Cu(II) coordination polymers incorporating 3-aminopyridine and flexible aliphatic dicarboxylate ligands: Synthesis, structure and magnetic properties

The synthesis, structural chemistry and magnetic properties of a series of new Cu(II) polymers with α,ω-dicarboxylic acids (sebacic (H2seb), suberic (H2sub), succinic (H2suc) and adipic (H2adip)) and 3-aminopyridine (3-apy) are described: [Cu(Hsub)2(3-apy)2·2CH3OH]n (1); [Cu(Hseb)2(3-apy)2·4CH3OH]n (2); [Cu(Hsuc)2(3-apy)2]n (3); [Cu(adip)(3-apy)2]n·n(H2adip) (4). All four compounds feature a bis-monodentate bridging mode of the coordinated dicarboxylate moiety. Compounds 1 and 2 exhibit linear chains, whereas compound 3 shows two-dimensional structure. The 3-apy ligand acts as terminal ligand in 1–3. Compound 4 contains a doubly deprotonated adipate (adip2−) that connects Cu centers into linear chains. Additionally, 3-apy acts as a bridge in 4, resulting in the formation of parallel two-dimensional layers distant enough to host neutral molecules of adipic acid. Magnetic susceptibility measurements of compounds 1 and 3 show Curie law behavior indicating that the S = 1/2 Cu(II) spin carriers are magnetically well isolated by the dicarboxylate ligands.

Graphical abstractFour new copper coordination polymers with aliphatic dicarboxylates and 3-aminopyridine have been prepared. The association of monomeric building units leads to the formation of chains or layers through the dicarboxylate moiety and unexpectedly also through 3-aminopyridine.Figure optionsDownload full-size imageDownload as PowerPoint slide