Synthesis, characterization and near-infrared photoluminescent studies of diethyl malonate appended mono-porphyrinate lanthanide complexes

A new unsymmetrical diethyl malonate appended porphyrin and its Yb3+, Er3+ and Nd3+ complexes were prepared and characterized by elemental analysis, NMR, IR, UV-visible and mass spectral methods. The results revealed that the porphyrinate behaved as a tri-deprotonated hexadentate ligand with the appended diethyl malonate group coordinated to the lanthanide ion as an anion. Photoluminescent studies showed that the porphyrin ring transferred the absorbed visible light to the metal ions, which led to emission characteristic of the lanthanide ions in the nearinfrared region. The factors affecting the emission intensity were also investigated.