Syntheses and crystal structures of four-coordinate aryloxo neodymium complexes

Two four-coordinate complexes of neodymium with 2,6-di-tert-butyl-4-methylphenolate have been synthesized and their single-crystal structures determined. Anhydrous NdCl3 reacted with ArONa in a 1:3 molar ratio in THF at room temperature to yield the neutral four-coordinate complex [(ArO)(3)Nd(THF)]. MePh (1), which crystallized as a solvate. in which three aryloxide ligands and one THF ligand are coordinated to neodymium to form a slightly distorted tetrahedron. The reaction of NdCl3, with 4 equiv. of ArONa in THF gave [(ArO)(4)Nd][Na(THF)(6)] (2). In this anion-cation pair compound, the neodymium and sodium atoms exhibit distorted tetrahedral and distorted octahedral coordination geometry, respectively. The average Nd-O(Ar) distance is 2.176 and 2.230 Angstrom in complex 1 and 2, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.