The oxynitrides are a group of inorganic compounds containing oxygen and nitrogen not bound to each other, instead combined with other non-metallic or metallic elements. Some of these are oxosalts with oxygen replaced by nitrogen. Some of these compounds do not have a fixed oxygen to nitrogen ratio, but instead form ceramics with a range of compositions. They are in the class of mixed anion compounds.
Many can be formed by heating an oxide or carbonate with ammonia. The hydrogen can assist by reducing some of the oxygen. With higher temperatures and pressures nitrogen can be heated with a mixed oxide to yield a product. [1] Other nitrogen rich compounds that can be heated with oxygen containing material are urea and melamine. For example urea heated with ammonium dihydrogen phosphate yields a phosphorus oxynitride.
There may not be a definite ratio of nitrogen to oxygen, and also nitrogen and oxygen may be disordered, swapping places at random.
Compared to oxides, the oxynitrides have a smaller band gap. [2]
| name | other name | formula | properties | reference |
|---|---|---|---|---|
| aluminium oxynitride | ALON | transparent, tough | ||
| Lithium silicon oxynitride | LiSiON | Pca21 Wurtzite structure a=5.1986 b=6.3893 c=4.7398 | [3] | |
| SiAlON | SiAlNO (Li,Mg,Y,Le,Ce,Eu) | |||
| Silicon oxynitride | ||||
| sodium silicon oxynitride | NaSiON | white Wurtzite structure | [3] | |
| Sinoite | Si2N2O | mineral | ||
| Li14Cr2N8O | P3 a=5.799 c=8.263 | [3] | ||
| NaGeON | white Wurtzite structure | [3] | ||
| potassium germanium oxynitride | KGeON | yellow Wurtzite structure a=5.7376 b=8.0535 c=5.2173 | [3] | |
| (Si,Ge)2N2O | [4] | |||
| CaTaO2N | perovskite | [1] | ||
| SrTaO2N | perovskite | [1] | ||
| BaTaO2N | perovskite | [1] | ||
| CaNbO2N | perovskite | [1] | ||
| SrNbO2N | perovskite | [1] | ||
| Sr2NbO3N | [1] | |||
| strontium gallium oxynitride | Sr4GaN3O | red Pbca a = 7.4002 b = 24.3378 c = 7.4038Å, Z = 8 | [5] | |
| Sr3Nb2O5N2 | [1] | |||
| In32ON17F43 | Ia3 a=10.536 fluorite structure | |||
| BaNbO2N | perovskite | [1] | ||
| LaTaON2 | [1] | |||
| LnTiO2N | [1] | |||
| LnTaO2N | [1] | |||
| EuTaO2N | [1] | |||
| EuNbO2N | [1] | |||
| LnNbO2N | [1] | |||
| LnVO2N | [1] | |||
| CaTiO2N | [1] | |||
| CaZrO2N | [1] | |||
| LaZrO2N | [1] | |||
| EuWON2 | [1] | |||
| Ln2AlO3N | [1] | |||
| PON | PNO | α-quartz, β-cristobalite, or moganite structure | ||
| Titanium nickel oxynitride | NiTiNO | |||
| Chromium oxynitride | Cr(N,O) | |||
| galloaluminophosphate oxynitride | AlGaPON | [6] | ||
| zinc oxynitride | ZnON | |||
| Titanium oxynitride | TiOxNy | [7] | ||
| K2Ca2Ta3O9N·2H2O | perovskite | [2] | ||
| K2LaTa2O6N·1.6H2O | [2] |
Iron nitrides are inorganic chemical compounds of iron and nitrogen.
The borate carbonates are mixed anion compounds containing both borate and carbonate ions. Compared to mixed anion compounds containing halides, these are quite rare. They are hard to make, requiring higher temperatures, which are likely to decompose carbonate to carbon dioxide. The reason for the difficulty of formation is that when entering a crystal lattice, the anions have to be correctly located, and correctly oriented. They are also known as borocarbonates. Although these compounds have been termed carboborate, that word also refers to the C=B=C5− anion, or CB11H12− anion. This last anion should be called 1-carba-closo-dodecaborate or monocarba-closo-dodecaborate.
An oxyhydride is a mixed anion compound containing both oxide O2− and hydride ions H−. These compounds may be unexpected as the hydrogen and oxygen could be expected to react to form water. But if the metals making up the anions are electropositive enough, and the conditions are reducing enough, solid materials can be made that combine hydrogen and oxygen in the negative ion role.
A hydridonitride is a chemical compound that contains hydride and nitride ions in a single phase. These inorganic compounds are distinct from inorganic amides and imides as the hydrogen does not share a bond with nitrogen, and contain a larger proportion of metals.
The inorganic imides are compounds containing an ion composed of nitrogen bonded to hydrogen with formula HN2−. Organic imides have the NH group, and two single or one double covalent bond to other atoms. The imides are related to the inorganic amides (H2N−), the nitrides (N3−) and the nitridohydrides (N3−•H−).
