an intermediate under the conditions in the mass spectrometer. Although generally bismuth organic compounds are extremely toxic, in the 1970s they became important as biocides and this is still being investigated. They have also been discussed as irritation causing chemical warfare agents. While their application in chemotherapy never became very widespread because antibiotics were discovered, in the last few years the antitumor activity of some derivatives has been reported.