Organoamido‐ and aryloxo‐lanthanoids. XIII [1]. Organometallic compounds of the lanthanoids. CV [2]. New Lanthanoid(III) Complexes with Pyrazolate Ligands

The complexes Er(Me2pz)3(thf) and Ln(Ph2pz)3(thf)n (Ln = Sc, Y, Gd, Er, n = 2; Ln = Lu, n = 3) (Me2pz− = 3,5‐dimethylpyrazolate, thf = tetrahydrofuran, Ph2pz− = 3,5‐diphenylpyrazolate) have been prepared by reaction of the lanthanoid metal with bis(pentafluorophenyl)mercury and the pyrazole in thf. The Ln(Ph2pz)3(thf)2 complexes are considered to be eight coordinate with three η2‐Ph2pz ligands. Other lanthanoid pyrazolate complexes, Y(pz)3(thf)2, La(Me2pz)3(thf), Cp2Ln(Me2pz)(thf)n (Ln = Y, Lu, n = 0; Ln = Lu, n = 1), (C5Me5)2Y(pz)(thf), (C5Me5)2Y(Mepz)(thf), (C5Me5)2Y(Me2pz)(thf)2 (pz− = pyrazolate, Mepz− = 3‐methylpyrazolate, Cp = cyclopentadienyl) have been synthesized by reaction of LnCl3, Cp2LnCl, or (C5Me5)2LnCl with the appropriate sodium pyrazolate in thf. The structure of Ln(Me2pz)3(thf) (Ln = La or Er) is considered to be a symmetrical dimer with four chelating and two bridging Me2pz groups, and two bridging thf ligands, whereas the cyclopentadienyl complexes are most likely dimers with bridging pyrazolate groups, and lattice thf of solvation.