Bi3+(aq) Bi(III) E0 ~ +2 V compounds often have stereochemically active lone pairs Factors favoring distorted geometries Low coordination numbers favor a stereochemically active lone pair – BiF3 and SnCl3- Lighter elements show a stronger tendency than their heavier relatives to be distorted – Sb > Bi Small ligands favor the presence of a distortion – F and alkoxides rather than I Lanthanide chemistry The lanthanides are technologically important Their chemistry is simple – dominated by the +3 oxidation state – the M3+ ions are hard Overview of lanthanide properties Applications of lanthanides They are widely used in ceramics synthesis – High Tc superconductors – Conducting oxide electrodes They are used in phosphors for devices such as TV sets They are used in lasers – Nd-YAG Compare oxidation states of the lanthanides and actinides The lanthanide contraction Separations Lanthanide ions are difficult to fully separate from one another using conventional chemical means as there sizes and charges are so similar – Can separate elements that readily do to +2 or +4 Liquid-liquid extraction used for large scale separation Ion exchange chromatography used when high purity is needed Complexes The lanthanides cations are all hard and form complexes with hard donor ligands The complexes often have high coordination numbers 6-10 and irregular geometries Ligands interact very weakly with the f-electons – Crystal field splitting is extremely small and often negligible Complexes have some applications including NMR shift reagents O O (CH3)3C CF2CF2CF3 fod Actinide chemistry Much more complicated than that of the rare earths The early actinides can attain a variety of oxidation states Overview of actinide properties Applications of actinide chemistry Nuclear fuel/ weapons material processing Nuclear fuel reprocessing Nuclear waste remediation Stable oxidation states of actinides Aqueous solution chemistry of the actinides The formation of oxo species is commonplace UO22+, UO2+ PuO22+, PuO2+ The nature of species present in solution is strongly dependent upon both pH and reduction potential Fission In a conventional nuclear reactor 235U nuclei capture neutrons.
Chemistry Explosives Overview Of Metal Chemistry by Angus Paul Wilkinson
by Mark
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