Energy transfer process in highly photoluminescent binuclear hydrocinnamate of europium, terbium and gadolinium containing 1,10-phenanthroline as ancillary ligand

New binuclear lanthanide (III) complexes of general formula [Ln2(hcin)6(phen)2] (where Ln = Eu 1; Gd 2; Tb 3; hcin = hydrocinnamate anion; phen = 1,10-phenanthroline) were synthesized and fully characterized by elemental analysis, vibrational spectroscopy (infrared and Raman), thermal analysis, CP/MAS 13C NMR and powder X-ray diffraction. Photoluminescence data were obtained from the excitation, emission spectra and luminescence decay curves. The energy transfer process in these complexes were studied in detail.