Mixed-anion compounds, heteroanionic materials or mixed-anion materials are chemical compounds containing cations and more than one kind of anion. The compounds contain a single phase, rather than just a mixture. [1] [2]
By having more than one anion, many more compounds can be made, and properties tuned to desirable values. [3] In terms of optics, properties include phosphorescence, photocatalysis, [4] laser damage threshold, refractive index, birefringence, absorption particularly in the ultraviolet or near infrared, non-linearity. [5] Mechanical properties can include ability to grow a large crystal, ability to form a thin layer, strength, or brittleness.
Thermal properties can include melting point, thermal stability, phase transition temperatures, thermal expansion coefficient.
For electrical properties, electric conductivity, band gap, superconducting transition temperature piezoelectricity, pyroelectricity, ferromagnetism, dielectric constant, charge-density wave transition can be adjusted.
Many of the non-metals that could make mixed-anion compounds may have greatly varying volatilities. This makes it more difficult to combine the elements together. Compounds may be produced in a solid state reaction, by heating solids together, either in a vacuum or a gas. Common gases used include, oxygen, hydrogen, ammonia, chlorine, fluorine, hydrogen sulfide, or carbon disulfide. Soft chemical approaches to manufacture include solvothermal synthesis, or substituting atoms in a structure by others, including by water, oxygen, fluorine, or nitrogen. Teflon pouches can be used to separate different formulations. Thin film deposits can yield strained layers. High pressures can be used to prevent evaporation of volatiles. High pressure can result in different crystal forms, perhaps with higher coordination number. [1]
H | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
B | BH | B | |||||||||||||||
C | CH | CB | C | ||||||||||||||
N | NH | NB | NC | N | |||||||||||||
O | OH | OB | OC | ON | O | ||||||||||||
F | FH | FB | FC | FN | FO | F | |||||||||||
Si | SiH | SiB | SiC | SiN | SiO | SiF | Si | ||||||||||
P | PH | PB | PC | PN | PO | PF | PSi | P | |||||||||
S | SH | SB | SC | SN | SO | SF | SSi | SP | S | ||||||||
Cl | ClH | ClB | ClC | ClN | ClO | ClF | ClSi | ClP | ClS | Cl | |||||||
Ge | GeH | GeB | GeC | GeN | GeO | GeF | GeSi | GeP | GeS | GeCl | Ge | ||||||
As | AsH | AsB | AsC | AsN | AsO | AsF | AsSi | AsP | AsS | AsCl | AsGe | As | |||||
Se | SeH | SeB | SeC | SeN | SeO | SeF | SeSi | SeP | SeS | SeCl | SeGe | SeAs | Se | ||||
Br | BrH | BrB | BrC | BrN | BrO | BrF | BrSi | BrP | BrS | BrCl | BrGe | BrAs | BrSe | Br | |||
Sb | SbH | SbB | SbC | SbN | SbO | SbF | SbSi | SbP | SbS | SbCl | SbGe | SbAs | SbSe | SbBr | Sb | ||
Te | TeH | TeB | TeC | TeN | TeO | TeF | TeSi | TeP | TeS | TeCl | TeGe | TeAs | TeSe | TeBr | TeSb | Te | |
I | IH | IB | IC | IN | IO | IF | ISi | IP | IS | ICl | IGe | IAs | ISe | IBr | ISb | ITe | I |
Bi | BiH | BiB | BiC | BiN | BiO | BiF | BiSi | BiP | BiS | BiCl | BiGe | BiAs | BiSe | BiBr | BiSb | BiTe | BiI |
Some elements can form several kinds of anions, and compounds may exist with more than one. Examples include the iodate periodates, [10] sulfite sulfates, selenate selenites, tellurite tellurates, nitrate nitrites, phosphate phosphites, and arsenate arsenites.
These kinds also include different oligomeric forms such as phosphates or fluorotitanates, such as [Ti4F20]4- and [TiF5]−. [11]
Bisulfide is an inorganic anion with the chemical formula HS−. It contributes no color to bisulfide salts, and its salts may have a distinctive putrid smell. It is a strong base. Bisulfide solutions are corrosive and attack the skin.
Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.
Ionic radius, rion, is the radius of a monatomic ion in an ionic crystal structure. Although neither atoms nor ions have sharp boundaries, they are treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice. Ionic radii are typically given in units of either picometers (pm) or angstroms (Å), with 1 Å = 100 pm. Typical values range from 31 pm (0.3 Å) to over 200 pm (2 Å).
