Structural Chemistry of Inorganic Actinide Compounds

Sergey Krivovichev, Peter Burns, Ivan Tananaev

• Publisher: Elsevier Science
• Year: 2006
• ISBN:
  9780080467917
• Topic: Physical Sciences
• Subtopic: Inorganic Chemistry

Structural Chemistry of Inorganic Actinide Compounds is a collection of 13 reviews on structural and coordination chemistry of actinide compounds. Within the last decade, these compounds have attracted considerable attention because of their importance for radioactive waste management, catalysis, ion-exchange and absorption applications, etc. Synthetic and natural actinide compounds are also of great environmental concern as they form as a result of alteration of spent nuclear fuel and radioactive waste under Earth surface conditions, during burn-up of nuclear fuel in reactors, represent oxidation products of uranium miles and mine tailings, etc. The actinide compounds are also of considerable interest to material scientists due to the unique electronic properties of actinides that give rise to interesting physical properties controlled by the structural architecture of respective compounds. The book provides both general overview and review of recent developments in the field, including such emergent topics as nanomaterials and nanoparticles and their relevance to the transfer of actinides under environmental conditions.* Covers over 2, 000 actinide compounds including materials, minerals and coordination polymers* Summarizes recent achievements in the field* Some chapters reveal (secret) advances made by the Soviet Union during the 'Cold war'

Chapter 1

Crystal chemistry of uranium oxocompounds: an overview

Peter C. Burns, Department of Civil Engineering and Geological Sciences, University of Notre Dame, Notre Dame, IN 46556 U.S.A.; Chemistry Division, Argonne National Laboratory, Argonne, IL, U.S.A.

Publisher Summary

This chapter discusses U⁶⁺ crystal chemistry in terms of the geometries of the coordination polyhedra and their linkages into extended structures. It is common for uranyl polyhedra to share their equatorial vertices with polyhedra containing other types of cations of higher valence. Where this is the case, the types of linkage are dependent upon both the size of the second polyhedron, and the charge of the central cation. The chapter examines the approaches to understanding and classifying structures containing U⁶⁺. With the substantial growth in the number of known structures containing uranyl polyhedra, a hierarchical arrangement of structures that facilitates comparison and that highlights underlying structural relationships is desirable. The goal of a structural hierarchy is to organize a wealth of complex and diverse structures into a cohesive framework. The chapter provides specific coverage for the structures of uranyl oxyhydrates, uranyl silicates, and uranyl carbonates.

1 Introduction

Crystals containing U⁶⁺ have been the focus of considerable research over several decades. The introduction of CCD-based detectors of X-rays and their application to crystal structure analysis [1] helped facilitate recent studies that have revealed many novel and fascinating crystal structures. A decade ago, the structures of about 180 inorganic compounds containing U⁶⁺ were known [2], and by 2006 the number of known structures has more than doubled [3]. The majority of these structures correspond to synthetic compounds, but about 90 are for minerals, the special subset of inorganic compounds that are stable for geological times, and that are consistent with geochemical conditions.

Current research concerning the crystal chemistry of U⁶⁺ oxocompounds is driven by the search for novel solids with important materials properties [4-10], as well as the importance of U⁶⁺ compounds in the environment [11-16], in geological U deposits [17], and in nuclear waste disposal [18]. The quantity of new structures becoming available is dramatically impacting the state of knowledge of the crystal chemistry of U⁶⁺. Relative to a decade ago, dramatically more is known about the structures of uranyl molybdates, sulfates, selenates, selenites, iodates, phosphates, arsenates, oxyhydrates, and peroxides, and significant advances have also been made in the cases of uranyl carbonates, chromates, and silicates. Many of the newer structures follow earlier-established trends, such as the dominance of layered structures, but recent research has also revealed the remarkable ability of U⁶⁺ structures t...

Table of contents

• Cover image
• Title page
• Table of Contents
• Foreword
• Preface
• Chapter 1: Crystal chemistry of uranium oxocompounds: an overview
• Chapter 2: Some features of stereochemistry of U(VI)
• Chapter 3: Hydrated oxides, hydroxides and peroxides of transuranium elements
• Chapter 4: Actinide compounds containing hexavalent cations of the VI group elements (S, Se, Mo, Cr, W)
• Chapter 5: Actinide compounds with heavy oxoanions containing a stereochemically active lone-pair of electrons
• Chapter 6: Crystal chemistry of actinide phosphates and arsenates
• Chapter 7: Structural chemistry of uranium vanadates: from 2-D to 3-D networks
• Chapter 8: Chemistry and structural chemistry of anhydrous tri- and tetravalent actinide orthophosphates
• Chapter 9: Structural chemistry of actinide polyoxometalates
• Chapter 10: Coordination interaction of transuranium elements with N-donor ligands
• Chapter 11: U(VI)-containing metal-organic frameworks and coordination polymers
• Chapter 12: Nanostructured actinide compounds: an introduction
• Chapter 13: Actinide host phases as radioactive waste forms
• Subject Index