Temperature-controlled assembly of a series of inorganic-organic hybrid arsenomolybdates

By controlling the temperature of the reaction systems, three new inorganic-organic hybrid arsenomolybdates [Cu-4(en)(4)O-2(H2O)(2)][(H2As2Mo6O26)-Mo-V] (1) (en = ethylenediamine), [Cu(en)(2)(H2O)](4)[Cu(en)(2)(H2O)(2)]{[Cu(phen)(en)][(AsAsMo9O34)-As-III-Mo-V-O-VI](2)} (phen = 1,10-phenanthroline) (2) and (H(2)en)[Cu(en)(2)][(CuO6)Mo6O18((As3O3)-O-III)(2)]center dot 10H(2)O (3) have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analyses (EDX-SEM), X-ray powder diffraction (XRPD), IR spectroscopy, UV spectroscopy, XPS spectroscopy and thermogravimetric analysis. The experimental phenomenon demonstrates that different temperature ranges correspond to different proportions of oxidized As-III atoms. 1 presents an infinite 1-D chain structure based on the rare secondary building units [H2As2Mo6O26](4-) and unprecedented tetra-Cu clusters [Cu-4(en)(4)O-2(H2O)(2)](4+). The dimer 2 is constructed from a dual-ligand transition-metal complex [Cu(phen)(en)](2+) sandwiched by two scarce [(AsAsMo9O34)-As-III-Mo-V-O-VI](6-) fragments. 3 shows a 1-D chain structure built by [(CuO6)Mo6O18(As3O3)(2)](4-) units and [Cu(en)(2)](2+) bridges. The magnetic measurement indicates that 1 demonstrates the antiferromagnetic couplings within the {Cu-4} cluster.