ORGANOMETALLIC COMPOUNDS OF THE LANTHANIDES .102. SYNTHESIS AND CHARACTERIZATION OF EU(II) AND SM(II) COMPLEXES CONTAINING THE CYCLOPENTADIENYLVANADIUMNAPHTHALENE ANION - MOLECULAR-STRUCTURE OF [(C5H5)V(C10H8)](2)EU(THF)(DME) AND [(C5H5)V(C10H8)EU(C5H5)(THF)](N)

The reaction of LnI(2)(DME)(3) with an equimolar mixture of K(C5H5) an d K(C5H5)V(C10H8) in DME followed by treatment with THF results in the formation of the tetradecker bimetallic complexes ([C5H5)V(C10H8)](2) Ln(THF)(DME) with Ln = Eu (1) and Sm (2). Removal of the solvent and s ubsequent addition of THF leads to coordination polymers [(C5H5)V(C10H 8)Ln(C5H5)(THF)](n) with Ln = Eu (3) and Sm (4). These novel complexes have been characterized by IR spectroscopy and the europium derivativ es by X-ray crystallography. 1 is triclinic, space group P1 (No. 2), Z = 2, with a = 1203.6(4), b = 1230.8(6), c = 1140.8(3) pm, alpha = 91. 37(4), beta = 97.14(3), gamma = 100.44(3)degrees. The structure was re fined to R = 0.026 for 3027 observed reflections (F-o > 3 sigma(F-o)). It shows two (C5H5)Eu(C10H8) sandwich units eta(6)-bonded to Eu via o ne six membered ring of the naphthalene with an additional THF and DME coordinated to europium. 3 is monoclinic, space group C2/c (No. 15), Z = 8, with a = 1916.0(3), b = 1330.4(3), c = 1765.3(4) pm, and beta = 90.17(2)degrees. The structure was refined to R = 0.032 for 2734 obse rved reflections (F-o > 4 sigma(F-o)). It forms infinite polymeric zig -zag chains consisting of (C5H5)Eu units, in which the europium atoms are coordinated by an additional THF and (C5H5)V(C10H8) units which ar e each bonded eta(2) via a naphthalene.