The interaction of transition and post-transition metal ions with 14- and 16-membered trans N2X2-donor macrocycles (X = NH, O, S)

Abstract

A comparative investigation of the 1:1 (metal/ligand) complex stabilities of 14- and 16-membered derivatives of dibenzo-substituted macrocycles incorporating trans-N2O2, -N2S2 and -N4 donor sets towards Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Ag(I) and Pb(II) ions has been carried out with emphasis on the influence of systematic donor atom variation on the respective 1:1 stability constants. For comparison, previously determined log K values for corresponding cis-N2O2 and -N4 donor ligand systems are also discussed. The crystal structures of the nickel(II) thiocyanate complexes of the 14-membered N4(diamine) and precursor N4(diimine) macrocycles are also presented. C20H24N6NiS2 crystallised in the triclinic space group P1̄ (No. 2) with a = 8.913(2) Å, b = 9.441(2) Å, c = 13.583(3) Å, α = 94.29(2)°, β = 107.48(2)°, γ = 90.90(2)° and Z = 2. C20H20N6NiS2·CH3CN crystallised in the monoclinic space group P21/n (No. 14) with a = 10.321(2) Å, b = 13.855(8) Å, c = 17.435(1) Å, β = 102.59(10)° and Z = 4. Show more