A chalcogenide is a chemical compound consisting of at least one chalcogen anion and at least one more electropositive element. Although all group 16 elements of the periodic table are defined as chalcogens, the term chalcogenide is more commonly reserved for sulfides, selenides, tellurides, and polonides, rather than oxides. Many metal ores exist as chalcogenides. Photoconductive chalcogenide glasses are used in xerography. Some pigments and catalysts are also based on chalcogenides. The metal dichalcogenide MoS2 is a common solid lubricant.
In chemical nomenclature, the IUPAC nomenclature of inorganic chemistry is a systematic method of naming inorganic chemical compounds, as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in Nomenclature of Inorganic Chemistry. Ideally, every inorganic compound should have a name from which an unambiguous formula can be determined. There is also an IUPAC nomenclature of organic chemistry.
Cadmium iodide is an inorganic compound with the formula CdI2. It is a white hygroscopic solid. It also can be obtained as a mono- and tetrahydrate. It has few applications. It is notable for its crystal structure, which is typical for compounds of the form MX2 with strong polarization effects.
Magnesium compounds are compounds formed by the element magnesium (Mg). These compounds are important to industry and biology, including magnesium carbonate, magnesium chloride, magnesium citrate, magnesium hydroxide, magnesium oxide, magnesium sulfate, and magnesium sulfate heptahydrate.
The chemical state of a chemical element is due to its electronic, chemical and physical properties as it exists in combination with itself or a group of one or more other elements. A chemical state is often defined as an "oxidation state" when referring to metal cations. When referring to organic materials, a chemical state is usually defined as a chemical group, which is a group of several elements bonded together. Material scientists, solid state physicists, analytical chemists, surface scientists and spectroscopists describe or characterize the chemical, physical and/or electronic nature of the surface or the bulk regions of a material as having or existing as one or more chemical states.
The thallium halides include monohalides, where thallium has oxidation state +1, trihalides in which thallium generally has oxidation state +3, and some intermediate halides containing thallium with mixed +1 and +3 oxidation states. These salts find use in specialized optical settings, such as focusing elements in research spectrophotometers. Compared to the more common zinc selenide-based optics, materials such as thallium bromoiodide enable transmission at longer wavelengths. In the infrared, this allows for measurements as low as 350 cm−1 (28 μm), whereas zinc selenide is opaque by 21.5 μm, and ZnSe optics are generally only usable to 650 cm−1 (15 μm).
In chemistry, an ate complex is a salt formed by the reaction of a Lewis acid with a Lewis base whereby the central atom increases its valence and gains a negative formal charge..
Nickel–Strunz classification is a scheme for categorizing minerals based upon their chemical composition, introduced by German mineralogist Karl Hugo Strunz in his Mineralogische Tabellen (1941). The 4th and the 5th edition was also edited by Christel Tennyson (1966). It was followed by A.S. Povarennykh with a modified classification.
Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions.
Many compounds of thorium are known: this is because thorium and uranium are the most stable and accessible actinides and are the only actinides that can be studied safely and legally in bulk in a normal laboratory. As such, they have the best-known chemistry of the actinides, along with that of plutonium, as the self-heating and radiation from them is not enough to cause radiolysis of chemical bonds as it is for the other actinides. While the later actinides from americium onwards are predominantly trivalent and behave more similarly to the corresponding lanthanides, as one would expect from periodic trends, the early actinides up to plutonium have relativistically destabilised and hence delocalised 5f and 6d electrons that participate in chemistry in a similar way to the early transition metals of group 3 through 8: thus, all their valence electrons can participate in chemical reactions, although this is not common for neptunium and plutonium.
The selenide iodides are chemical compounds that contain both selenide ions (Se2−) and iodide ions (I−) and one or metal atoms. They are in the class of mixed anion compounds or chalcogenide halides.
The telluride iodides are chemical compounds that contain both telluride ions (Te2−) and iodide ions (I−). They are in the class of mixed anion compounds or chalcogenide halides.
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.
Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl3, Eu(NO3)3 and Eu(CH3COO)3. Compounds with europium in the +2 oxidation state are also known. The +2 ion of europium is the most stable divalent ion of lanthanide metals in aqueous solution. Many europium compounds fluoresce under ultraviolet light due to the excitation of electrons to higher energy levels. Lipophilic europium complexes often feature acetylacetonate-like ligands, e.g., Eufod.
Terbium compounds are compounds formed by the lanthanide metal terbium (Tb). Terbium generally exhibits the +3 oxidation state in these compounds, such as in TbCl3, Tb(NO3)3 and Tb(CH3COO)3. Compounds with terbium in the +4 oxidation state are also known, such as TbO2 and BaTbF6. Terbium can also form compounds in the 0, +1 and +2 oxidation states.
Protactinium compounds are compounds containing the element protactinium. These compounds usually have protactinium in the +5 oxidation state, although these compounds can also exist in the +2, +3 and +4 oxidation states.