Diverse dimensionalities and structures in copper coordination polymers incorporating substituted aliphatic dicarboxylate ligands and 4,4′-bipyridine

Abstract Hydrothermal synthesis has afforded a series of divalent copper coordination polymers with substituted glutarate ligands and the rigid rod tether 4,4′-bipyridine (bpy): {[Cu(Hdmg) 2 (bpy)]·H 2 O} n ( 1 , dmg = 3,3-dimethylglutarate), {[Cu 2 (dmg)(bpy) 2 ](ClO 4 )] n ( 2 ), [Cu 2 (emg) 2 (bpy)] n ( 3 , emg = 3-ethyl, 3-methylglutarate) and [Cu 2 (cda) 2 (bpy)] n ( 4 , cda = 1,1-cyclopentanediacetate). All materials were characterized by single-crystal X-ray diffraction. Compound 1 manifests μ 2 -oxygen bridged [Cu 2 (Hdmg) 4 ] “X”-patterns connected into a ribbon motif by bpy linkers. On the other hand, 2 possesses mixed-valence [Cu I Cu II Cu II Cu I ] tetrameric clusters bridged by dmg ligands and pillared into an 8-connected body-centered cubic ( bcu ) cationic lattice by bpy linkers. Compounds 3 and 4 are structurally very similar, displaying chain motifs with {Cu 2 (CO 2 ) 4 } paddlewheels connected by dicarboxylates, in turn conjoined into (4,4)-grid coordination polymer layers by bpy tethers. Variable temperature magnetic data indicate the presence of very strong antiferromagnetic coupling within the {Cu 2 (CO 2 ) 4 } paddlewheels in the latter two complexes, with g  = 2.30(2) and J  = −352(3) cm −1 for 3 and g  = 2.35(2) and J  = −352(5) cm −1 for 4 . Significant structural contrasts are evident when compared to previously reported divalent copper/4,4′-bipyridine coordination polymers with unsubstituted or 2-methyl substituted glutarate ligands.