The iodate fluorides are chemical compounds which contain both iodate and fluoride anions (IO3− and F−). In these compounds fluorine is not bound to iodine as it is in fluoroiodates.
The telluride oxides or oxytellurides are double salts that contain both telluride and oxide anions. They are in the class of mixed anion compounds.
A selenite fluoride is a chemical compound or salt that contains fluoride and selenite anions. These are mixed anion compounds. Some have third anions, including nitrate, molybdate, oxalate, selenate, silicate and tellurate.
The nitridosilicates are chemical compounds that have anions with nitrogen bound to silicon. Counter cations that balance the electric charge are mostly electropositive metals from the alkali metals, alkaline earths or rare earth elements. Silicon and nitrogen have similar electronegativities, so the bond between them is covalent. Nitrogen atoms are arranged around a silicon atom in a tetrahedral arrangement.
The oxonitridosilicates, also called sions or silicon-oxynitrides are inorganic ceramic compounds in which oxygen and nitrogen atoms are bound to a silicon atom. A common variant also has aluminium replacing some silicon. They can be considered as silicates in which nitrogen partially replaces oxygen, or as nitridosilicates with oxygen partly replacing nitrogen.
The borosulfates are heteropoly anion compounds which have sulfate groups attached to boron atoms. Other possible terms are sulfatoborates or boron-sulfur oxides. The ratio of sulfate to borate reflects the degree of condensation. With [B(SO4)4]5- there is no condensation, each ion stands alone. In [B(SO4)3]3- the anions are linked into a chain, a chain of loops, or as [B2(SO4)6]6− in a cycle. Finally in [B(SO4)2]− the sulfate and borate tetrahedra are all linked into a two or three-dimensional network. These arrangements of oxygen around boron and sulfur can have forms resembling silicates. The first borosulfate to be discovered was K5[B(SO4)4] in 2012.
The borotellurates are heteropoly anion compounds which have tellurate groups attached to boron atoms. The ratio of tellurate to borate reflects the degree of condensation. In [TeO4(BO3)2]8- the anions are linked into a chain. In [TeO2(BO3)4]10− the structure is zero dimensional with isolated anions. These arrangements of oxygen around boron and tellurium can have forms resembling silicates. The first borotellurate to be discovered was the mixed sodium rare earth compounds in 2015.
The boroselenites are heteropoly anion chemical compounds containing selenite and borate groups linked by common oxygen atoms. They are not to be confused with the boroselenates with have a higher oxidation state for selenium, and extra oxygen. If selenium is replaced by sulfur, it would be a borosulfite. Boroselenites are distinct from selenoborates in which selenium replaces oxygen in borate, or perselenoborates which contain Se-Se bonds as well as Se-B bonds. The metal boroselenites were only discovered in 2012.
Borate sulfides are chemical mixed anion compounds that contain any kind of borate and sulfide ions. They are distinct from thioborates in which sulfur atoms replace oxygen in borates. There are also analogous borate selenides, with selenium ions instead of sulfur.
The borate bromides are mixed anion compounds that contain borate and bromide anions. They are in the borate halide family of compounds which also includes borate fluorides, borate chlorides, and borate iodides.
The borate iodides are mixed anion compounds that contain both borate and iodide anions. They are in the borate halide family of compounds which also includes borate fluorides, borate chlorides, and borate bromides.
Selenide borates, officially known as borate selenides, are chemical mixed anion compounds that contain any kind of borate and selenide ions. They are distinct from selenoborates in which selenium atoms replace oxygen in borates. There are also analogous borate sulfides, with sulfur ions instead of selenium.
Sulfidostannates, or thiostannates are chemical compounds containing anions composed of tin linked with sulfur. They can be considered as stannates with sulfur substituting for oxygen. Related compounds include the thiosilicates, and thiogermannates, and by varying the chalcogen: selenostannates, and tellurostannates. Oxothiostannates have oxygen in addition to sulfur. Thiostannates can be classed as chalcogenidometalates, thiometallates, chalcogenidotetrelates, thiotetrelates, and chalcogenidostannates. Tin is almost always in the +4 oxidation state in thiostannates, although a couple of mixed sulfides in the +2 state are known,
Caesium sesquioxide is a chemical compound with the formula Cs2O3 or Cs4O6. In terms of oxidation states, Caesium in this compound has a nominal charge of +1, and the oxygen is a mixed peroxide (O22-) and superoxide (O2−) for a structural formula of (Cs+)4(O2−)2(O22-). 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.
Arsenidosilicates are chemical compounds that contain anions with arsenic bonded to silicon. They are in the category of tetrelarsenides, pnictidosilicates, or tetrelpnictides. They can be classed as Zintl phases or intermetallics. They are analogous to the nitridosilicates, phosphidosilicates, arsenidogermanates, and arsenidostannates. They are distinct from arsenate silicates which have oxygen connected with arsenic and silicon, or arsenatosilicates with arsenate groups sharing oxygen with silicate.