Iron, copper, and cobalt complexes of hydrotris(3-phenylpyrazolyl)borate and dihydrobis(3-phenylpyrazolyl)borate. Synthesis and X-ray crystallographic characterization

The scorpionate ligands containing 3-phenylpyrazole have been identified as possessing intermediate steric bulk, due to the wide range of structural t ypes that have been characterized in complexes of these ligands. In this pa per, we report the syntheses and structures of a number of complexes contai ning hydrotris(3-phenylpyrazol-1-yl)borate and dihydrobis(3-phenylpyrazolyl )borate which further manifest the versatility of these ligands. The synthe ses and solid-state structures of Tp(Ph)Fe(SCN)(THF) (I), Tp(Ph) Fe(NO3)(2) (II), Tp(Ph)CuCl(pz(Ph)) (III), Tp(Ph)Cu(SCN)(pz(Ph)) (IV), Bp(2)(Ph) Co ( V), and Tp(Ph)Bp(Ph)Co (VI) are reported (Tp(Ph) = hydrotris(3-phenylpyrazo lylborate); Bp(Ph) = dihydrobis(3-phenylpyrazolylborate); pz(Ph) = 3-phenyl pyrazole). Compound I displays a trigonal bipyramidal coordination sphere, while III and IV are square-pyramidal. Compound H contains one monodentate and one bidentate nitrate ligand in a distorted octahedral coordination sph ere. Compound V is tetrahedral and VI is octahedral with an agostic Co-H in teraction in the sixth coordination site. (C) 2001 Elsevier Science Ltd. Al l rights reserved.