A novel 3D framework with vertex- and edge-sharing Δ-ribbons extended by ip2− connectors, {[Co7(H2O)2(μ3-OH)4(atz)2(ip)4]·5H2O}n (atz− = 5-amino-tetrazolate and ip2− = isophthalate), exhibits a two-step field-induced metamagnetic transition from an antiferromagnetic ordering to a weak spontaneous magnetization state by spin-competition at 2.0 KOe, followed by a spin-flop transition at 22.5 KOe.
