The Pfitzinger condensation reaction was employed to synthesise N^N sterically demanding ligands bearing carboxylic acid anchoring groups, namely 2,2΄-pyridyl-quinoline-4-carboxylic acid (pqca); 6'-methyl-2,2΄-pyridyl-quinoline-4-carboxylic acid (6'-Mepqca); 8-methyl-2,2΄-pyridyl-quinoline-4-carboxylic acid (8-Mepqca) and 8,6'-dimethyl-2,2΄-pyridyl-quinoline-4-carboxylic acid...