“New blue fluorescent Zinc(II) complexes with high quantum yield based on tuneable 1,3-substituted-imidazo[1,5-a]pyridine ligands

New Zinc(II) complexes have been synthesized and studied employing fluorescent 1,3-substituted imidazo[1,5-a]pyridine derivatives introducing both electron-donating and electron-withdrawing moieties in position 3 on the ligand skeleton. The obtained compounds have been characterized with different spectroscopic techniques, their structure has been defined by single-crystal X-ray diffraction, mass spectrometry and elemental analysis, their optical properties have been discussed in relation to their chemical structures. The comparison between the emission spectra of the free ligand and corresponding Zinc(II) complexes shows an intense hypsochromic shift, due to the modification of the ligands conformation upon metal coordination, and an extraordinary increment of the quantum yield after complexation.