Coordination Assemblies of CoII/NiII/ ZnII/CdII with Succinic Acid and Bent Connectors: Structural Diversity and Spin-Canted Antiferromagnetism

Abstract

Four bent ligands, (i) 4,4′-abpt, (ii) 4,4′-Hbpt, (iii) 3,4′-Hbpt, and (iv) 3,3′-Hbpt, as well as H2suc (succinic acid) have been utilized to construct seven coordination polymers: [Co(suc)(4,4′-abpt)(H2O)2]·H2O (1), [M(suc)(4,4′-Hbpt)(H2O)]·2H2O (M = Co for 2, Ni for 3), [Cd(suc)(4,4′-Hbpt)2(H2O)2] (4), [Co(suc)(3,4′-Hbpt)(H2O)3]·H2O (5), [Zn(suc)(3,4′-Hbpt)] (6), and [Zn(suc)0.5(3,3′-bpt)(H2O)] (7) (4,4′-abpt = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole, 4,4′-Hbpt = 1H-3,5-bis(4-pyridyl)-1,2,4-triazole, 3,4'-Hbpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole, and 3,3′-Hbpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole). The crystal structure analysis reveals that 1–3 form similar two-dimensional (2D) layer structures, where the adjacent metal centers are connected by a syn–anti carboxylate bridge from suc ligands to furnish a succinate-metal chain, which is further interlinked by bent ligands. 4–7 form different 1D chains via suc anions, and bpt isomers display versatile coordination modes. The magnetic behav...