Different Metal Aggregation in Copper Acetate Chain Coordination Polymers with Dipyridyl Tethers Bearing Hydrogen Bonding Capable Functional Groups

Hydrothermal synthesis has afforded a pair of divalent copper acetate coordination polymers containing either 4, 4′‐dipyridylamine (dpa) or 4‐pyridylisonicotinamide (4‐pina), both of which hydrogen‐bonding capable central functional groups. X‐ray crystallography revealed that both exhibit a 1D chain dimensionality. Use of the kinked tethering ligand dpa produced [Cu(OAc) 2 (dpa)] n ( 1 ), which possesses a simple chain based on dpa linkage of isolated copper ions. On the other hand, employing the straighter amide ligand 4‐pina generated {[Cu(OAc) 2 (4‐pina)] · 0.5H 2 O} n ( 2 ), which exhibits {Cu 2 O 2 } rhomboid dimers formed through bridging acetate ligands. Weak antiferromagnetic coupling [ g = 1.984(3), J = –3.2(3) cm –1 ] was observed within the axial‐equatorial bridged {Cu 2 O 2 } dimers in 2 , with possible ferrimagnetism due to spin canting below 11 K.