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Research has been conducted on the diamine dioxime ligands' technetium complexes. The substitution of these complexes at the central carbon of the propylene bridge has been examined and the results are discussed.

The macrocyclic amino carboxylate complexes, DOTA and DO3A, serve as contrast agents for magnetic resonance imaging. Fe(DO3A).3H2O is synthesized by the reaction of Fe(OH)3 and H3DO3A in water. The resulting suspension, on being stirred and heated at 90 degree celsius for 1 hour, yields a yellow-green solid on evaporation of the solvent. Crystallographic studies of this compound reveals the molecular structure of the neutral Fe(DO3A), which shares identity with the heptacoordinate face-capped trigonal prismatic structure of In(DO3A).

Hydrogenolysis and deformylation of 10-formyl-1,4, 7-tris(benzyloxycarbonylmethyl)- 1,4,7,10-tetraazacyclododecane affords the synthesis of (1R,4R,7R)-alpha,alpha',alpha''-trimethyl-1,4,7,10- tetraazacyclododecane-1,4,7-triacetic acid (DO3MA). A pure Gd(III) chelate, Gd(DO3MA), is formed by the complex with gadolinium acetate. Structural analysis shows that the chelate crytals have three asymmetric carbons with alpha-methyl groups in (R)-configuration. The x-ray crystallographic and physicochemical properties of the chelates are discussed.