Synthesis, structure, and reactivity of organometallic complexes of samarium: (C(8)H(8))2-, (C(5)Me(5))-, and [N(SiMe(3))(2)]- ligand systems

This dissertation describes the expansion of the remarkable chemistry of the strongly reducing Sm(II) ion in organometallic complexes. The organometallic chemistry of Sm(III) has also been advanced by exploring the reactivity of the sterically crowded (C₅Me₅)₃Sm.; In the first part of the dissertation, new Sm(II) cyclooctatetraenyl chemistry is described. The research described here shows that, by sharing the cyclooctatetraenyl ligand between two Sm(II) centers, arene and alkane soluble complexes can be synthesized which provide new types of Sm(II) reduction chemistry.; Six new Sm(II) cyclooctatetraenyl complexes were sythesized including: K[(C₅Me₅)Sm(C₈H₈)](THF)_n , 1, [(C₅Me₄R)Sm(THF)]₂(μ-η 8:η8-C₈H₈) (R = Me, 2; Et, 3), [(C₅Me₅)Sm(diglyme)] ₂(μ-η8:η8-C₈H ₈), 4, and [(C₅Me₄R)Sm]₂(μ-η 8:η8-C₈H₈) (R = Me, 5; Et, 6). Surprisingly, the unsolvated 5 and 6 are bent.; Complexes 2, 3, 5 and 6 react with C₈H₈ to form complexes of the type (C₅Me₄R)Sm(C₈H₈)(THF)_n. Complex 2 reacts with C₅Me₅Cl to form (C ₅Me₅)Sm(C₈H₈)(THF) and (C₅Me ₅)₂SmCl(THF). (C₅Me₅)Sm(C₈H ₈),7, was also found to be bent.; Another new example of a bimetallic Sm(II) compound was synthesized utilizing [N(SiMe₃)₂]− to replace (C ₅Me₅)−. The Sm(II) inverse sandwich {lcub}[(Me₃Si)₂N]Sm(THF)₂{rcub}₂(μ-η 8:η8-C₈H₈), 8, has a structure similar to that of 4 in that a cyclooctatetraenyl ligand is sandwiched between two solvated Sm(II) centers capped with solubilizing ligands.; In the second part of the dissertation, the reactivity of (C₅Me ₅)₃Sm is described.; (C₅Me₅)₃Sm was found to behave as a bulky alkyl with CO₂ to quantitatively form (C₅Me ₅)₂Sm(O₂CC₅Me₅), 9, a carboxylate in which CO₂ has apparently inserted into a Sm-(η1-C₅Me₅) bond.; The reaction of (C₅Me₅)₃Sm with SePPh ₃ was studied in detail; this reaction can be tuned to form either the previously characterized Se2-compound [(C₅Me ₅)Sm(THF)]₂(μ-Se), 10, or the (Se₂) 2− compound [(C₅Me₅)Sm]₂(μ-Se ₂), 11, by varying the stoichiometry or reaction conditions.; The impact of the studies in expanding the range of known organometallic compounds of samarium as well as the insight provided into their synthesis, reactivity and structure are discussed.