Synthesis and photophysical studies of two luminescent chemosensors based on catechol and 8-Hydroxyquinoline chromophores, and their complexes with group 13 metal ions

Two ligands, L1 and L2, derived from 2,3-dihydroxybenzaldehyde and 8-hydroxyquinoline-2-carbaldehyde using 4,4′-methylene-dianiline as spacer have been used to study their interaction with the group 13 metals, Al3+, Ga3+ and In3+. In all cases, emissive dinuclear metal complexes were synthesized and characterized. The complexation reactions with the diiminic ligands were obtained by direct reactions between ligand and metal ions. The complexes have been characterized by elemental analyses, mass spectrometry, IR, UV–vis and fluorescence spectroscopy. The interaction towards metal ions has been explored in solution by absorption and fluorescence emission spectroscopy, obtaining results that support the solid-state helicate-type complexes.