Assembly of a POM-based hybrid compound consisting of both helical and interdigitated motifs

A new compound, {[Ag(DF)2]4SiW12O40} (1), (DF = 4,5-diazafluoren-9-one), has been hydrothermally synthesized, and characterized by elemental analyses, IR, TG and single crystal X-ray diffraction. A structural feature in 1 is that the adjacent [Ag(DF)2]2(SiW12) fragments are linked together by H-bonds to achieve left- and right- handed helical chains with the pitch ca. 26.3 Å. Furthermore, these helical chains are linked via H-bonds forming a poly-pendant layer, in which the [Ag(DF)2] moieties as pendants are appended to the two sides of the layer. Interestingly, adjacent layers mutually engage in an interdigitated pattern to result in a novel a 2D + 2D → 3D architecture. The electrochemical studies show that 1 has a good electrocatalytic activity toward reduction of hydrogen peroxide molecules.