Polyoxometalates (POMs) form a large, distinctive class of molecular inorganic compounds of unrivaled electronic versatility and structural variation, with impacts ranging from chemistry, catalysis, and materials science to biology, and medicine. This book covers the basic principles governing the structure, bonding and reactivity of these metal-oxygen cluster anions and the major developments in their molecular science. The book comprises three sections. The first covers areas ranging from topological principles via synthesis and stability to reactivity in solution. It also focuses on the physical methods currently used to extract information on the molecular and electronic structures as well as the physical properties of these clusters. The second part reviews different types of POMs, focusing on those systems that currently impact other areas of interest, such as supramolecular chemistry, nanochemistry and molecular magnetism. The third section is devoted to POM-based materials and their applications and prospects in catalysis and materials science.

MICHAEL T. POPE AND ACHIM MULLER Department of Chemistry, Georgetown University, Washington, DC 20057-2222, U.S.A.; Department of Chemistry, University of Bielefeld, D-4BOO Bielefeld 1, F.R.G. Polyoxometalates, from their discovery and early development in the final decades of the 19th century to their current significance in disciplines as diverse as chemistry, mathematics, and medicine, continue to display surprisingly novel structures, unexpected reactivities and applications, and to attract increasing attention worldwide. Most of the contributors to the present volume participated in the workshop held at the Center for Interdisciplinary Research at the University of Bielefeld, July 15-17, 1992. The choice of topics illustrates some of the variety of directions and fields in which polyoxometalates can play an important role. Although many of the leading polyoxometalate research groups are represented here, we regret that time constraints, financial limitations, and in some cases difficulties of communication did not allow us to include significant and imp- tant work from other groups outside Europe and North America. In the following we briefly review the current status of the field of po- oxometalates.

Well-researched reference on stable alternative electrocatalysts and electrode materials with the potential to transform chemistry and processes in sensor and energy related technologies Applied Polyoxometalate-Based Electrocatalysis delivers an overview of the variety of efficient applications of free POM and POM-based (nano)composites as exciting materials in the field of electrocatalysis. With a variety of sizes, shapes, composition, and physical and chemical properties, these composites have important properties, such as the ability to undergo reversible multivalence reductions/oxidations, leading to the formation of mixed-valence species, which brings about favorable electrocatalytic properties with regard to several electrochemical processes. Written by a highly qualified independent researcher internationally recognized for her contributions to materials for electrochemical energy-related reactions, Applied Polyoxometalate-Based Electrocatalysis includes information on: General methodologies used in the preparation of free POMs and POM-based nanocomposites and different strategies employed in electrode modification Role of POM-modified electrodes in oxidative and reductive electrocatalysis, including the detection/sensing of several (bio)molecules of interest and carbon dioxide electroreduction Application of POM-based (nano)composites, including the oxygen reduction reaction relevant to fuel cells, the oxygen and hydrogen evolution reactions, and batteries and supercapacitors Applied Polyoxometalate-Based Electrocatalysis is an essential reference on the subject for chemists, material scientists, chemical engineers, and institutions involved in work related to free POM and POM-based (nano)composites.

Polyoxometalate-Based Hybrids and their Applications focuses on recent progress in polyoxometalate-based hybrids materials. Chapters present the structure, composition, classification and properties of POMs such as isopolyaions, heteropolyanions, giant and lacunary polyoxometalates and then cover polyoxometalate-based open-frameworks (POM-OFs), include a historical introduction to these compounds, and present their synthetic strategies. The structural diversity and relative applications of POM-OFs is also covered. Other sections delve into synthetic strategies, structural diversity and relative applications of porous polyoxometalate-based metal-organic frameworks. Polyoxometalate-based coordination polymers (POMCPs) and polyoxometalate-based host-guest framework materials are highlighted in final sections. This book is an essential reference for inorganic chemists, biochemists, and material scientists working in academia and industry. - Discusses polyoxometalate-based host-guest framework materials - Includes coverage of polyoxometalates and their environmental applications - Reviews transition metal substituted lacunary polyoxometalates

Polyoxometalates constitute an extensive class of compounds with an unmatched range of structures, properties and applications. This is an authoritative, up-to-date summary of the chemistry and applications of polyoxometalates.

The authors of this volume concentrate on the recent progress of novel polyoxometalate (POM) syntheses, as well as advances made in catalytic, electrochemical, and sensing systems. The state-of-the-art techniques such as flow system and gel-electrophoresis for the discovery of POMs are covered with a detailed discussion. Of particular importance, the application of POM-based materials in photo-sensing, heterogeneous catalysis, energy conservation and storage, and gas separation is reviewed. Over the past few years, POM chemistry has witnessed a remarkable progress with more than 1500 papers published each year. Due to their intrinsic structural features, POMs are considered as versatile building blocks for the construction of sophisticated complex assemblies and advanced multi-functional materials. Various strategies, methods, and techniques have been adopted to develop POM-based materials with intriguing properties and excellent performance. All the contributors to this volume are young, vibrant chemists in this research field and all the works are carefully collected from the authors’ years of experience. This volume serves as an essential reference for every POM chemist and is of great interest to new researchers who wish to learn more about this area.

The book attempts to make available the recent developments in polyoxometalate (POM) synthesis. The focus centralises on the functionalisation of POMs with covalently organic moiety (for instance, the use of exogenous ligands such as carboxylate or bisphosphonate). It also delves into the development of lanthanide POMs, or the formation of blackberry-like assemblies. Likewise, the properties (redox properties, magnetism, etc...), and its applications (homogeneous and heterogeneous catalysis, photocatalysis, photoelectrocatalysis and photovoltaic cell development, etc.) are also analysed. This application concerns also the catalysis of H2O oxidation, photodegradation of pollutants, and reduction of cationic metal to form original nanoparticles. The use of polyoxometalates as catalysts for biologically relevant reactions is also considered. One of the other aims of the book is to highlight some recent developments and perspectives in the domain of materials and their applications. For instance, the use of POM-organic photosensitiser hybrids can also be achieved for application in the generation of photocurrent and the development of new types of solar cells. By combining POMs with electrically active materials, a variety of applications have been explored and several examples of POM-based electronic materials are presented in this book.

The book highlights recent prominent results in the domain of the synthesis of new polyoxometalates with a specific attention to polyoxothioanions, and provides some novelties and perspectives in selected domains such as magnetism, luminescence and nanochemistry, and macroions self-assembly in solutions. The case of OC one-potOCO syntheses often used and reported in POMs synthesis is studied in terms of more complex solution speciation processes related to highly dynamical situation connected to factors such as pH, ionic strength, reaction time, temperature, counterion nature, concentration of starting materials, presence of electron donors and redox potentials. The behavior of macroions (2nm-6nm size range) in solution is shown to be quite different from the simple ionic solution or colloidal systems (DebyeOCoHuckel model). Their self-assembling into a single-layered, spherical, hollow vesicle structure, namely the OC blackberryOCO structure, is clearly described. Examples of spin clusters with tunable interactions are given and single molecule magnets based on POMs are specifically tackled. Besides paramagnetic transition metal centres and lanthanoid ions encapsulated in archetypal lacunary polyoxoanions, magnetically functionalized Kleperates are described, their discovery tracing back nearly 15 years.

"Chemists from several international polyoxometalate research groups discussed recent results, including: controlled self-organization processes for the preparation of nano-composites; electronic interactions in magnetic mixed-valence cryptands and coronands; synthesis of the novel polyoxometalates with topological or biological significance; systematic investigations in acid-base and/or redox catalysis for organic transformations; and electronic properties in materials science."--Page v