It has been a decade since two seminal reviews demonstrated that mixed-valence compounds share many unique and fascinating features. The insight pro vided by those early works has promoted a great deal of both experimental and theoretical study. As a result of extensive efforts, our understanding of the bonding and properties of mixed-valence compounds has advanced substantially. There has been no compre hensive treatment of mixed-valence compounds since 1967, and the meeting convened at Oxford in September, 1979, provided a unique opportunity to examine the subject and its many ramifications. Mixed-valence compounds play an important role in many fields. Although the major impact of the subject has been in chemistry, its importance has become increasingly clear in solid state physics, geology, and biology. Extensive interest and effort in the field of molecular metals has demonstrated that mixed-valency is a prerequisite for high elec trical conductivity. The intense colors of many minerals have been shown to be due to mixed-valency, and the electron-transfer properties of certain mixed-valence metalloproteins are important in biological processes. Experts from all of these areas participated in this meeting, and the truly interdisciplinary nature of the subject made it a unique learning experience for all in attendance.

Inhalt
I. An Overview of Mixed-Valency.- to Mixed-Valence Chemistry.- Descriptive Chemistry of Mixed-Valence Compounds.- Synthetic Approaches to Mixed-Valence Chemistry.- II. Models for the Mixed-Valence State.- Electron Transfer in Mixed-Valence Compounds.- A Vibronic Coupling Model for Mixed-Valence Compounds and its Application to Real Systems.- Electron Delocalization, Structure and Dynamics in Mixed-Valence Systems.- III. Experimental Probes to Mixed-Valence Compounds.- Magnetism of Mixed-Valence Compounds.- Applications of the Mössbauer Effect to the Study of Mixed-Valence Compounds.- Electronic, Raman, and Resonance-Raman Spectroscopic Studies of Mixed-Valence Complexes.- IV. Classes of Mixed-Valence Materials.- Mixed-Valence Minerals of Iron and Titanium: Correlations of Structural, Mössbauer and Electronic Spectral Data.- Mixed-Valency in Discrete and Condensed Transition Metal Cluster Species With Classical Ligands.- Heteropoly Blues.- Linear Chain Mixed-Valence Systems with Direct Metal-Metal Interactions.- The Verwey Transition Revisited.- Polymetallic Centers in Biology.- Mixed-Valence in the Organic Solid State.- Photoelectron Spectroscopy of Mixed-Valence Compounds.- List of Contribution to the Discussion Sessions.