Bis[hydrotris(4-chloro-3,5-dimethylpyrazolyl)borato]nickel(II)

The title compound, [Ni(C15H19BCl3N6)(2)] or Ni(Tp*(Cl))(2), adds to the list of structurally characterized bis(trispyrazolyl) borate-nickel(II) complexes. The two facially coordinating N-donor Tp*(Cl) ligands impose pseudo-octahedral coordination on the nickel(II) center. The asymmetric unit consists of two half molecules, primarily differing in the torsion angles of the coordinated pyrazole rings relative to the central B-Ni-B axis of the molecules; each molecule is centrosymmetric. An average overall Ni-N distance of 2.104 (15) angstrom is observed, typical of octahedral NiN6 coordination spheres and this class of compound. The title compound readily forms good quality crystals, while its 4-H analog, Ni(Tp*)(2), does not. This characteristic is attributed to close contacts between the pyrazole 4-chloro-substituents on adjacent molecules.