Control of the stereochemical impact of the lone pair in lead(II) tris(pyrazolyl)methane complexes. Improved preparation of Na[B[3,5-(CF3)2C6H3]4].

摘要: The reaction of Pb(acac)2 with 2 equiv [H(Et2O)2]{B[3,5-(CF3)2C6H3]4} (HBArf) in CH2Cl2 followed by addition either HC(pz)3 or HC(3,5-Me2pz)3 (pz = pyrazolyl ring) leads to the formation {Pb[HC(pz)3]2}{B[3,5-(CF3)2C6H3]4}2 (1) and {Pb[HC(3,5-Me2pz)3]2}{B[3,5-(CF3)2C6H3]4}2 (2), respectively. cation 1 has a distorted octahedral structure stereochemically active lone pair on lead(II). In contrast, is trigonally lead(II) clearly inactive. driving force for this have inactive that geometric arrangement interligand distances between adjacent 3-position methyl groups are close 4.0 A, sum van der Waals radii two groups. To facilitate chemistry, synthesis Na{B[3,5-(CF3)2C6H3]4}, needed prepare HBArf, been dramatically improved. main change add NaBF4 mixture before forming ...