The tetraazido dinuclear Cu(II) complexes 1 and 2 of the polyaza-polyoxa macrocyclic ligands 4, [24]ane-N2Oe, and 5, [24]ane-N602, respectively, have been prepared, and their crystal structures have been determined. In both cases the two copper ions are contained inside the molecular cavity and are bound to the ONO and NNN chelating subunits situated at the two poles of the macrocycles 4 and 5, respectively. 1 crystallizes in the monoclinic system, space group P2\/n (a = Dihedral Angles N(l)-C(2)-C(3)-0(4) 59.6 C(2)-C(3)-0(4)-C(5) -165.6 C(3)-0(4)-C(5)-C(6) 178.9 0(4)-C(5)-C(6)-0(7) 65.3 C(5)-C(6)-0(7)-C(8) -167.1 C(6)-0(7)-C(8)-C(9) 158.9 O(7)-C(8)-C(9)-O(10) -69.4 C(8)-C(9)-O(10)-C(U) 179.9 C(9)-O(10)-C(ll)-C(12) -179.3 O(10)-C(ll)-C(12)-N(13) -59.8 C(ll)-C(12)-N(13)-C(14) -166.6 C(12)-N(13)-C(14)-C(15) 175.1 N(13)-C(14)-C(15)-0(16) 61.4 C(14)-C(15)-0(16)-C(17) -176.2 C(15)-0(16)-C(17)-C(18) 169.1 0(16)-C( 17)-C( 18)-0(19)64.8 C(17)-C(18)-O(19)-C(20) -174.0 C(18)-O(19)-C(20)-C(21) 170.2

Die makrocyclischen Cu(II)‐Komplexe (I) und (II) werden durch die Umsetzung von Cu(II)‐perchlorathexahydrat mit den Makrocyclen in Methanol und nachfolgender Metathesereaktionen der entstehenden Perchlorate mit Na‐azid dargestellt (keine Ausb.‐Angaben).