Template synthesis, structure and characterization of NiII2PbII and CuII2PbII complexes of macrocycles with a N4O2 donor set

Abstract

The reaction of [N,N′-ethylene- or [N,N′-propane-1,3-diylbis(3-formyl-5-methylsalicylideneiminato)]-metal(II)(M = Cu or Ni) and a diamine (ethylenediamine, propane-1,3-diamine, butane-1,4-diamine or pentane-1,5-diamine) in the presence of lead(II) ion gives macrocyclic complexes [Pb(ML^m,n)₂]X₂[H₂L^m,n= macrocycle formed by the condensation of two molecules of 2,6-diformyl-4-methylphenol and two diamines H₂N(CH₂)_mNH₂ and H₂N(CH₂)_nNH₂; m= 2 or 3 and n= 2–5; M = Cu or Ni; X = CIO₄, PF₆, BPh₄ or BF₄]. They were characterized by elemental analyses, single-crystal X-ray analysis, fast atom bombardment mass, IR, electronic and ESR spectra and magnetic measurements. The crystal structure of [Pb(CuL^3,3)₂][CIO₄]₂ has revealed that the copper(II) ion in each CuL^3,3 is bound at one of the N₂O₂ donor sites and the lead ion is sandwiched by the vacant N₂O₂ sites of two CuL^3,3 entities, providing a square-antiprismatic environment.