Heteroleptic polypyrazolylborate complexes of the lanthanides: Syntheses and molecular structures of [Nd{HB(pz)(3)}(2)Cl(H2O)] (HB(pz)(3)=hydrotris(pyrazol-1-yl)borate) and [Nd{HB(pz*)(3)}LCl2] (HB(pz*)(3)=hydrotris(3,5-dimethylpyrazol-1-yl)borate; L=4,4'-di-tert-butyl-2,2'-bipyridine)

The new heteroleptic hydrotris(pyrazol-1-yl)borate lanthanide complex [Nd{HB(pz)(3)}(2)Cl] (1) was prepared from the reaction between anhydrous NdCl3 and 2 equiv. of K[HB(pz)(3)] in THF at room temperature. The H2O adduct of 1, [Nd{HB(pz)(3)}(2)Cl(H2O)]. THF (2), is formed when a solution of 1 is allowed to stand al room temperature in the presence of moisture. Reaction of K[HB(pz*)(3)] with anhydrous NdCl3 in the presence of 4,4'-di-tert-butyl-2,2'-bipyridine (L) yields [Nd{HB(Pz*)(3)}LCl2] (3) in moderate yield. All complexes have been characterized by conventional spectroscopic methods. The molecular structures of 2 and 3 have been determined by X-ray crystallography.