Synthesis, crystal structures and magnetism of two coordination compounds constructed from 2,5-disulfonylterephthalate ligand

Two coordination compounds with novel sulfonate–carboxylate ligand of 2,5-disulfonylterephthalate acid (H4DSBDC), namely, [Ni(2,2′-bpy)(H2O)4](DSBDC)0.5 (1) and [Mn(DSBDC)0.5(2,2′-bpy)(H2O)2]n (2) (2,2′-bpy = 2,2′-bipyridyl), have been synthesized. In situ formation of H4DSBDC ligand derived from 5-sulfonyl-1,2,4-benzenetricarboxylic acid is unprecedented and involves a fundamentally new substitution of sulfonate for carboxylate to in situ ligand synthesis reaction. Compound 1 has a mononuclear nickel [Ni(2,2′-bpy)(H2O)4]2+ motif charged with tetraanionic DSBDC4− ion. The [Ni(2,2′-bpy)(H2O)4] cations and DSBDC4− anions are linked by extensive hydrogen bonds to form a three-dimensional supramolecular structure. Compound 2 is a one-dimensional polymeric chain based on the dinuclear Mn2 units. The one-dimensional chains are linked by hydrogen bonds and π–π interactions to form a three-dimensional supramolecular structure. The temperature-dependent magnetic susceptibility data of 1 and 2 have been investigated. The Curie constant C and Weiss constant θ are 1.29 cm3 K mol−1 and −1.61 K for compound 1, respectively, revealing antiferromagnetic interactions between the Ni(II) ions. The magnetic data of 2 are fitted with the dinuclear Mn2 model giving the best fitting results of g = 2.04, J = −0.68, and zj′ = −0.016 cm−1, which indicate the antiferromagnetic interactions are present in 2.