Synthesis, Characterization, and Crystal Structures of Scorpionate Complexes with the Hydrotris[3-(2′-thienyl)pyrazol-1-yl]borate Ligand.

Six scorpionate complexes of group 10-12 metal elements (CuI, CuII, ZnII, and CdII) containing the anionic hydrotris[3-(2′-thienyl)pyrazol-1-yl]borate (TpTn) ligand were prepared from the reaction of the thallium(I) salt of TpTn with the corresponding metal acceptors in chloroform solution. The air- and heat-stable complexes were characterized by analytical and spectroscopic methods (IR, conductivity, ESI-MS, 1H NMR and 13C NMR solution data) and structurally characterized by single-crystal X-ray studies. The ZnII complexes [Zn(TpTn)X] (X = Cl or Br) contain a tripodal tridentate TpTn ligand, in which the tetrahedral metal environment is completed by a halide; in [Cd(TpTn)2], cadmium is found in an octahedral environment coordinated by two TpTn ligands. In [Cu(TpTn)(PPh3)] ·CHCl3 and [Cu(TpTn)(OC(O)CH3)], TpTn is also coordinated in the tripodal fashion, in which the copper environment is completed by a triphenylphosphine ligand in the former complex and by a symmetrically coordinated bidentate acetate ligand occupying trans-coordinated sites in the latter complex. The reaction of [Zn(TpTn)X] with an excess amount of [Tl(TpTn)] in MeOH yielded [Zn(TpTn)2] and TlX, whereas the reaction of [Zn(TpTn)X] with Na(Tp) gave [Zn(TpTn)2] and [Zn(Tp)2] in a 1:1 molar ratio but not [Zn(TpTn)(Tp)]. By contrast, the reaction of [Tl(TpTn)] with copper(II) sulfate monohydrate in chloroform gave a green powder, which was identified as the [(Hpz3Tn)4CuSO4](∞|∞) coordination polymer containing OSO2 O bridging sulfate groups and four coordinated pyrazole ligands on each metal center, the latter of which arises from the decomposition of the TpTn ligand through B-N bond breaking. Similarly, the interaction between [Tl(TpTn)] and platinum(II) diiodide in chloroform/DMSO proceeded through TpTn decomposition to afford a monomeric trans-[(Hpz3Tn)2PtI2] ·2(CH3)2SO complex, wherein two neutral pyrazole ligands are coordinated to the PtII center. [ABSTRACT FROM AUTHOR]