Rational design of mono-, bi-, and tetranuclear macrocyclic oxamido-metal complexes via stepwise complexation

By using the macrocyclic oxamido-copper(II) complex as a building block and N-3(-) 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(mu-exoO(2))cyclam (1), [Cu(mu-exoO(2))cyclamCu(tmen)](ClO4)(2)center dot H2O (2), {[Cu(mu-exoO(2))cyclamCu(mu-1,3-N-3)(0.5)(tmen)](2)(ClO4)(4), [Cu(mu-exoO(2))cyclamCu(mu-1,3-N-3)(0.5)(tmen)](2)(ClO4)(2) (3), and [Cu(mu-exoO(2))cyclamCu(mu-Cl)(0.5)(tmen)](2)(ClO4)(3) (4), where tmen = N,N,N'N'-tetramethylethylenediamine and (exoO(2))cyclam = 1,4,8,11-tetraazacyclotradecanne-2,3-dione. The structure of complex 1 consists of the neutral copper(II) complex of the [14]N-4 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.