2013) Three 3-amino-1,2,4-triazole-based cobalt(II) complexes incorporating with different carboxylate coligands: synthesis, crystal structures, and magnetic behavior, Journal of Coordination Chemistry, 66:24, 4399-4414, Three 3-amino-1,2,4-triazole (Hatz)-based paramagnetic metal complexes, {[Co 2 (Hatz) 2 (nip) 2 ]·H 2 O} n (1), [Co(atz)(nb)] n (2), and {[Co 3 (H 2 O) 4 (Hatz) 6 (btc) 2 ]·11.5H 2 O} (3) (nip 2− = 5-nitroisophathalate, nb -= p-nitrobenzolate, and btc 3-= 1,2,4-benzenetricarboxylate), were respectively prepared by introducing differently carboxylate-containing rigid coligands. All these complexes were structurally and magnetically characterized by single-crystal and powder X-ray diffractions, elemental analysis, FT-IR spectra, thermogravimetric and magnetic measurements. Complex 1 has a four-connected CdSO 4 -type framework with binuclear subunits periodically extended by ditopic μ-N1, N3-Hatz and carboxylate-containing linkers. Tetrahedral Co II ions in 2 are periodically interlinked into an undulated layer by anionic μ 3 -N1,N2,N3-atz − connectors with deprotonated nb -spacers located on the both sides. By contrast, complex 3 is a centrosymmetric trinuclear molecule aggregated by six neutral μ-N1, N3-Hatz molecules. The structural difference of 1-3 is significantly due to the flexible binding modes adopted by triazolyl and carboxylate groups. Additionally, 1 exhibits a field-induced metamagnetic transition from an antiferromagnetic ordering to a weak ferromagnetic state resulting from the magnetic competition between triazolyl and carboxylate mediators. Instead, comparable antiferromagnetic couplings transmitted by cyclic triazolyl groups are observed in the nearest neighbors of 2 and 3.