Partially cyclopentadienyl-substituted tetranuclear lanthanide Schiff base complexes

Treatment of Cp(3)Ln (Ln = Pr, Nd) with an equimolar amount of the Schiff base bis(acetylacetone)ethylenediamine (H(2)acacen) half hydrate (H2L1.1/2H(2)O) or bis(salicylidene)trimethylenediamine (H(2)saltn) half hydrate (H2L2.1/2H(2)O) in THF affords three novel mu -hydroxo-bridged tetranuclear organolanthanide complexes [eta5-CpLn(2)L(2)(mu -OH)](2). nTHF, L = L-1, n = 4, Ln = Pr (1), Nd (2); L = L-2, n = 2, Ln = Nd (3). A reaction scheme was proposed in which the cyclopentadienyl lanthanide coordination motif [CpLnL] (A) and the hydroxyl lanthanide motif [LnL(OH)] (B) cross-reacted and then dimerized through the mu -hydroxo bridges to give the tetranuclear Ln complexes containing an Ln(4)O(8) skeleton with two reciprocally oriented face-sharing defect cubanes. In each monomeric species [CpLn(2)L(2)(OH)] (C) the Ln atoms are 8- or 9-coordinated. All complexes have been characterized by EA, IR and Mass spectroscopy. (C) 2001 Elsevier Science B.V. All rights reserved.