Poly(pyrazolyl)borate Complexes of Tin(II) and Lead(II). The Quest for a Coordination Complex with a Stereochemically Inactive Lone Pair

All articles of this category The complexes [H n B(pz) 4-n ] m SnCl 2-m (n = 0, 1 and 2; m = 1 and 2; pz = pyrazolyl ring), [H n B(pz) 4-n ] 2 Pb and [HB (3,5-Me 2 pz) 3 ] 2 Pb have been prepared and structurally characterized. Both [B(pz) 4 ] 2 Sn and [B(pz) 4 ] 2 Pb are only four cooridnate, whereas [HB(pz) 3 ] 2 Pb is six coordinate. In all three structures the lone pair on the metal is stereochemically active. The complex [HB(3,5-Me 2 pz) 3 ] 2 Pb is six coordinate, and the geometry about the lead atom is a trigonally distorted octahedron. It is the first six-coordinate, main-group, molecular complex in which the lone pair is stereochemically inactive. 1. Introduction 2.Tin(II) Chemistry 2.1. Variable Temperature 1 H NMR 2.2. 119 Sn NMR Data 3. Lead(II) Chemistry 3.1. Variable Temperature 1 H NMR 4. Conclusions