A novel organic–inorganic hybrid sandwich-type germanotungstate with discrete [Fe4(en)2(α-GeW9O34)2]8− polyoxoanions and 1-D [Fe4(en)(α-GeW9O34)2]n8n− polymeric chains

Abstract

A novel organic–inorganic hybrid sandwich-type germanotungstate [enH2]8[Fe4(en)(α-GeW9O34)2] [Fe4(en)2(α-GeW9O34)2]·en·14H2O has been synthesized by reaction of K8Na2[A-α-GeW9O34]·25 H2O, FeCl3, Ce(NH4)4(SO4)4·4H2O and en (en = ethylenediamine) under hydrothermal conditions and characterized by elemental analyses, IR spectrum, powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS) and single-crystal X-ray diffraction. To our knowledge, 1 represents the first organic–inorganic hybrid sandwich-type germanotungstate with discrete [Fe4(en)2(α-GeW9O34)2]8 − polyoxoanions and 1-D [Fe4(en)(α-GeW9O34)2]n8n − polymeric chains in polyoxometalate chemistry. Thermogravimetric curve of 1 between 25 and 700 °C indicates two steps of weight loss. Variable-temperature magnetic susceptibilities of 1 exhibit the ferromagnetic interactions within the belt-like tetra-FeIII clusters mediated by the oxygen bridges.