Azide-Bridged Copper(II) and Manganese(II) Compounds with a Zwitterionic Tetrazolate Ligand: Structures and Magnetic Properties

Two azide-bridged coordination polymers, [Cu(mptz)(N-3)(2)] (1) and [Mn(mptz)(N-3)(2)H2O] (2), (mptz = N-methyl-4-pyridinium tetrazolate), were synthesized and crystallographically and magnetically characterized. Compound 1 is a neutral 1D coordination polymer in which the Cu-II ions, which are in a square pyramidal surrounding, are linked by double end-on azide bridges in an alternating basal-basal and basal-apical fashion. Compound 2 exhibits a 3D Mn-II-azide coordination framework with the (10,3)-b net topology, in which the double end-on-azide-bridged dimanganese units are inter-linked by single end-to-end azide bridges. The magnetic analyses indicated that 1 behaves magnetically as a quasidimer with an S = 1 ground state due to a strong ferromagnetic interaction through the basal-basal azide bridges and a very weak antiferromagnetic coupling through the basalapical azide bridges. Compound 2 exhibits 3D antiferromagnetic behaviors with T-N = 24.0 K, where the end-to-end and end-on azide bridges mediate the antiferromagnetic and ferromagnetic interactions, respectively.