Two extended 5-methyltetrazolate-based magnetic complexes: Synthesis, structure, and magnetic properties

Abstract

Two 5-methyl-tetrazolate (mtz-)-based paramagnetic metal coordination polymers, {[Cu2(H2O)2(mtz) (μ3-OH)(nip)]·H2O}n (1) and [Cu(H2O)(mtz)2]n (2), were obtained in the presence and absence of aromatic 5-nitroisophathalate (nip2-) coligand by varying the preparation methods. Structural determinations reveal that 1 is a three-dimensional (3D) framework with corner-sharing triangular ribbons infinitely extended by ditopic nip2- connectors. In contrast, 2 is a coplanar (4,4) layer constructed from square-pyramidal CuII ions and μ-N1,N4-mtz- linkers, which is further assembled into a 3D supramolecular network by interlayer hydrogen-bonding interactions. Magnetically, spin-frustrated antiferromagnetic ordering is observed in the 3D framework of 1 and canted antiferromagnetic behavior with a slight spin-flop transition is presented in 2, which are structurally resulting from the locally Δ-ribbon in 1 and asymmetric magnetic superexchange mediated by the μ-N1,N4-mtz- bridge of 2. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.