Unusual photoluminescence properties of the 3D mixed-lanthanide-organic frameworks induced by dimeric structures: a theoretical and experimental approach.

The present work describes a complementary experimental and theoretical investigation of the spectroscopic properties of the four isostructural 3D Ln-MOFs (wherein PDC = pyrazole-3,5-dicarboxylate, [La2(PDC)3(H2O)4]·2H2O (1), [(La0.9Eu0.1)2(PDC)3(H2O)4]·2H2O (2), [(La0.9Tb0.1)2(PDC)3(H2O)4]·2H2O (3) and [(La0.9Eu0.5Tb0.5)2(PDC)3(H2O)4]·2H2O (4)). The experimental data and theoretical calculations show that the singular photophysical properties presented by these Ln-MOFs are induced by strong interaction between the Ln(3+) ions.