Structural characterization and reactivity studies of the samarium aryloxide complex Sm(O-2,6-Pr2iC6H3)(3)(THF)(2)

Reaction of the samarium aryloxide bis-THF adduct Sm(OAr)(3)(THF)(2) (1; Ar = 2,6-(Pr2C6H3)-C-i) with two equivalents of pyridine produces the bis-pyridine complex Sm(OAr)(3)py(2) (2) in 85% yield. Compound 1 also reacts with an excess of pyridine to form the tris-pyridine adduct Sm(OAr)(3)py(3) (3) in excellent yield. Addition of one equivalent of KOAr to 1 leads to the isolation of the potassium salt K[Sm(OAr)(4)] (4) in high yield. The salt 4 reacts with one equivalent of pyridine to form the mono-pyridine adduct K[Sm(OAr)(4)py] (5). Compounds 1-5 have been characterized by H-1 NMR and IR spectroscopy, elemental analysis and, in the case of 1, by a single-crystal X-ray diffraction study. In the solid state, 1 adopts a trigonal bipyramidal structure in which THF ligands occupy axial sites. Sm-O distances to the aryloxide ligands average 2.14(2) Angstrom, while those to THF ligands average 2.45(2) Angstrom.