Main Group Pyrazolates—the X-Ray Structures of [Al(η2-But2pz)3], [SnMe3(η1-Ph2pz)] and [GePh3(η1-But2pz)] (R2pz = 3,5-Disubstituted Pyrazolate)

Abstract

From metathesis reactions between AlCl₃, SnMe₃Cl, or GePh3Br and the appropriate potassium 3,5-disubstituted pyrazolate [K(R₂pz)] the complexes [Al(Bu ^t ₂pz)₃], [SnMe₃(Ph₂pz)], [SnMe₃(Bu ^t ₂pz)], and [GePh₃(Bu ^t ₂pz)] have been obtained. The X-ray structure of [Al(Bu ^t ₂pz)₃] shows the complex to be monomeric with η² -pyrazolate groups, in a quasi-trigonal prismatic array: the first monomeric homoleptic tris(pyrazolato) complex of any element. X-Ray structures of [SnMe₃(Ph₂pz)] and [GePh₃(Bu ^t ₂pz)] reveal mononuclear species with distorted tetrahedral stereochemistries and η¹ -pyrazolate groups. Comparisons of spectroscopic data between [SnMe₃(Ph₂pz)] and [SnMe₃(Bu ^t ₂pz)] suggest the latter is also four-coordinate with an η¹ -Bu ^t ₂pz ligand.