Thorium coordination: A comprehensive review based on coordination number

Although thorium comprises roughly 8.1 ppm of the Earth, its chemical characteristics and properties have been relatively underexplored. In large part due to its radioactivity and propensity to form oxides at pH above 5, thorium has been much less extensively investigated than first row transition metals. Today, there are close to 700,000 registered structures with an R-factor of 0.075 or better on the Cambridge Crystallographic Database, about 50% of which are complexes containing transition metals. The actinides make up roughly 8% of total number of database structures, with close to 85% of those being uranium containing complexes and 11% of the actinide structures containing thorium. Herein, we explore the various unique coordination environments of thorium with coordination numbers ranging from 5 to 12.