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 alpha,omega-dicarboxylic acids (sebacic (H(2)seb), suberic (H(2)sub), succinic (H(2)suc) and adipic (H(2)adip)) and 3-aminopyridine (3-apy) are described: [Cu(Hsub)(2)(3-apy)(2)center dot 2CH(3)OH](n) (1); [Cu(Hseb)(2)(3-apy)(2)center dot 4CH(3)OH](n) (2); [Cu(Hsuc)(2)(3-apy)(2)](n) (3); [Cu(adip)(3-apy)(2)](n)center dot n(H(2)adip) (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 (adip(2-)) 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. (C) 2009 Elsevier Ltd. All rights reserved.