Copper(II/I) complexes of a bulky tris(pyrazolylmethyl)amine ligand

Abstract

The ligand tris[3-(4-methoxyphenyl)-5-methylpyrazol-1-ylmethyl]amine (L), the copper(II) complexes [CuLCl₂] 1, [CuLCl][SbF₆] 2 and [CuL(H₂O)][SbF₆]₂3, and the copper(I) complex [CuL][CF₃SO₃] 4 have been prepared. Complexes 1–3 are reduced by [BPh₄]⁻ ion in a range of solvents to afford [CuL]⁺ ion. The [CuL]⁺ ion does not react with dioxygen nor carbon monoxide but does react with chloride ion. Physicochemical and cyclic voltammetry data are reported for 1–4, along with crystal structure analyses of 1–3 and [CuL][CuCl₂]. There are some notable differences between the structures and properties of these copper complexes and those reported for analogues with pyridyl- or imidazolyl amine ligands.