Syntheses And Electrocatalysis Of Coordination Compounds Based On A Resorcin[4]arene Ligand

By employing a newly bowl-like tetrakis((benzimidazolyl)methyl)resorcin[4]arene(L)ligand,seven compounds,three of which contain Keggin type polyoxometalates,[Co3L2Cl2(DMF)4][SiW12O40]·2EtOH·3H2O(1),[Co8/3L2Cl14/3][H10/3 SiW12O40]·3DMF·4EtOH·7H2O(2),[Co4L2(DMF)6(H2O)6][CoW12O40]0.5[SiW12O40]0.5·3OH·7DMF·5H2O(3),[MnLCl]·Cl(4)and[NiLCl]·Cl(5),[CoLCl]·Cl·2DMF(6)and[NiLCl]·Cl·2DMF(7),have been synthesized under solvothermal conditions.All of the frameworks of 1-3 are formed by the connection of Co(II)and L.1 shows a three-dimensional(3D)framework,while 2 and 3 exhibit 2D layers.The uncoordinated Keggin POMs in 1-3 were located in the cavities formed by two bowl-like resorcin[4]arenes to form sandwich fashions.4-7 display mononuclear structures.In compounds 4 and 5,?-? interactions between the benzene rings of L ligands connect the monostructures to generate 3D supramolecular frameworks.In compounds 6 and 7,hydrogen bonds among the L ligands linked the monostructures to form supramolecular layers.The chemical stabilities of 1 and 2 were studied in several organic solvents.Electrocatalytic reduction of sodium bromate and oxidation of ascorbic acid by using 1-3 as electrocatalysts have been investigated.