PRIMARY TO SECONDARY SPHERE COORDINATION OF 15-CROWN-5 TO LANTHANIDE(III) CHLORIDES - STRUCTURAL-ANALYSIS OF [MCL(3)(15-CROWN-5)] (M=LA, CE) AND [ER(OH2)8]CL-3-CENTER-DOT-15-CROWN-5

Complexes of LaCl3.7H(2)O and CeCl3.7H(2)O directly coordinated to 15-crown-5 were prepared by placing the reactants in 3:1 CH3CN:CH3OH on opposite sides of a fine porosity glass frit in a U-shaped cell and passing a 10 mu A current through the cell. The crystal structures of the two anhydrous 8-coordinate complexes, [MCl(3)(15-crown-5)] (M = La, Ce) have been determined. Each contains the lanthanide in a bicapped trigonal prismatic geometry. The two complexes are isostructural crystallizing in the monoclinic space group P2(1)/c with (at 20 degrees C) for M = La: a = 8.217(8), b = 14.298(2), c = 14.341(9)Angstrom, beta = 104.79(8)degrees, and D-calc = 1.90 g cm(-3) for Z = 4; for M = Ce: a = 8.208(9), b = 14.263(6), c = 14.270(8)Angstrom, beta = 104.74(7)degrees, and D-calc = 1.92 g cm(-3) for Z = 4. Direct reaction of ErCl3.6H(2)O with 15-crown-5 in 3:1 CH3CN:CH3OH resulted in the crystallization of the second sphere hydrogen bonded complex [Er(OH2)(8)]Cl-3.15-crown-5. This complex is monoclinic, P2(1)/n with (at 18 degrees C) a = 9.193(3), b = 17.235(9), c = 15.216(5)Angstrom, beta = 92.48(3)degrees, and D-calc = 1.76 g cm(-3) for Z = 4. The Er3+ ion is dodecahedral.