Metal carbonyl 18-electron complexes is sometimes catalysed by catalytic amounts of oxidants, via electron-transfer. Metal carbonyls react with reducing agents such as metallic sodium or sodium amalgam to give carbonylmetalate (or carbonylate) anions: For iron pentacarbonyl, one obtains the tetracarbonylferrate with loss of CO: Mercury can insert into the metal-metal bonds of some polynuclear metal carbonyls: The CO ligand is often susceptible to attack by nucleophiles. For example, trimethylamine oxide and bistrimethylsilylamide convert CO ligands to CO and CN, respectively. In the "Hieber base reaction", hydroxide ion attacks the CO ligand to give a metallacarboxylic acid, followed by the release of carbon
Alkali metal in lithium's thermonuclear properties increased sharply, the production of rubidium and caesium also increased correspondingly. Pure rubidium and caesium metals are produced by reducing their chlorides with calcium metal at 750 °C and low pressure. As a result of its extreme rarity in nature, most francium is synthesised in the nuclear reaction Au + O → Fr + 5 n, yielding francium-209, francium-210, and francium-211. The greatest quantity of francium ever assembled to date is about 300,000 neutral atoms, which were synthesised using the nuclear reaction given above. When the only natural isotope francium-223 is specifically required, it is produced