Abstract: Lanthanocene chlorides (C₄H₇OCH₂C₉H₆)₂ LnCl[Ln=Y(1); Ln=Gd(2)] were synthesized by the reaction of tetrahydrofurfurylindenyl lithium(in situ) with corresponding anhydrous lanthanide chorides in THF. The crystal structures of these two complexes were determined by X-ray diffraction and they were unsolvated monomeric complexes. They were stable in the air for several hours. Complexes 1 and 2 belong to the same crystal system(orthorhombic) and space group(P2₁2₁2₁). The unit cell dimensions of complex 1 were a=1.042 52(9) nm, b=1.474 55(12) nm, c=1.497 99(13) nm, Z=4, D c=1.508g/cm³; The unit cell dimensions of complex 2 were a=1.037 01(10) nm, b= 1.472 33(12) nm, c=1.513 54(14) nm, Z=4, D c=1.699 g/cm³. They have the same structure and different space configurations. The central metal atom is coordinated by two indenyl, two oxygen of the tetrahydrofurfuryl and one chlorine atom to form a distorted trigonal bipyramid.

Key words: Tetrahydrofurfurylindenyl, Rare earth complex, Crystal structure, Synthesis