NH3 and (NH2)1− as ligands in yttrium metallocene chemistry

Abstract

(C₅Me₅)₂Y(C₃H₅)(THF) reacts with ammonia in THF to form the first crystallographically-characterized rare-earth metal complex with a terminal (NH₂)¹⁻ ligand, (C₅Me₅)₂Y(NH₂)(THF), 1. Complex 1 can be protonated with [HNEt₃][BPh₄] to form [(C₅Me₅)₂Y(NH₃)(THF)][BPh₄], 2. Both complexes were characterized by X-ray crystallography which allowed a comparison of the Y–NH₂ bond length, 2.226(2) Å, with an Y–NH₃ bond length, 2.476(2) Å, in analogous coordination environments. Reactions of 2 with NaN₃ and acetone produced the known complexes [(C₅Me₅)₂YN₃]_x and [(C₅Me₅)₂Y(OCMe₂)₂][BPh₄], respectively, suggesting that the ammonia moiety in 2 functions as a displaceable solvate like THF.