Product change of molecule-magnetic material synthesis induced by magnetic field in hydrothermal system

4-(imidazol-1-yl) benzoic acid (HL, L=C10H7N2O2), Copper sulfate, and sodium azide were selected as precursors, an interesting case of magnetic field-induced change in the final product of molecule-magnetic materials was observed. Without external magnetic field, the only green single crystal G [Cu5(C10H7N2O2)4 (N3)2(SO4)2]n was prepared, but under 0.2 T external magnetic field, the other blue violet single crystal B [Cu(C10H7N2O2)2]n was found beside the green single crystal G. The product prepared under magnetic field comprises ca 34% B and 66% G. It indicates that the magnetic field induction is a dominating factor to the final product of self-assembly reaction for the metal-organic complex. The experiments have suggested a kind of effective control means to fabricate new molecule-magnetic materials under mild magnetic field induction.

► A new transfer state is emerged under magnetic field induction.
► Magnetic field induction is a dominating factor to the final product of self-assembly reaction for metal-organic complex.
► An important method to fabricate new molecule-magnetic materials under mild magnetic field induction.