Dipyridylamide Donor Disposition and Isophthalate Substituent Steric Effect on the Dimensionality and Topology of Divalent Copper Coordination Polymers

Abstract

AbstractDivalent copper coordination polymers containing an isophthalate ligand and a dipyridylamide ligand show different dimensionalities and topologies depending on pyridyl nitrogen donor disposition and the steric bulk of the substituent on the dicarboxylate aromatic ring. According to single‐crystal X‐ray diffraction, [Cu(ip)(3‐pna)]n (1, ip = isophthalate, 3‐pna = 3‐pyridylnicotinamide) shows a (4, 4) layered grid structure based on {Cu2(OCO)2} dimeric units. {[Cu(ip)(3‐pina)]·H2O}n (2, 3‐pina = 3‐pyridylisonicotinamide) exhibits similar dimeric units, but in contrast to 1 these are connected into a non‐interpenetrated 3D 658 cds network. Both [Cu(mip)(3‐pina)]n (3, mip = 5‐methylisophthalate) and [Cu(meoip)(3‐pina)]n (4, mip = 5‐methoxyisophthalate) display dimer‐based 41263 pcu networks in contrast to 2. Use of 5‐hydroxyisophthalate (H2hip) as a precursor afforded a mixture of {[Cu2(hip)2(3‐pina)4]·9.5H2O}n (5) and [Cu(hip)(3‐pina)]n (6). Compound 5 shows a 2D interdigitated structure with [Cu(hip)]n coordination polymer layers featuring {Cu2(OCO)2} dimeric units and pendant 3‐pina ligands, while 6 also showed a dimer‐based 41263 pcu network. Use of the very sterically bulky 5‐tert‐butylisophthalate (tbip) ligand afforded the 1D chain coordination polymer {[Cu(tbip)(3‐pina)2(H2O)]·H2O}n (7), which contains isolated copper ions in contrast to 1–6, and has a curious “butterfly“ resemblance. Very weak antiferromagnetic coupling is seen within the {Cu2(OCO)2} dimeric units in 1. Thermal decomposition behavior is also discussed.