RESUMO
The reaction of YbI(2) with KTp(Me2) gives (Tp(Me2))YbI(THF)(2) (1-Yb) as a thermally unstable product. Use of the more hindered KTp(tBu,Me) gave (Tp(tBu,Me))LnI(THF)(n) (Ln = Sm, n = 2, 2-Sm; Ln = Yb, n = 1, 2-Yb). The crystal structures of both these compounds are reported. Adducts with neutral ligands such as pyridines and isonitriles can be prepared and the crystal structures of [(Tp(tBu,Me))YbIL(n)] (L = CN(t)Bu, n = 1; L = 3,5-lutidine, n = 2) are described. 2-Sm can be oxidized using AgBPh(4) to give [(Tp(tBu,Me))SmI(THF)(2)]BPh(4). Compounds 2-Sm and 2-Yb are useful starting materials for the preparation of heteroleptic compounds by metathesis with appropriate potassium reagents. The preparations and characterization of the hydrocarbyls (Tp(tBu,Me))Ln{CH(SiMe(3))(2)} (Ln = Sm, 5-Sm; Yb, 5-Yb) and [(Tp(tBu,Me))Ln{CH(2)(SiMe(3))}(THF)] (Ln = Yb, 6a-Yb) and the triethylborohydrides [(Tp(tBu,Me))Ln(HBEt(3))(THF)(n)] (Ln = Sm, n = 0, 7-Sm; Yb, n = 1, 7-Yb) are reported, as well as the crystal structures of 5-Sm and 5-Yb, and the THF adducts 6a-Yb and [(Tp(tBu,Me))Sm{CH(SiMe(3))(2)}(THF)], 5a-Sm.
RESUMO
Adventitious hydrolysis of a number of different complexes with the molecular formula Ln(Tp(Me2))(2)X [Tp(Me2) = (HB(dmpz)(3)), where X is a basic anionic ligand] in various solvents, yielded crystals of highly insoluble dimers of the general formula [Ln(Tp(Me2))(mu-BOp(Me2))](2) (1) [Ln = La, Ce, Sm; BOp(Me2) = (HBO(dmpz)(2))(2)(-); dmpzH = 3,5-dimethylpyrazole]. The results of several single-crystal X-ray determinations are reported. One metal nitrogen distance, that lying across from the two negatively charged bridging oxygen atoms, is 0.06 A longer than the others, suggesting an unusual trans influence at a lanthanide center. The formation of 1 is proposed to involve the intermediacy of Ln(Tp(Me2))(2)OH formed by protonolysis with adventitious water.
RESUMO
The reaction of lanthanide triflates with 2 equiv of potassium hydrotris(dimethylpyrazolyl)borate (Tp(Me)()2) gives good yields of complexes of composition Ln(Tp(Me)()2)(2)OTf. For La (2), Ce (3), Pr (4), and Nd (5) the complexes are seven-coordinate in the solid state with the triflate group coordinated to the metal in unidentate fashion. Complex 5 crystallizes in the monoclinic space group P2(1)/c with a = 17.629(3) Å, b = 12.740(2) Å, c = 18.163(3) Å, beta = 107.35(1) degrees, V = 3893(1) Å(3), Z = 4, and R(w) = 0.0458. For the complexes of Y (1), Sm (6), Eu (7), Gd (8), Dy (9), Ho (10), and Yb (11), the smaller size of the metal ion leads to ejection of the triflate from the coordination sphere and the complexes are ionic in the solid state with a six-coordinate metal center. Complex 11 crystallizes in the monoclinic space group C2/m with a = 16.593(7) Å, b = 13.671(5) Å, c = 8.746(2) Å, beta = 91.66(3) degrees, V = 1983(1) Å(3), Z = 2, and R(w) = 0.0416. In solution, however, complex 6 adopts a seven-coordinate molecular structure with the triflate ion within the first coordination sphere.
