SYNTHESIS AND CRYSTAL-STRUCTURE OF BINUCLEAR DIINDENYLLANTHANIDE ALKOXIDES, X-RAY CRYSTAL-STRUCTURE OF [(C9H7)(2)ND(MU,ETA(2)-OCH2CHCH2CH2CH2)](2)

The reaction of triindenyllanthanide complexes (C9H7)(3)Ln . THF (Ln = Nd, Pr) with equimolar 2-tetrahydrofurfuryl methanol in THF solution at room temperature forms two new binuclear diindenyllanthanide alkoxi des, namely [GRAPHICS] [Ln = Nd (1) arid Pr (2)]. These two new comple xes have been characterized by IR, MS spectra and metal analysis, indi cating they are oxygen- bridging dimers. Complex 1 has also been studi ed by X-ray crystallography. The crystal structure of Nd complex revea led that the oxygen atoms of tetrahydrofurfuryl methoxide ligand act a s both a bridging and a chelate donating group in the title complexes. The Nd atom is coordinated by two eta(5)-C9H7 ring centroids, two oxy gen atoms of tetrahydrofurfuryl methoxide ligands and an oxygen atom o f tetrahydrofuran ring, indicating a nine coordination number. The Nd- C(eta(5)-C9H7) distances range from 2.79(2) to 2.92(2) Angstrom, avera ging 2.81(2) Angstrom. The Nd-O(1)(mu-OR') bond distances are 2.30(1) and 2.31(1) Angstrom, averaging 2.305(1) Angstrom. In the intramolecul ar five-membered chelating ring, the Nd-O(2) distance is 2.51(1) Angst rom. (C) 1997 Elsevier Science Ltd.