Binuclear and mononuclear copper(II) chlorido complexes with hindered neutral N3 type ligands: Influence of ligand framework and charge on their structure and physicochemical properties

Abstract Mononuclear copper(II) dichlorido complexes [Cu(L n ′)Cl 2 ] ( 1 ( n  = 1) and 2 ( n  = 0)) of the neutral N3 type ligands, tris(3,5-diisopropyl-1-pyrazolyl)methane (L1′) and tris(3,5-dimethyl-1-pyrazolyl)methane (L0′) were synthesized and the influence of ligand framework and charge on their structure and physicochemical properties was investigated. From reaction with one equivalent of sodium perchlorate, binuclear copper(II) µ-chlorido complexes [Cu(L n ′)(µ-Cl)] 2 (ClO 4 ) 2 ( 3 ( n  = 1) and 4 ( n  = 0)) were obtained. All the structures were determined by X-ray crystallography. These complexes were also characterized by spectroscopic techniques, namely, UV–Vis/DR, IR/far-IR, and ESR spectroscopy. For the binuclear complexes, variable temperature magnetic susceptibility measurements generate J -coupling constants of −3.0(1) and +4.33(8) cm −1 for 3 and 4 respectively; the Cu‐Cl‐Cu angles are 96.89(3) and 96.11(5) degrees respectively.