Copper glutarate coordination polymers with dipyridylamide ligands: Effect of donor disposition and steric bulk on structure

A structurally diverse series of divalent copper glutarate coordination polymers incorporating dipyridylamide ligands has been prepared and structurally characterized. {[Cu2(glu)2(3-pina)]·3.5H2O}n (1, glu = glutarate, 3-pina = 3-pyridylisonicotinamide) manifests a 3D pcu network constructed from [Cu(glu)]n layers containing {Cu2(OCO)4} paddlewheel dimers. Increasing the steric bulk of the glutarate ligand afforded [Cu2(dmg)2(3-pina)]n (2, dmg = 3,3-dimethylglutarate), which shows a (4,4) grid structure based on linked [Cu(dmg)]n chains containing similar {Cu2(OCO)4} paddlewheel dimers. {[Cu(glu)(3-pna)(H2O)]·H2O}n (3, 3-pna = 3-pyridylnicotinamide) has a simple (4,4) grid-like layer structure with isolated copper atoms, while {[Cu(glu)(4-pna)(H2O)]·H2O}n (4, 4-pna = 4-pyridylnicotinamide) possesses a 2-fold parallel interpenetrated (6,3) herringbone lattice. Increased steric bulk and counterion inclusion in [Cu3(Hmg)2(4-pna)4(SO4)2(H2O)4]n (5, meg = 2-methylglutarate) results in a 1D ribbon structure. Thermal properties are also investigated.