Radiopharmaceuticals are drugs based on radioisotopes designed for diagnostic and therapeutic purposes. Radiometal complexes as radiopharmaceuticals for medical imaging have received increased attention in the past decades. Coordination chemistry plays an important role in the design of these target-specific radiopharmaceuticals. It is very important to correlate all aspects of a radiometal's coordination chemistry with its in vivo behavior. Macrocyclic chelators are ligands that form stable metal complexes. In the 1990s Weisman, Wong et al. developed a new class of tetraazamacrocycles featuring ethylene cross-bridges linking nonadjacent nitrogens. These cross-bridged chelators form very inert complexes with a variety of metal cations. While most attention has been paid to their Cu(II) complexes, Ga(III) and In(III) are also potential radiometal candidates. In this work, previously inaccessible Ga(III) and In(III) complexes of a dicarboxylate cross-bridged cyclam ligand have been synthesized for the first time. Their kinetic inertness has been investigated by acid decomplexation studies. Finally, Cu(II) complexations have also been investigated incorporating microwave-assisted conditions.