Studies on organolanthanoid complexes LI. Syntheses of bis- and tris(2-methoxyethylcyclopentadienyl) lanthanoid complexes and crystal structures of bis(2-methoxyethylcyclopentadienyl)ytterbium iodide and tris(2-methoxyethylcyclopentadienyl)samarium

Article abstract of DOI:10.1016/0022-328X(93)80459-O

Reactions of lanthanoid triiodides (Ln = Sm, Yb) with two or three equivalents of 2-methoxyethylcyclopentadienyl potassium salt in tetrahydrofuran afford bis(2-methoxyethylcyclopentadienyl) lanthanoid iodide complex Cp'2YbI (I) (Cp' = MeOCH2CH2C5H4), tris(2-methoxyethylcyclopentadienyl) lanthanoid complexes Cp'3Sm (II) and Cp'3Yb (III), respectively.The compound Cp'2YbI (I) crystallizes from THF/hexane in orthorhombic space group P2₁2₁2₁ with cell dimensions a = 10.892(2), b = 12.278(3), c = 12.805(5) Angstroem, V = 1712.4 Angstroem³, D_calcd = 2.118 g cm^-3for Z = 4.The central metal Yb is coordinated by two Cp' ring centroids, one iodine atom and two oxygen atoms of Cp' forming a distorted trigonal bipyramid.The crystal of Cp'3Sm (II) belongs to the monoclinic crystal system, space group P2₁/n with a = 8.415(7), b = 20.439(3), c = 12.926(2) Angstroem, β = 90.34(3) deg, V = 2223.2 Angstroem³, D_calcd = 1.562 g cm^-3 and Z = 4.The three Cp' ring centroids and two oxygen atoms of Cp' describe a trigonal bipyramid around the central ion of samarium.Complexes I, II and III are all unsolvated monomeric molecules with higher coordination number.