" Cluster Materials" is the fourth volume of the highly successful series " Advances in Metal and Semiconductor Clusters." In this volume the focus is on the properties of clusters which determine their potential applications as new materials. Metal and semiconductor clusters have been proposed as precursors for materials or as actual materials since the earliest days of cluster research. In the last few years, a variety of techniques have made it possible to produce clusters in sizes varying from a few atoms up to several thousand atoms. While some measurements are performed in the gas phase on non-isolated clusters, many cluster materials can now be isolated in macroscopic quantities and more convenient studies of their properties become possible.
In this volume the authors focus on measurement of optical, electronic, magnetic, chemical and mechanical properties of clusters or of cluster assemblies. All of these properties must fall into acceptable ranges of behaviour before useful materials composed of clusters can be put into practical applications. As evidenced by the various work described here, the realisation of practical products based on cluster materials seems to be approaching rapidly.

In previous volumes in this series, "Advances in Metal and Semiconductor Clusters," the focus has been on atomic clusters of metals, semiconductors and carbon. Fundamental gas phase studies have been surveyed, and most recently scientists have explored new materials which can be produced from clusters or cluster precursors. In this latest volume, the focus shifts to clusters composed primarily of non-metal molecules or atoms which have one or more metal atoms seeded into the cluster as an impurity. These clusters provide model systems for metal ion solvation processes and metal-ligand interactions.
Metal-ligand bonding underlies the vast fields of organometallic chemistry, transition metal chemistry and homogeneous catalysis. Catalytic activity, ligand displacement reactions and photochemical activity depend on the specific details of metal-ligand bonding. Likewise, metal ions are ubiquitous in chemistry and biology and weaker electrostatic interactions play a leading role in their function. In solution, metals exist in different charge states depending on the conditions, and the solvation environment strongly influences their chemistry. Many enzymes have metal ions at their active sites, and electrostatic interactions influence the selectivity for metal ion transport through cell membranes. Metal ions (e.g., Mg+, Ca+) are deposited into the earth's atmosphere by meteor ablation, resulting in a rich variety of atmospheric chemistry. Similarly, metal ions ( Mg+) have been observed in planetary atmospheres and in the impact of the comet Shoemaker-Levy 9 on Jupiter. In various circumstances, the electrostatic interactions of metal ions determine the outcome of significant chemistry. Cluster chemistry has made significant contributions to the understanding of these stronger metal ligand interactions and weaker metal ion solvation interactions. In this volume, the authors explore a variety of work in these general areas, where new cluster science techniques in the gas phase have made it possible to synthesize new kinds of complexes with metals and to measure their properties in detail.

"The Invitation" is a first-time collection of poems by author M.A. Duncan. Drawing on six decades of life's experiences, Duncan illuminates the pain of loss as she copes with death, divorce, cancer, infidelity and adoption. The Invitation exposes a woman's innermost feelings, richly extracted from personal journals which span many years.

Inside these poems is a clear, unobstructed view of the human heart, reproduced with insight, imagination and grace. Sincere, poignant, joyful and sad, the author communicates with common sense, carrying the reader safely along into the future.

Born in Hoboken and a lifelong resident of New Jersey, Duncan uses her home state as the setting for many of her narrative poems. Her long career in Real Estate, coupled with an intense passion for oil painting, solidifies and vividly colors the subject matter of her poetry.

Throughout "The Invitation," the author offers the reader a poetic understanding of her survival during some of life's most difficult challenges. Reading Duncan's poetry is as much about comfort as it is about feeling alive...