CoII, MnII and CuII-directed coordination polymers with mixed tetrazolate-dicarboxylate heterobridges exhibiting spin-canted, spin-frustrated antiferromagnetism and a slight spin-flop transition

Three new paramagnetic ion-directed coordination frameworks, {[Co-4(H2O)(2)(mu(3)-OH)(2)(atz)(2)(nip)(2)]center dot 3H(2)O}(n) (1), {[Mn-4(H2O)(2)(mu(3)-OH)(2)(atz)(2)(nip)(2)]center dot H2O center dot MeOH}(n) (2) and {[Cu-2(H2O)(mu(3)-OH)(atz)(nip)]center dot 2H(2)O}(n) (3), were, respectively, obtained by solvo-/hydrothermal reactions of 5-amino-1H-tetrazole (Hatz), 5-nitroisophathalic acid (H(2)nip) with an inorganic Co-II, Mn-II or Cu-II salt. The former two complexes are two-dimensional (2D) covalent layers built from butterfly-shaped tetranuclear M-4(mu(3)-OH)(2) clusters and double atz(-) and nip(2-) linkers. Whereas complex 3 is a 3D framework with scarcely observed corner-sharing Cu-3(mu(3)-OH) Delta-chains extended by nip(2-) linkages, in which the anionic atz-ligand acts as a reinforcement to consolidate the Delta-chain. Magnetically, due to the interplay of the anisotropy of spin carrier and magnetic exchange interactions from the adjacent spin carriers, the complexes exhibit spin-canted antiferromagnetism with a Neel temperature lower than 2.0 K for 1 and an antiferromagnetic ordering with a slight field-induced spin-flop transition for 2. In contrast, complex 3 with a local Kagome sublattice displays spin-frustrated antiferromagnetic behavior with magnetic ordering at 16.0 K.