Sntheses and structures of mononuclear eight-coordinate Na[ErIII(Cydta)(H2O)2]•5H2O (Cydta = trans-1,2-cyclohexanediaminetetrqacetic acid and binuclar nine-coordinate Na2[SmIII(Cydta)][SmIII(Cydta)(H2O)3]•11H2O

The title complexes, Na[Er-III(Cydta)(H2O)(2)]center dot 5H(2)O (1) and Na-2[Sm-III(Cydta)][Sm-III(Cydta)(H2O)(3)]. 11H(2)O (H) (Cydta is trans-1,2-cyclohexanediaminetetraacetic acid), are prepared and characterized using IR, elemental analyses, and single-crystal X-ray diffraction techniques. Crystal I belongs to triclinic system (space group P1), which has a mononuclear eight-coordinate slightly distorted square antiprismatic conformation. The crystal data are as follows: a = 8.371(12) A, b = 9.952(14) A, c = 14.74(2) A, alpha = 88.32(2)degrees, beta = 76.30(2)degrees, gamma = 87.87(2)degrees, V = 1192(3) A(3), Z = 1, rho = 1.835 g/cm(3), L = 3.612 mm(-1), F(OOO) = 658, R = 0.0194, and wR = 0.0520 for 4130 observed reflections with I >= 2 sigma(I). Crystal II belongs to monoclinic system (space group P2(1)/n), which has the binuclear nine-coordinate structure with tricapped trigonal prismatic conformation for Sm(l) and the pseudomonocapped square antiprismatic conformation for Sm(2). The crystal data are as follows: a = 12.283(6) A, b = 15.626(7) A, c = 25.875(12) A, beta = 97.962(7)degrees, V = 4919(4) A(3), Z = 4, rho = 1.717 g/cm(3), mu = 2.476 min(-1), F(000) = 2536, R = 0.0781, and wR = 0.1745 for 8554 observed reflections with I >= 2 sigma(I).