Synthesis and fluorescence properties of ten lanthanide benzene-1,3,5-tricarboxylate complexes

Ten new lanthanide benzene-1,3,5-tricarboxylate complexes Tb(btc)·6H2O (1), nano-scale Tb(btc)·6H2O (2), Tb2(btc)2(phen)3·4H2O (3), TbLn(Hbtc)2(phen)2 Cl2·H2O [Ln = Y(4), and Gd (5), btc = benzene-1,3,5-tricarboxy-late], TbLa(btc)2(phen)3·6H2O (6) and TbM(btc)(C2H5OH)2Cl2·2H2O [M = Zn (7), Cd (8), Mn (9) and Ni (10)] have been synthesized and characterized. The fluorescence intensity of nano-scale complex (2) is stronger than that of the complex (1), indicating that there are new and special fluorescence properties in nano-scale complex due to the nano-scale effect and quenching by the proximity of surface defects. The fluorescence intensity of the ternary complex (3) is stronger than that of the binary complex (1). The studies of the fluorescence spectra and lifetimes of the other seven complexes show obviously different results. The luminescent intensity of the complexes (4), (5), (6), (7) and (8), which contain the metal ions Y3+, La3+,Gd3+, Zn2+ and Cd2+, increased remarkably. Complexes (9) and (10), containing Mn2+ and Ni2+, respectively, exhibit fluorescence quenching, which is caused by the unsaturated d-layer electrons consuming the energy in the form of radiative transition.