Figure 1.

Chemical structures of newly developed ligands evaluated with ⁸⁹Zr⁴⁺. The binding donor groups are highlighted in red and the conjugation points of the bifunctional ligands are shown in blue. The molecules are divided by their progress in development as monofunctional ligand which cannot be attached to a targeting vector, bifunctional ligands that have yet to be attached to a targeting vector, and bifunctional chelators which have been shown to bind a metal and have been conjugated to a targeting molecule. The ligands are further divided between those that were found to effiectively bind Zr and those that were found to be unsuitable.