Chemistry at the apical position of square-pyramidal copper(II) complexes: Synthesis, crystal structures, and magnetic properties of homopolynuclear complexes with azido bridges containing [Cu(AA)(BB)]+ moieties (AAÂ =Â acetylacetonate; BBÂ =Â 1,10-phenan

Three new homopolynuclear complexes with azido bridges have been obtained by using [Cu(AA)(BB)]+ building-blocks (AA = acetylacetonate; BB = 1,10-phenanthroline or 2,2′-bipyridine): [{Cu(acac)(phen)}2(μ1,3-N3)](ClO4) · 2H2O (1), [{Cu(acac)(phen)(ClO4)}2{Cu(phen)(μ1,1-N3)2}2] (2), [{Cu(acac)(bipy)}2(μ1,3-N3)]3(ClO4)3 · 3.75H2O (3). The cryomagnetic investigation of the tetranuclear complex, 2, reveals ferromagnetic interactions between the copper ions.