Formation of Gd coordination polymer with 1D chains mediated by Bronsted acidic ionic liquids

One dimensional coordination polymer Gd[(SO₄)(NO₃)(C₂H₆SO)₂] (1) is prepared through the mediation of Bronsted acid ionic liquid, which crystallized in the monoclinic space of C2/c. In this polymer, adjacent Gd atoms are linked by two SO₄^2- ions to generate a 1-D chain, and all oxygen atoms in SO₄^2- groups are connected to three nearest Gd atoms in µ³:η¹:η¹:η² fashion. Gd, S and N from SO₄^2- and NO₃^- are precisely coplanar. The planar is coordinated by a pair of DMSO molecules, which is parallel and linked by hydrogen bonding to form a three-dimensional supramolecular network. Magnetic susceptibility measurement of 1 reveals weak antiferromagnetic interactions between the Gd (III) ions. It exhibits relatively large magneto-caloric effect with –ΔS_m=28.8 J Kg⁻¹ K⁻¹ for ΔH=7 T.