Synthesis and structural characterization of three dinuclear Copper(II) complexes incorporating pyrazolyl-derived ligands

Abstract

Three new binuclear copper complexes of formulae $\left[ {{\text{Cu}}_{2}^{\text{II}} {\text{Pz}}_{2}^{\text{Me3}} {\text{Br}}_{ 2} \left( {{\text{PPh}}_{ 3} } \right)_{ 2} } \right]$ (1), $\left[ {{\text{Cu}}_{ 2}^{\text{II}} {\text{Pz}}_{2}^{\text{Ph2Me}} {\text{Cl}}_{ 2} \left( {{\text{PPh}}_{ 3} } \right)_{ 2} } \right]$ (2) and $\left[ {{\text{Cu}}_{2}^{\text{II}} \left( {{\text{Pz}}^{\text{PhMe}} } \right)_{ 4} {\text{Cl}}_{ 4} } \right]$ (3) (Pz^Me3 = 3,4,5-trimethylpyrazole, Pz^Ph2Me = 4-methyl-3,5-diphenylpyrazole and Pz^PhMe = 3-methyl-5-phenylpyrazole) have been synthesized and characterized by chemical analysis, FTIR and ³¹P NMR spectroscopy and single-crystal X-ray diffraction. Complex 1 is a doubly bromo-bridged dimer, while complexes 2 and 3 are chloro-bridged dimers. The Cu(II) centers are in a distorted tetrahedral geometry for 1 and 2 and a distorted square pyramidal N₂Cl₃ environment for 3.