Stabilization of Lithium Borohydride with Nitrogen Donor, Chelating Ligands. Syntheses and Solid State Structures of [HC(3,5-Me 2 pz) 3 ]Li(η 3 -BH 4 ), {[H 2 C(3,5-Me 2 pz) 2 ]Li(μ-η 3 -BH 4 )} 2 , and {[4,4‘-Me 2 bipy]Li(μ-η 3 -BH 4 )} 2 (pz = pyrazolyl, bipy = bipyridyl)
1997; American Chemical Society; Volume: 36; Issue: 27 Linguagem: Inglês
10.1021/ic970815h
ISSN1520-510X
AutoresDaniel L. Reger, J. E. Collins, Michael A. Matthews, Arnold L. Rheingold, Louise M. Liable‐Sands, Ilia A. Guzei,
Tópico(s)Radioactive element chemistry and processing
ResumoThe reaction of HC(3,5-Me2pz)3 and LiBH4 in THF yields [HC(3,5-Me2pz)3]Li(η3-BH4) (pz = pyrazolyl). In the solid state, the borohydride ligand is tridentate with an octahedral arrangement about the lithium. A similar reaction using HC(pz)3 yields the insoluble ionic compound {[HC(pz)3]2Li}(BH4). Reaction of equimolar amounts of LiBH4 and H2C(3,5-Me2pz)2 yields {[H2C(3,5-Me2pz)2]Li(μ-η3-BH4)}2. This complex is a centrosymmetric dimer in the solid state having two bridging [η3-BH4]- ligands. For each [η3-BH4]- ligand, there is one μ3-H and two μ2-H atoms. A similar reaction with H2C(pz)2 yields {[H2C(pz)2]Li(BH4)}2 and with 4,4‘-dimethyl-2,2‘-bipyridine (4,4‘-Me2bipy) yields {[4,4‘-Me2bipy]Li(μ-η3-BH4)}2. The structure of {[4,4‘-Me2bipy]Li(μ-η3-BH4)}2 in the solid state is similar to that of {[H2C(3,5-Me2pz)2]Li(μ-η3-BH4)}2, except the Li2B2 central core is not planar and both μ3-H atoms are on the same side of this core.
Referência(s)