Recent advances in polyoxothiometalate chemistry

Despite the proliferation of tungstate and molybdate polyoxometalates (POMs) the inclusion of sulfides into these structures proved to be challenging. The use of appropriate preformed thiomolybdate building blocks has over recent years developed into an extensive field with a wide range of diverse structural features and sizes. Initial explorations focused largely either on a combinatorial approach of POM and thiomolybdate dimeric units or a self-condensation approach which gave ring-shaped structures. Over the past ten years these structural archetypes have been challenged; new design approaches led to the generation of fundamentally new building blocks and multicomponent systems featuring well-defined structural fragments which can self-organize in numerous different ways forming a wide variety of diverse structural features, often of remarkably high nuclearity. The unique properties and high tunability potential of the system has proven valuable, with examples of POTM systems exhibiting highly diverse structural motifs and highly promising properties in catalytic applications. In this mini-review we describe the methodologies that have been used to construct materials with important catalytic and structural properties. The discussion does not aim to provide an exhaustive review of the field but rather focuses on the recent developments that occurred the last decade.