Rational Design of Mono-, Bi-, and Tetranuclear Macrocyclic Oxamido−Metal Complexes via Stepwise Complexation

Abstract

By using the macrocyclic oxamido−copper(II) complex as a building block and N3- and Cl- as auxiliary bridged groups, a binuclear complex and two tetranuclear complexes derived from the binuclear species have been prepared by stepwise synthesis and characterized. Their formulas are Cu(μ-exoO2)cyclam (1), [Cu(μ-exoO2)cyclamCu(tmen)](ClO4)2·H2O (2), {[Cu(μ-exoO2)cyclamCu(μ-1,3-N3)0.5(tmen)]2(ClO4)4, [Cu(μ-exoO2)cyclamCu(μ-1,3-N3)0.5(tmen)]2(ClO4)2} (3), and [Cu(μ-exoO2)cyclamCu(μ-Cl)0.5(tmen)]2(ClO4)3 (4), where tmen = N,N,N‘N‘-tetramethylethylenediamine and (exoO2)cyclam = 1,4,8,11-tetraazacyclotradecanne-2,3-dione. The structure of complex 1 consists of the neutral copper(II) complex of the [14]N4 macrocyclic oxamido dianion, and the packing of the molecules along the b orientation results in a novel one-dimensional wavelike chain through weak coordination bonds and hydrogen bonds. The structure of complex 2 consists of binuclear cations, a weakly coordinated water molecule, and perchlorate anions, and the structures of 3 and 4 consist of tetranuclear cations derived from binuclear species through azide and chloride ligands, respectively, and perchlorate anions.