Structural directing roles of isomeric phenylenediacetate ligands in the formation of coordination networks based on flexible N,N′-di(3-pyridyl)suberoamide

Reactions of the flexible N,N′-di(3-pyridyl)suberoamide (L) with Cu(ii) salts in the presence of the isomeric phenylenediacetic acids under hydrothermal conditions afforded three new coordination networks, {[Cu(L)(1,2-pda)]·H₂O}_n (1,2-H₂pda = 1,2-phenylenediacetic acid), 1, {[Cu(L)(1,3-pda)]·2H₂O}_n (1,3- H₂pda = 1,3-phenylenediacetic acid), 2, and {[Cu(L)(1,4-pda)]·2H₂O}_n (1,4-H₂pda = 1,4-phenylenediacetic acid), 3, which have been structurally characterized by X-ray crystallography. Complex 1 forms a single 3,5-coordinated 3D net with the (4²·6⁵·8³)(4²·6)-3,5T1 topology, which can be further simplified as a 6-coordinated (4¹²·6³)-pcu topology. Complex 2 is a 5-fold interpenetrated 3D structure with the (6⁵·8)-cds topology, which exhibits the maximum number of interpenetration presently known for cds and complex 3 is the first 1D self-catenated coordination network. The ligand isomerism of the phenylenediacetate ligands is important in determining the structural types of the Cu(ii) coordination networks based on the flexible L ligands.