Technetium complexes dimethylglyoxime

Dioxime type ligands can be considered as Schiff base bischelates (Deutsch et al. 1978 Bandoli et al. 1986). The first complexes with oxime ligands were described as mono-capped Tc(dioxime)3(//OH)SnCl3 (dioxime = dimethylglyoxime) complexes (Treher et al. 1989). The boronic adducts of technetium oximes - (BATOs) (Fig. 2.1.19) - were well characterized, and some could be used both as myocardial and cerebral perfusion agents. The complexes are neutral technetium is coordinated to three N-bonded dioxime molecules and to one Cl or Br atom in an axial position (seven covalent bonds). 

Deutsch E, Elder RC, Laarge BA et al (1978) Structural characterization of a bridged technetium-99-tin-dimethylglyoxime complex implication for the technetium-99m-labeled radiopharmaceuticals prepared by tin(II) reduction of pertechnetate. Proc Natl Acad Sci USA 73 653-660 Deutsch E, Glavan KA, Sodd VJ et al (1981) Cationic Tc-99m complexes as potential myocardial imaging agents. J Nucl Med 22 897-907... 

Furthermore, an undesirable side reaction between tin and technetium may occur. As outlined above, there is a high excess of tin - as Sn(II) and Sn(IV) - over technetium and this fact leads to the idea that mixed-metal complexes maybe formed in radiopharmaceutical preparations. Interest in the question, whether stannous or stannic tin could be involved in the radiopharmaceutical was further stimulated by the formation of a tin-capped Tc-dimethylglyoxime complex, Tc(oxime)3(/i-OH)SnCl3 (Deutsch et al. 1976). However, this compound was prepared under the condition of carrier-added technetium its ready conversion to uncapped species gives no evidence for the existence of mixed-metal type compounds. 

In the lower oxidation state, technetium forms a green complex with dimethylglyoxime. 

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