Comparative investigation of the interaction of Zn(II), Cd(II), Ag(I) and Pb(II) with dibenzo-substituted macrocyclic ligands incorporating both symmetrically and unsymmetrically arranged N, O and S donors: synthetic, solution and X-ray studies

Abstract

Comparative investigation of the interaction of Zn(II), Cd(II), Ag(I) and Pb(II) with dibenzo-substituted macrocyclic ligands incorporating both symmetrically and unsymmetrically arranged N, O and S donors: synthetic, solution and X-ray studies, Supramolecular Chemistry, 24:8, 572-584, A comparison of the interaction of Zn(II), Cd(II), Ag(I) and Pb(II) with a matrix of 18, 17-membered, dibenzo-substituted macrocyclic ligands (1-18) incorporating nitrogen, oxygen and/or sulfur heteroatom sites that share the same carbon backbone is reported. Potentiometric log K data for complexes of these metals with 5, 6, 8 and 9 incorporating unsymmetric arrangements of their donor sets were obtained and the results compared with previously determined stability data for the remaining symmetrical and unsymmetrical ligand complexes forming the above matrix. Structure -function relationships underlying the relative magnitudes of the respective log K values are discussed, with emphasis given to the influence of both the donor atom set and the donor atom sequence on the nature of the resulting complexes. The X-ray structures of [CdL(NO 3 )] (NO 3 )·CH 3 CH 2 OH (L ¼ 4, SN 4 donor set), [CdL(NO 3 ) 2 ]·CH 3 OH (L ¼ 7, ON 4 donor set), [AgL]PF 6 (L ¼ 4, SN 4 donor set) and [AgL]PF 6 (L ¼ 9, OSN 3 donor set) are presented along with that of the metal-free diprotonated nitrate salt (LH 2 )(NO 3 ) 2 (L ¼ 6, S 2 N 3 donor set).

Synthesis and structural characterization of new N2O2-donor Schiff base macrocycles and their silver(I) coordination polymers

“…However, for this type of applications, due to the nature of the macrocyclic ligands, endo-coordinated macrocyclic complexes (metal ion is bonded inside macrocyclic cavity) are almost exclusively investigated. Considering this type of coordination and donor set atoms (N, O), a large number of investigations were done on unsymmetrical macrocyclic systems [5][6][7], particularly on compartmental macrocycles [8,9]. Another, much less investigated binding mode is the exo-coordination, where the metal ion is linked outside the macrocyclic ring.…”