Oxybismuthides or bismuthide oxides are chemical compounds formally containing the group BiO, with one

bismuth Bismuth is a chemical element; it has symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs nat ...

and one

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

atom. The bismuth and oxygen are not bound together as in

bismuthate Bismuthate is an ion. Its chemical formula is . It has bismuth in its +5 oxidation state. It is a very strong oxidizing agent. It reacts with hot water to make bismuth(III) oxide and oxygen. It also reacts with acids. Sodium bismuthate is the mos ...

s, instead they make a separate presence bound to the cations (metals), and could be considered as a mixed

bismuthide The bismuthide ion is but the term is often used to describe less reduced forms of bismuth. Bismuthides are compounds of bismuth with more electropositive elements. A wide variety are known. The stoichiometry of bismuthides ranges from lithi ...

oxide An oxide () is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion (anion bearing a net charge of −2) of oxygen, an O2− ion with oxygen in the oxidation st ...

compound. So a compound with O_mBi_n requires

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

s to balance a negative charge of 2m+3n. The cations will have charges of +2 or +3. The trications are often

rare earth element The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), are a set o ...

s or

actinide The actinide () or actinoid () series encompasses at least the 14 metallic chemical elements in the 5f series, with atomic numbers from 89 to 102, actinium through nobelium. Number 103, lawrencium, is also generally included despite being part ...

s. They are in the category of

oxypnictide In chemistry, oxypnictides are a class of materials composed of oxygen, a pnictogen (group-V, especially phosphorus and arsenic) and one or more other elements. Although this group of compounds has been recognized since 1995, interest in these com ...

compounds. Many of the bismuthide oxides have bismuth in an unusual −2 oxidation state. The ones with Ln₂BiO₂ have the anti-ThCr₂Si₂ structure. They include alternating layers of LnO ( anti-fluorite-type) and LnBiO. The Eu₄Bi₂O has an anti-K₂NiF₄ structure, the same as for Na₂Ti₂As₂O. Some other compounds contain calcium and a rare earth CaRE₃BiO₄, and Ca₂RE₈Bi₃O₁₀. Some of these compounds are superconductors at very low temperatures and many are semiconductors at standard conditions.

Examples

References

{{Bismuthides Bismuth compounds Bismuthides Oxides Mixed anion compounds