Structure, radiopharmaceuticals

Schmall, B. Bigler, R. E. Radiopharmaceuticals, Structure-Activity Relationships, Spencer, R. P., Ed. Grune Stratton New York, 1981 pp 769 -800. 

Werner s coordination theory, 1, 6 Whewellite structure, 6, 849 Wickmanite structure, 6, 849 Wilkinson s catalyst, 6, 239 Wilson s disease, 5, 721 copper, 6,648 removal, 6,769 copper complexes, 2,959 copper metabolism, 6,766 radiopharmaceutical agents, 6,968 Wolfram s red salt, 5,427 Wurzite... 

Acknowledging the important part that 99mTc(V) radiopharmaceuticals are playing in nuclear medicine, advances in their coordination chemistry, as attained by new syntheses and better structural characterization, are discussed with respect to the design of Tc(V) radiotracers. In the light of current interest in making technetium complexes active in vivo, a chapter considering several aspects of reactivity is included. 

In the bifunctional radiopharmaceuticals, Tc and Re complexes that are suitable for coupling to antibodies are almost square-pyramidal oxo complexes of tetradentate ligands, as mentioned earlier. Spies et al. [65] recently studied the syntheses and structures of rhenium complexes with a tetradentate NS3 tripod ligand 2, 2,, 2"-nitrilotris(ethanethiol) (l in Fig. 9) as an interesting alternative to the oxo complex. Such ligands could lead to weakly polar, trigonal-bipyramidal complexes in which the metal atom is more strongly shielded than in the square-pyramidal oxo complexes. Schemes for the syntheses... 

The gallium and indium complexes of novel bis(thiosemicarbazones) have been investigated.71-73 Initial publications indicated a more complex stoichiometry where X-ray crystal structures suggested either dinuclear or trinuclear complexes. Whereas these complexes are quite interesting, they are less likely to result in useful nuclear medicine radiopharmaceuticals. The bis(thiosemi-carbazones) are quite useful as ligands for copper, and are discussed in more detail vide infra). 

Metal-essential radiopharmaceuticals are those whose targeting properties are inherent in the structure and chemistry of the complex itself rather than a biomolecule whose targeting ability is independent of the attachment of the metal. While this class of tracers includes many well-developed technetium complexes, it includes relatively few rhenium complexes. 

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