Iodate nitrates are mixed anion compounds that contain both iodate and nitrate anions.
Iodate nitrates can have high birefringence. The scandium salt has a giant birefringence of 0.348 at 546 nm. When discovered in 2021 it was a record high birefringence for oxyanion compounds, but it was exceeded by CeF2(SO4) just a month later with a value of 0.361 [1] and sodium hydrogen squarate hydrate, NaHC4O4·H2O with a value of 0.52 at 1064 nm. [2] All of these are beaten by hexagonal boron nitride (h-BN) with birefringence of 0.7 in visible light. [3]
| formula | name | formula weight | system | space group | cell Å | volume | density | comments | ref |
|---|---|---|---|---|---|---|---|---|---|
| Al(IO3)2NO3•6H2O | aluminium diiodate nitrate hexahydrate | hexagonal | P321 | a=6.764 c=8.09 Z=1 | [4] | ||||
| KIO3•KNO3•2HIO3 | dipotassium dihydrogen triiodate nitrate | orthorhombic | P212121 | a=7.109 b=10.638 c=15.5 | [5] | ||||
| Sc(IO3)2(NO3) | scandium diiodate nitrate | 1370.31 | trigonal | R32 | a=5.3536 c=23.567 Z=1 | 584.96 | 3.890 | colourless; giant birefringence 0.348 at 546 nm; SHG 4.0×KDP; UV edge 298 nm; stable to 360°C | [6] |
| In(IO3)2(NO3) | indium diiodate nitrate | 526.63 | trigonal | R32 | a=5.2165 c=24.195, γ=120° Z=3 | 570.2 | 4.601 | colourless | [7] |
| [In(IO3)(OH)(H2O)](NO3) | 386.75 | monoclinic | P21/n | a=5.5756 b=16.410 c=7.734, β=109.95 Z=4 | 665.2 | 3.862 | colourless | [7] | |
| La(IO3)2(NO3) | lanthanum diiodate nitrate | trigonal | P3121 | a=7.1002 c=38.177 Z=9 | SHG 0.6 × KDP; band gap 4.23 eV | [8] | |||
| Ce(IO3)2(NO3) | cerium diiodate nitrate | 551.93 | trigonal | P3121 | a=7.0537 c=37.972 Z=9 | 1639.8 | 5.030 | SHG 1 × KDP | [9] |
| α-Th(IO3)2(NO3)(OH) | triclinic | P1 | a=6.9581 b=7.2294 c=9.8989 α=68.896° β=88.759° γ=66.620° | [10] | |||||
| β-Th(IO3)2(NO3)(OH) | orthorhombic | Pbca | a=7.1459 b=14.140 c=16.612 | [10] |
Fluorooxoborate is one of a series of anions or salts that contain boron linked to both oxygen and fluorine. Several structures are possible, rings, or chains. They contain [BOxF4−x](x+1)− units BOF32− BO2F23−, or BO3F14−. In addition there can be borate BO3 triangles and BO4 tetrahedrons. These can then be linked by sharing oxygen atoms, and when they do that, the negative charge is reduced. They are distinct from the fluoroborates in which fluorine is bonded to the metals rather than the boron atoms. For example, KBBF, KBe2BO3F2 is a fluoroborate and has more fluorine and oxygen than can be accommodated by the boron atom.
The borate fluorides or fluoroborates are compounds containing borate or complex borate ions along with fluoride ions that form salts with cations such as metals. They are in the broader category of mixed anion compounds. They are not to be confused with tetrafluoroborates (BF4) or the fluorooxoborates which have fluorine bonded to boron.
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.
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.
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.
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 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. Over 75 unique compounds are known.
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.
The borate chlorides are chemical compounds that contain both borate ions and chloride ions. They are mixed anion compounds. Many of them are minerals. Those minerals that crystallise with water (hydrates) may be found in evaporite deposits formed when mineral water has dried out.
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.
Fluoride nitrates are mixed anion compounds that contain both fluoride ions and nitrate ions. Compounds are known for some amino acids and for some heavy elements. Some transition metal fluorido complexes that are nitrates are also known. There are also fluorido nitrato complex ions known in solution.
Selenogallates are chemical compounds which contain anionic units of selenium connected to gallium. They can be considered as gallates where selenium substitutes for oxygen. Similar compounds include the thiogallates and selenostannates. They are in the category of chalcogenotrielates or more broadly chalcogenometallates.
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 thiogermanates, 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,
Selenidogermanates are compounds with anions with selenium bound to germanium. They are analogous with germanates, thiogermanates, and telluridogermanates.
Sulfidogermanates or thiogermanates are chemical compounds containing anions with sulfur atoms bound to germanium. They are in the class of chalcogenidotetrelates. Related compounds include thiosilicates, thiostannates, selenidogermanates, telluridogermanates and selenidostannates.
Oxalate sulfates are mixed anion compounds containing oxalate and sulfate. They are mostly transparent, and any colour comes from the cations.
Selenite sulfates are mixed anion compounds containing both selenite (SeO3), and sulfate (SO4) anions.
A fluorooxoiodate or fluoroiodate is a chemical compound or ion derived from iodate, by substituting some of the oxygen by fluorine. They have iodine in the +5 oxidation state. The iodine atoms have a stereochemically active lone-pair of electrons. Many are non-centrosymmetric, and are second harmonic generators (SHG) of intense light shining through them. They are under investigation as materials for non-linear optics, such as for generating ultraviolet light from visible or infrared lasers.
Iodate sulfrates are mixed anion compounds that contain both iodate and sulfate anions. Iodate sulfates have been investigated as optical second harmonic generators, and for separation of rare earth elements. Related compounds include the iodate selenates and chromate iodates.
When values of birefingence are very high, the property is termed giant birefringence which more generically is called giant optical anisotropy. Values for giant birefringence exceed 0.3. Much bigger numbers are termed "colossal birefringence". These are achieved using nanostructures.