Nature of the LnIII-CoII magnetic interactions in compounds [Ln2Co3(C5H4NPO3)6] · 4H2O with open-framework structures

This paper reports a series of isomorphous heterometallic phosphonate compounds with formula [Ln2M3(C5H4NPO3)6] · 4H2O (Ln2M3; M = CoII or ZnII; Ln = LaIII, CeIII, PrIII, NdIII, SmIII, EuIII, GdIII, TbIII, DyIII). The nature of LnIII-CoII magnetic interactions in Ln2Co3 is revealed by a comparison with their LnIII-ZnII analogues.