BINUCLEAR COMPLEXES OF LA(III) AND EU(II) WITH THE BRIDGING NAPHTHALENE DIANION - SYNTHESIS AND X-RAY CRYSTALLOGRAPHIC ANALYSIS OF [MU(2)-ETA(4)ETA(4)-C10H8][LAI2(THF)(3)](2) AND [MU(2)-ETA(4)ETA(4)-C10H8][EUI(DME)(2)](2)

The treatment of LaI3(THF)(3) with equimolar amounts of Li and excess of C10H8 in THF results in the formation of [C18H8][LaI2(THF)(3)](2) (1) and the reaction of EuI2(THF)(2) with Li and C10H8 in DME leads to [C10H8][EuI(DME)(2)](2) (2), which have been characterized by IR and UV-VIS spectroscopy as well as by X-ray crystallography. 1 is monoclinic, space group P2(1)/c (No. 14), Z = 4, with a = 1314.2(6), b = 1256.7(5), c = 1697.2(4) pm, beta = 93.53(3)degrees. The structure was refined to R = 0.045 for 2377 observed reflections (F-o > 4 sigma(F-o)). 2 is monoclinic, space group P2(1)/n, Z= 4, with a = 1015.1(3), b = 1389.8(4), c = 1269.8(3) pm, beta = 97.51(2)degrees. The structure was refined to R = 0.0408 for 2687 observed reflections (F-o > 4 sigma(F-o)). Both molecules contain two LaI2(THF) (1) or EuI(DME) moieties (2), bridged eta(4) each by a non planar naphthalene with dihedral angles of 15 degrees (1) and 6 degrees (2) respectively.