Organometallic compounds of the lanthanides. 134 Synthesis and characterization of the first bisand tris[1-(omega-alken-1-yl)indenyl]lanthanide complexes

1-Allyl-2,4,7-trimethyl-1 H-indene (1) and 1-(3-buten-1-yl)-4,7-dimethyl-1 H-indene (2), which are to prepare from (2,4,7-trimethylindenyl)lithium and allyl chloride or from (4,7-dimethylindenyl)lithium and 4-bromo-1-butene, react with n-butyllithium yielding (1-allyl-2,4,7-trimethylindenyl)lithium [LiL (1a)] or [1-(3-buten-1-yl)-4,7-dimethyl indenyl]lithium [LiL' (2a)], r espectively. The reactions of the trichlorides of gadolinium, erbium, yttri um, lutetium, and ytterbium with la or 2a (mole ratio 1:2) in THF produce t he bis(indenyl)lanthanide chloride complexes L(2)LnCl(THF) [Ln = Gd (1b), E r (1c)], L-2'LnCl(THF) [Y (2d), Lu (2e)], or L-2'Yb(mu-Cl)(2)Li(THF)(2) (2f ), whereas the trichlorides of the comparatively large samarium and lanthan um ions react with different molar amounts of 2a in TMF exclusively with fo rmation of the tris(indenyl) complexes L-3'Sm (2g) or L-3'La(mu-Cl)Li(Et2O) (3) (2h), respectively. All new compounds were characterized by elemental a nalyses, mass spectrometry and the diamagnetic compounds 2d, 2e and 2h also by H-1 and C-13{H-1}-NMR spectroscopy. The single crystal X-ray structural analyses of 1 c, 2 f, 2 g and 2 h demonstrate that the alkenyl groups of t he indenyl side chains are not coordinated to the lanthanide atoms.