A series of novel metal-ferrocenedicarboxylate coordination polymers: crystal structures, magnetic and luminescence properties

Novel two-dimensional layered lanthanide(III)-ferrocenedicarboxylate coordination polymers {[M(η2-O2CFcCO2-η2)(μ2-η2-O2CFcCO2-η2-μ2)0.5(H2O)2]·mH2O}n (Fc=(η5-C5H4)Fe(η5-C5H4), M=Tb3+, m=2, 1; M=Eu3+, m=2, 2; M=Y3+, m=1, 3) with trapezium-shaped units and one-dimensional wave-shaped Cd(II)-ferrocenedicarboxylate polymer {[Cd(η2-O2CFcCO2-η2)(H2O)3]·4H2O}n (4) have been prepared and structurally characterized by single crystal diffraction. In polymers 1–3, each central metal ion (Tb(III), or Eu(III) or Y(III)) is located in a pseudo-capped-tetragonal prism coordination geometry, and ferrocenedicarboxylate anion ligands have two coordination modes (bidentate-chelating mode and tridentate-bridging mode). The magnetic behaviors for 1 and 2 are studied in the temperature range of 5.0–300 K. The results show that the paramagnetic behavior of 2 is mainly due to the effective spin–orbital coupling between the ground and excited states through the Zeeman perturbation, and the weak magnetic interaction between Eu3+ centers can be observed. In addition, compared with sodium ferrocenedicarboxylate, the fluorescent intensities of the polymers 1–4 are enhanced in the solid state.