Chloro-lanthanide, and plutonium complexes containing the hydrotris(3,5-dimethylpyrazol-1-yl)borate ligand:: the crystal and molecular structures of [PrCl(μ-Cl)TpMe2(3,5-Me2pzH)]2 and YbCl2TpMe2(THF)

Reactions of PuCl3 and LnCl(3) (Ln=Pr, Nd) with the stoichiometric amount of KTp(Me2) (Tp(Me2) =HB(3,5-Me(2)pz)(3)) yielded the dimeric [MCl(mu-Cl)Tp(Me2) (Me(2)pzH)](2) compounds (M = Pu (1), Pr (2), Nd (3)). The analogous reaction with YbCl3 afforded the monomeric YbCl(2)Tp(Me2)(THF) complex (4). The crystal and molecular structures of 2 and 4 have been assessed by means of single crystal X-ray diffraction analysis. In 2 each Pr atom is seven-coordinate and is linked to the adjacent metal centre by two bridging chlorine ligands. In 4 the Yb atom is six-coordinate and displays octahedral geometry. 4 undergoes intermolecular rearrangement reactions to yield [YbCl2TPMe2 (Me(2)pzH)]. THF (6) and [YbCl(3)Tp(Me2)](-)[(Me(2)pzH(2))](+) (7). The molecular structures of 6 and 7 were determined by X-ray diffraction. In 6 the tridentate ligand, the two chlorine atoms and the nitrogen atom of the neutral dimethylpyrazole describe a distorted octahedron. 7 consist of discrete [YbCl(3)Tp(Me2)](-) and [(Me(2)pzH(2))](+) ions, with the ytterbium atom of the cation coordinated to three pyrazolyl nitrogens and three chlorine atoms. (C) 1998 Elsevier Science Ltd. All rights reserved.