Heterobimetallic Three-Dimensional 4D-4F Coordination Polymers Based on 5-Methyl-1-(pyridyn-4-ylmethyl)-1h-1,2,3-triazole-3,4-dicarboxyla Te

Three novel 4f-4d heterometallic coordination polymers (CPs), [Ln(H2O)(3)CdL2(NO3)].6H(2)O (L = ethyl 5-methyl1-(pyridin-4-ylmethyl)-1H-1,2,3-triazole-3,4-dicarboxylate; Ln = Eu, Gd, Tb 1, 2 and 3, respectively) have been successfully synthesized by hydrothermal treatment and slow cooling-down crystallization. These CPs have been structurally characterized by single-crystal X-ray diffraction. 1-3 are isostructural and consist of a three-dimensional network showing channels. The networks are reinforced via hydrogen bonds and pi-pi stacking interactions. The crystal topology analysis shows an infinite 2D layer topology with net symbol {4,4} (sql). The magnetic behavior of these compounds is explained by the expected contribution of almost isolated Ln (III) ions. An energy gap of 375 cm(-1) between the F-7(0) ground state and the first excited state of compound 1 has been deduced from magnetic data showing an excellent agreement with the spectroscopic data.