A dodecanuclear copper(II) cage self-assembled from six dicopper building units

Reaction of the dinucleating phenol-based ligand, H(3)bpmp (2,6-bis-[(3-hydroxy-propylimino)-methyl]4- methyl-phenol), with Cu2+ ions in the presence of a hybrid base (NEt3 and NaN3) necessary for the in situ generation of required numbers of hydroxido ions, results in the formation of a novel NO3- capped and HO- supported {Cu-12} coordination complex {Cu-6(mu(3)-OH)(3)(mu(3)-Hbpmp)(3)(mu(3)-NO3)}(2)(NO3)(2)(OH)(2)center dot 2H(2)O center dot 2MeOH (1). When the components are combined in right proportions (metal : ligand : NEt3 : NaN3 = 2 : 1 : 3 : 2) in MeOH, twelve Cu2+ ions assemble in a cuboctahedral geometry, containing six square and eight triangular faces around a considerable void space. Six of the eight [Cu-3] triangular faces are bound by the six Hbpmp(2-) ligands with six free pendant propanol arms around the central hexagonal plane. X-ray structure determination indicates new geometrical features for the core formation and reveals the face-capping potential of the H(3)bpmp ligand for the growth of a cuboctahedral coordination cage with the support of anions like HO and NO3. The experimentally observed (J/k(B) = -173 K) strong antiferromagnetic coupling within the Cu-12 complex has been justified by the DFT calculations.