On the basis of 2,6-bisbenzoylactyl pyridine(L1), 2,6-bis[(3-pyrazoleyl) -5-phenyl]pyridine (L2)and2,6-bis[(3-pyrazoleyl)-3,5-bisphenyl]pyridine(L3) are synthesized. With the synthesized organic compounds as organic ligands, corresponding terbium(Ⅲ) complexes are prepared .The composition of these new compounds are confirmed by 1H-NMR, EA , IR spectrum , UV spectrum and MS .The properties of the complexes are characterized by EA,IR spectrum ,UV spectrum,TG-DTA and fluorescence spectra. Photoluminescence measurements indicate that the effective energy transfer from the organic ligand L2 to the central Tb(Ⅲ) ions occurs in the complexe, and strong and characteristic green mission appears due to the 5D4- 7F5 transitions of the 4f electrons of the central Tb(Ⅲ) ions. The fluorescence spectra shows that the fluorescence emission intensity of Tb(L2) 3·3H2O is stronger than that of Tb2(L1) 3·4H2O,but the property of TG-DTA is not so good as we expected. It cannot be the best material for fabrication of organic light-emitting devices.
A new insight into the constant current-constant voltage (CC-CV) charge protocol based on the spherical diffusion model was presented. From the model,the CV-charge process compensates,to a large extent,the capacity loss in the CC process,and the capacity loss increases with increasing the charging rate and decreases with increasing the lithium-ion diffusion coefficient and using a smaller τ value (smaller particle-size and larger diffusion coefficient) and a lower charge rate will be helpful to decreasing the capacity loss. The results show that the CC and the CV charging processes,in some way,are complementary and the capacity loss during the CC charging process due to the large electrochemical polarization can be effectively compensated from the CV charging process.
