Organoamido- and Aryloxo-lanthanoids. III. Preparation and X-Ray Structure of Bis(μ-3,5-dimethylpyrazolato-N:N′)bis(μ-tetrahydrofuran-O)-bis[bis(η²-3,5-dimethylpyrazolato-N,N')neodymium(III)]

Abstract

Reaction of neodymium metal with bis ( pentafluorophenyl )mercury and pyrazole ( Hpz ) or 3,5-dimethylpyrazole ( Hdmpz ) in tetrahydrofuran ( thf ) yields Nd ( pz )₃ or [ Nd ( dmpz )₃( thf )]₂. X-Ray crystallography has shown that [Nd (dmpz )₃( thf )]₂ [triclinic, space group Pī (No. 2), a 11.070(4), b 11.364(3), c 10.867(2)Ǻ, α 103.00(1), β 120.78(3), γ 97.68(2)°, R 0.0235, R_w 0.0247 for 5575 observed reflections] has a novel centrosymmetric dimeric structure. Each neodymium is eight-coordinate (4,4 bicapped trigonal prism) with two terminal chelating dmpz ligands [ Nd -N 2.400(2), 2.413(3), 2.422(3), 2.426(3)Ǻ], two bridging dmpz ligands [ Nd -N 2.509(2), 2.511(2)Ǻ], and, unexpectedly, two bridging tetrahydrofuran ligands [ Nd -O 2.792(2), 2.757(2)Ǻ].