The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table. All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic properties. Indeed, the alkali metals provide the best example of group trends in properties in the periodic table, with elements exhibiting well-characterised homologous behaviour. This family of elements is also known as the lithium family after its leading element.
In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula O−2. The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature. Molecular oxygen (dioxygen) is a diradical containing two unpaired electrons, and superoxide results from the addition of an electron which fills one of the two degenerate molecular orbitals, leaving a charged ionic species with a single unpaired electron and a net negative charge of −1. Both dioxygen and the superoxide anion are free radicals that exhibit paramagnetism. Superoxide was historically also known as "hyperoxide".
Sodium amide, commonly called sodamide, is the inorganic compound with the formula NaNH2. It is a salt composed of the sodium cation and the azanide anion. This solid, which is dangerously reactive toward water, is white, but commercial samples are typically gray due to the presence of small quantities of metallic iron from the manufacturing process. Such impurities do not usually affect the utility of the reagent. NaNH2 conducts electricity in the fused state, its conductance being similar to that of NaOH in a similar state. NaNH2 has been widely employed as a strong base in organic synthesis.
Cuprates are a class of compounds that contain copper (Cu) atom(s) in an anion. They can be broadly categorized into two main types:
Oxygen fluorides are compounds of elements oxygen and fluorine with the general formula OnF2, where n = 1 to 6. Many different oxygen fluorides are known:
Potassium superoxide is an inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide anion. It is used as a CO2 scrubber, H2O dehumidifier, and O2 generator in rebreathers, spacecraft, submarines, and spacesuits.
Sodium peroxide is an inorganic compound with the formula Na2O2. This yellowish solid is the product of sodium ignited in excess oxygen. It is a strong base. This metal peroxide exists in several hydrates and peroxyhydrates including Na2O2·2H2O2·4H2O, Na2O2·2H2O, Na2O2·2H2O2, and Na2O2·8H2O. The octahydrate, which is simple to prepare, is white, in contrast to the anhydrous material.
Ozonide is the polyatomic anion O−3. Cyclic organic compounds formed by the addition of ozone to an alkene are also called ozonides.
A solvated electron is a free electron in a solution, in which it behaves like an anion. An electron's being solvated in a solution means it is bound by the solution. The notation for a solvated electron in formulas of chemical reactions is "e−". Often, discussions of solvated electrons focus on their solutions in ammonia, which are stable for days, but solvated electrons also occur in water and many other solvents – in fact, in any solvent that mediates outer-sphere electron transfer. The solvated electron is responsible for a great deal of radiation chemistry.
Lithium superoxide is an unstable inorganic salt with formula LiO2. A radical compound, it can be produced at low temperature in matrix isolation experiments, or in certain nonpolar, non-protic solvents. Lithium superoxide is also a transient species during the reduction of oxygen in a lithium–air galvanic cell, and serves as a main constraint on possible solvents for such a battery. For this reason, it has been investigated thoroughly using a variety of methods, both theoretical and spectroscopic.
Bromous acid is the inorganic compound with the formula of HBrO2. It is an unstable compound, although salts of its conjugate base – bromites – have been isolated. In acidic solution, bromites decompose to bromine.
Copper peroxide is a hypothetical inorganic compound with the chemical formula CuO2. The 1:2 ratio of copper and oxygen would be consistent with copper in its common +2 oxidation state and a peroxide group. Although samples of this composition have not been isolated, CuO2 has attracted interest from computational perspective. One highly cited analysis concludes that gaseous CuO2 is a superoxide, with copper in a +1 oxidation state: Cu+O−2.
Metal peroxides are metal-containing compounds with ionically- or covalently-bonded peroxide (O2−
2) groups. This large family of compounds can be divided into ionic and covalent peroxide. The first class mostly contains the peroxides of the alkali and alkaline earth metals whereas the covalent peroxides are represented by such compounds as hydrogen peroxide and peroxymonosulfuric acid (H2SO5). In contrast to the purely ionic character of alkali metal peroxides, peroxides of transition metals have a more covalent character.
Rubidium superoxide or rubidium hyperoxide is a chemical compound with the chemical formula RbO2. In terms of oxidation states, the negatively charged superoxide and positively charged rubidium give it a structural formula of Rb+[O2]−.
Caesium peroxide or cesium peroxide is an inorganic compound of caesium and oxygen with the chemical formula Cs2O2. It can be formed from caesium metal by adding a stoichiometric amount in ammonia solution, or oxidizing the solid metal directly.
Rubidium ozonide is an oxygen rich compound of rubidium. It is an ozonide, meaning it contains the ozonide anion (O3−).
Potassium ozonide is an oxygen rich compound of potassium. It is an ozonide, meaning it contains the ozonide anion (O3−). In polarized light, it shows pleochroism. Hybrid functional calculations have predicted the compound is an insulator with a band gap of 3.0 eV, and has magnetic behavior which departs from the Curie–Weiss law.
Sodium ozonide (NaO3) is an oxygen-rich compound of sodium. As an ozonide, it contains the ozonide anion (O3−).
Caesium sesquioxide is a chemical compound with the formula Cs2O3 or more accurately Cs4O6. It is an oxide of caesium containing oxygen in different oxidation states. It consists of caesium cations Cs+, superoxide anions O−2 and peroxide anions O2−2. Caesium in this compound has an oxidation state of +1, while oxygen in superoxide has an oxidation state of −1/2 and oxygen in peroxide has an oxidation state of −1. This compound has a structural formula of (Cs+)4(O−2)2(O2−2). Compared to the other caesium oxides, this phase is less well studied, but has been long present in the literature. It can be created by thermal decomposition of caesium superoxide at 290 °C.
Caesium superoxide is a chemical compound with the chemical formula CsO2. It consists of caesium cations Cs+ and superoxide anions O−2. It is an orange solid.
