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

Divalent 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 {Cu 2 (OCO) 2 } dimeric units. {[Cu(ip)(3‐pina)]·H 2 O} n ( 2 , 3‐pina = 3‐pyridylisonicotinamide) exhibits similar dimeric units, but in contrast to 1 these are connected into a non‐interpenetrated 3D 6 5 8 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 4 12 6 3 pcu networks in contrast to 2 . Use of 5‐hydroxyisophthalate (H 2 hip) as a precursor afforded a mixture of {[Cu 2 (hip) 2 (3‐pina) 4 ]·9.5H 2 O} n ( 5 ) and [Cu(hip)(3‐pina)] n ( 6 ). Compound 5 shows a 2D interdigitated structure with [Cu(hip)] n coordination polymer layers featuring {Cu 2 (OCO) 2 } dimeric units and pendant 3‐pina ligands, while 6 also showed a dimer‐based 4 12 6 3 pcu network. Use of the very sterically bulky 5‐ tert ‐butylisophthalate (tbip) ligand afforded the 1D chain coordination polymer {[Cu(tbip)(3‐pina) 2 (H 2 O)]·H 2 O} 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 {Cu 2 (OCO) 2 } dimeric units in 1 . Thermal decomposition behavior is also discussed.