Synthetic-Method-Dependent Magnetic Relaxation in a Cobalt(II) Phosphonate Chain Compound

A polar cobalt­(II) phosphonate Co­(bamdpH2)­(H2O) (1) [bamdpH4 = (benzylazanediyl)­bis­(methylene)­diphosphonic acid] is reported. It shows a linear chain structure. The neighboring chains are connected by moderately strong hydrogen bonds forming a supramolecular layer. The interlayer spaces are filled with the organic groups of the phosphonate ligands. Compound 1 displays the coexistence of single-chain magnet behavior and canted antiferromagnetism below 2.8 K. Moreover, the magnetic dynamics is strongly dependent on the synthetic methods, a phenomenon that has not been documented before.