Preparation and Reactivity of a Compartmental Schiff-Base Samarium Dinuclear Complex Tiffany Dube ´, † Sandro Gambarotta,* ,† and Glenn Yap ‡ Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada, and X-ray Laboratory, Faculty of Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada Received April 29, 1998 SmI 2 (THF) 5 acted as a reducing agent in the reaction with phenylenebis(3,5-Bu t 4 - salicylidene)iminatosodium, (3,5-Bu t 4 salophen)Na 2 (THF) 2 , to yield a dimeric compound [Sm 2 - (SB-SB)(THF) 3 ]‚2toluene (2) [SB-SB ) C-C bonded 3,5-Bu t 4 salophen dimer] arising from the reductive C-C coupling of two imine functional groups of two 3,5-Bu t 4 salophenSm units. Complex 2 reacts with MeLi, resulting in a novel oxo-bridged dimer, {[(Me 2 -SB)Sm(µ- CH 3 )Li(THF)][(Me 2 -SB)Sm(µ-CH 3 )Li(THF) 2 Li(THF) 2 ]}(µ-O)(µ-Li) 3 (3) [Me 2 SB ) phenyl- enebis(3,5-Bu t 4 salycyl)dimethyldiamidato], featuring alkylation of both Sm atoms and arising from cleavage of the C-C bond connecting the two units, as well as complete reduction of the imine groups of the two salophen ligands and THF deoxygenation. Similar cleavage of the connecting C-C bond of complex 2 was also observed during the reaction with dry O 2 to form a distorted cuboid cluster in which four Sm atoms are bridged by four hydroxyl groups, [(3,5-Bu t 4 salophen)Sm(OH)] 4 ‚4toluene (4). The structures of complexes 2, 3, and 4 were elucidated by X-ray crystallography. Introduction Throughout the last two decades, the chemistry of lanthanides has developed from a minor field into an important area of organometallic chemistry. 1 This activity is a result of the growing awareness of the unique and interesting chemical properties specific to these elements. In view of the radial extension and ionic character of the lanthanides, cyclopentadienyl ligands have been particularly versatile for the stabi- lization of organolanthanide derivatives because they meet the electronic and steric requirements necessary to form thermally stable, isolable complexes. For Sm- (II), the most powerful reductant of the three lan- thanides which exist in the +2 oxidation state, 2 the C 5 Me 5 ligand has been especially efficient in providing soluble complexes. To date, permethylated cyclopenta- dienyl anions have allowed for the isolation of some of the most highly reactive organolanthanide derivatives providing new classes of complexes 3 exhibiting remark- able structures 4 and unique reactivities. 5 Given the caliber of the transformations and the number of structurally characterizable, metal-containing products afforded by the (C 5 Me 5 ) 2 Sm(THF) 2 system with a variety of substrates, the scope of Sm(II) chemistry has widened in order to accommodate other ligands. Nonetheless, examples of well-defined, non-Cp-containing Sm(II) systems remain relatively few, except for a handful of examples of divalent samarium complexes with phos- phorus, 6 nitrogen, 7 and oxygen-based 8 ligand systems. † Department of Chemistry. ‡ X-ray Laboratory. (1) (a) Evans, W. J.; Hozbor, M. A. J. Organomet. Chem. 1987, 326, 299, and references cited therein. (b) Schaverien, C. J. Adv. Organomet. Chem. 1994, 36, 283, and references cited therein. (c) Marks, T. 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