Crystal Structure and Magnetic Property of a 2-D Hexa-Circular Ring Cu(II)/Na(I)-Substituted Sandwich-Type Arsenotungstate

A new compound H-8[NaCu5Cl(H2O)(3)(B-alpha-AsW9O33)(2)] 24H(2)O (1) is synthetized by the reaction of the CuCl2 2H(2)O and Na-27[NaAs4W40O140] 60H(2)O in aqueous solution, which is constructed from a {Cu5Na} hexagon moiety sandwiched by two trilacunary [B-alpha-AsW9O33](9-) units. The structure is determined by single-crystal X-ray diffraction technique and further characterized by IR spectroscopy. Single-crystal X-ray diffraction analysis reveals that 1 is built by two trilacunary [B-alpha-AsW9O33](9-) units incorporating a {Cu5Na} hexagon moiety and further linked to each other to form an infinitely extended 2-D network via Cu-O-W bridges. Notably, magnetic measurement demonstrates that the occurrence of intramolecular ferromagnetic Cu-Cu interactions within {Cu5Na} hexagon moiety.