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. 相似文献
In this study, tetradecanol–palmitic acid/expanded perlite composites containing carbon fiber (TD-PA/EP-CF CPCMs) were prepared by a vacuum impregnation method. Binary eutectic mixtures of PA and TD were utilized as thermal energy storage material in the composites, where EP behaved as supporting material. X-ray diffraction demonstrated that crystal structures of PA, TD, EP, and CF remained unchanged, confirming no chemical interactions among raw materials besides physical combinations. The microstructures indicated that TD-PA was sufficiently absorbed into EP porous structure, forming no leakage even in molten state. Differential scanning calorimetry estimated the melting temperature of TD-PA/EP-CF CPCM to 33.6 °C, with high phase change latent heat (PCLH) of 138.3 kJ kg−1. Also, the freezing temperature was estimated at 29.7 °C, with PCLH of 137.5 kJ kg−1. The thermal cycling measurements showed that PCM composite had adequate stability even after 200 melting/freezing cycles. Moreover, the thermal conductivity enhanced from 0.48 to 1.081 W m−1 K−1 in the presence of CF. Overall, the proposed CPCMs look promising materials for future applications due to their appropriate phase change temperature, elevated PCLH, and better thermal stability.
