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摘要
In acidic solution, a serials of water-soluble coordination polymers (CPs) were isolated as zonal 1D-CPs 1,3-propanediaminetetraacetato lanthanides [Ln(1,3-H(3)pdta)(H2O)(5)](n)center dot 2Cl(n)center dot 3nH(2)O [Ln=La, 1; Ce, 2; Pr, 3; Nd, 4; Sm, 5] (1,3-H(4)pdta=1,3-propanediaminetetraacetic acid, C11H18N2O8) in high yields. When 1 eq. mol potassium hydroxide was added to the solutions of 1D-CP5, respectively, two 1D-CPs[Ln(1,3-H(2)pdta)(H2O)(3)](n)center dot Cl-n center dot 2nH(2)O[Ln=Sm, 6; Gd, 7] were isolated at room temperature and seven 2D-CP5 [Ln (1,3-H(2)pdta)(H2O)(3)](n)center dot Cl-n center dot H2O [Ln=La, 8; Ce, 9; Pr, 10; Nd, 11; Sm, 12; Eu, 13; Gd, 141 were isolated at 70 degrees C. When the crystals of 1-4 were hydrothermally heated at 180 degrees C with 1-2 eq. mol potassium hydroxide, four 3D-CPs [Ln(1,3-Hpdta)](n)center dot nH(2)O [Ln=La, 15; Ce, 16; Pr, 17; Nd, 181 were obtained. The two 2D-CPs [Ln(1,3-Hpdta)(H2O)](n)center dot 4nH(2)O (Sm, 19; Eu, 20) were isolated in similar reaction conditions. With the increments of pH value in the solution and reaction temperature, the structure becomes more complicated. 1-5 are soluble in water and 1 was traced by solution C-13{H-1} NMR technique, the water-soluble lanthanides 1 and 5 show catalytic activity to ester hydrolysis reaction respectively, which indicate their important roles in the hydrolytic reaction. The europium complexes 13 and 20 show visible fluorescence at an excitation of 394 nm. The structure diversity is mainly caused by the variation of coordinated ligand in different pH values and lanthanide contraction effect. Acidic conditions are favorable for the isolations of lanthanide complexes in different structures and this may helpful to separate different lanthanides. The thermal stability investigations reveal that acidic condition is favorable to obtain the oxides at a lower temperature.
- 出版日期2014-11
- 单位厦门大学
