Structural characterization of tris(pyrazolyl)hydroborato and tris(2-pyridylthio)methyl lithium compounds: Lithium in uncommon trigonal pyramidal and trigonal monopyramidal coordination environments ☆

摘要: Abstract X-ray diffraction reveals that the molecular structures of tris(pyrazolyl)hydroborato and tris(2-pyridylthio)methyl lithium compounds, [ Tp Bu t ,R ]Li (R = H, Me) [κ4-Tptm]Li, respectively exhibit three-coordinate trigonal pyramidal four-coordinate monopyramidal coordination geometries, both which are uncommon for lithium. Accordingly, ,Me bind additional ligands to form adducts, such as ]Li(NCMe), ]Li( pz H ), ) · ( ]Li(OH2), ]Li(OH2)·(pzH) ]Li(OH2)·(THF), each has been structurally characterized by in solid state. In solution, however, dissociation ligand (L) from adducts ]LiL is facile exist equilibrium with L, demonstrated NMR spectroscopic studies.