Synthesis, structure and magnetic properties of a pair of copper dicarboxylate/dipyridylamine coordination polymers with a non-interpenetrated CdSO4 topology

{[Cu(iph)(dpa)]·0.5H2O}n (1, iph = isophthalate, dpa = 4,4′-dipyridylamine) and [Cu(tdc)(dpa)]n (2, tdc = 2,5-thiophenedicarboxylic acid) form non-interpenetrated 3-D coordination CdSO4 lattices (658 topology). Variable temperature magnetic studies show the presence of weak antiferromagnetic coupling within the {CuOCO}2 dimers in both complexes, with J = −2.66(3) and −1.68(5) cm−1 for 1 and 2, respectively.