Stoichiometry and Properties of Tetranuclear Octahalo Copper(II) Complexes, L4cu4x8; (L = 2-Methylpyrrolidine, , X = Cl Or Br) and The Dimer L4cu2cl4 in Aprotic Media
The chemistry of polynuclear halo(amine)Cu(I) complexes has fascinated chemists for many years ago. Progress in understanding the Stoichiometry, structural, chemical and photophysical properties of polynuclear halo(amine)Cu(I) complexes has advanced considerably over the last years [1-7]. This work reports a new family of tetranuclear Cu complexes L4Cu4X8; L = 2-Methylpyrrolidine, X = Cl or Br. Two electron oxidant Br2 has been used to prepare L4Cu4Br8 from the respective [LCuBr]4 complex. The dimeric complex, L4Cu2Cl4 is also prepared by the direct reaction of anhydrous CuCl2 with piperidine in O2-free CH2Cl2. These complexes are isolated as stable solids. They are easily soluble in aprotic solvents as CH2Cl2 or PhNO2. Cryoscopic measurements support tetranuclear core structure for L4Cu4X8. Due to the importance of such class of compounds we aim to (i) Synthesize and characterize the new Octahalo copper(II) complexes of 2-Methylpyrrolidine (L) and (ii) Study their thermal behavior. The tetranuclear Copper complexes of the formula L4Cu4X8; L = 2-Methylpyrrolidine, X =Cl or Br were synthesized and characterized. Two electron oxidant Br2 has been used to synthesize L4Cu4Br8 from the respective [LCuBr]4 complex. The dimeric complex, L4Cu2Cl4, was synthesized by the direct reaction of anhydrous CuCl2 with L = 2-Methylpyrrolidine in O2 - free CH2Cl2. Cryoscopic measurements support tetranuclear core structure for L4Cu4X8. The formulas of the complexes were based on their microanalysis, FT-IR spectra and molar mass determination. The U.V-visible and ESR spectra were used to determine the geometry around the copper centers. Their thermal behavior was studied and related to their structure, Fig.1.