Mononuclear Copper(II) Hydroxo Complex: Structural Effect of a 3-Position of Tris(pyrazolyl)borates

Abstract

Abstract New mononuclear nitratocopper(II) complexes ([Cu(NO3){HB(3,5-iPr2pz)3}] (1) and [Cu(NO3){HB(3-tBu-5-iPrpz)3}] (3)) and a novel mononuclear hydroxocopper(II) complex ([Cu(OH){HB(3-tBu-5-iPrpz)3}] (4)) have been prepared. These complexes were characterized by X-ray analysis and IR, UV-vis, and EPR spectroscopies. Except for the dinuclear complex ([{Cu[HB(3,5-iPr2pz)3]}2(μ-OH)2] (2)), the complexes are mononuclear structures having square-pyramidal (1), trigonal-pyramidal (3), and distorted tetrahedral (4) geometry. In comparison with these structures and their physicochemical properties, the structural effects on the alkyl substitutions at the close 3-position in hydrotris(pyrazolyl)borates play an important role in modifying the coordination environment about a copper(II) center and their physicochemical properties.