Fluorocarbonate

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An example of a fluorocarbonate: bastnasite from Zagi Mountain, Federally Administered Tribal Areas, Pakistan. Size: 1.5x1.5x0.3 cm. Bastnasite-(Ce)-177535.jpg
An example of a fluorocarbonate: bastnäsite from Zagi Mountain, Federally Administered Tribal Areas, Pakistan. Size: 1.5×1.5×0.3 cm.

A carbonate fluoride, fluoride carbonate, fluorocarbonate or fluocarbonate is a double salt containing both carbonate and fluoride. The salts are usually insoluble in water, and can have more than one kind of metal cation to make more complex compounds. Rare-earth fluorocarbonates are particularly important as ore minerals for the light rare-earth elements lanthanum, cerium and neodymium. Bastnäsite is the most important source of these elements. Other artificial compounds are under investigation as non-linear optical materials and for transparency in the ultraviolet, with effects over a dozen times greater than Potassium dideuterium phosphate. [1]

Contents

Related to this there are also chlorocarbonates and bromocarbonates. Along with these fluorocarbonates form the larger family of halocarbonates. In turn halocarbonates are a part of mixed anion materials. Compounds where fluorine connects to carbon making acids are unstable, fluoroformic acid decomposes to carbon dioxide and hydrogen fluoride, and trifluoromethyl alcohol also breaks up at room temperature. Trifluoromethoxide compounds exist but react with water to yield carbonyl fluoride.

Structures

MIMIIMIIIChargeCO3F
3311
1
11
11412
2
21521
1113
12
31622
41731
23
2115
12832
31917
321252
231353

The structure of the carbonate fluorides is mainly determined by the carbonate anion, as it is the biggest component. The overall structure depends on the ratio of carbonate to everything else, i.e. number (metals and fluorides)/number of carbonates. For ratios from 1.2 to 1.5 the carbonates are in a flat dense arrangement. From 1.5 to 2.3 the orientation is edge on. From 2.5 to 3.3 the arrangement is flat open. With a ratio from 4 to 11, the carbonate arrangement is flat-lacunar. [2]

The simplest formula is LnCO3F, where Ln has a 3+ charge.

For monocations there is A3CO3F, where A is a large ion such as K, Rb or Tl. [2]

For M = alkali metal, and Ln = lanthanide: MLnCO3F2 1:1:1:2; M3Ln(CO3)2F2 3:1:2:2; M2Ln(CO3)2F 2:1:2:1; M4Ln(CO3)2F3·H2O 4:1:2:3; M4Ln2(CO3)3F4 2:3:3:4. [2] M2Ln(CO3)F2 2:1:1:3.

For B = alkaline earth and Ln = lanthanide (a triple-charged ion) BLn(CO3)2F 1:1:2:1; BLn2(CO3)3F2 1:2:3:2 B2Ln3(CO3)5F3 2:3:5:3; B2Ln(CO3)2F3 2:1:2:3; B2Ln(CO3)F5 2:1:1:5 B2Ln(CO3)3F 2:1:3:1; B3Ln(CO3)F7 3:1:1:7; B3Ln2(CO3)5F2 3:2:5:2. [2]

For alkali with dication combinations: MB: MBCO3F MB3(CO3)2F3·H2O. [2]

For dications A and B there is ABCO3F2 with a degenerate case of A = B. [2]

KPb2(CO3)2F is layered. Each layer is like a sandwich, with lead and carbonate in the outer sublayers, and potassium and fluoride in the inner layer. K2.70Pb5.15(CO3)5F3 extends this structure with some of the layers also being a double-decker sandwich of carbonate, fluoride, carbonate, fluoride, carbonate. [3]

In the rare-earth fluorocarbonates the environment for the rare-earth atoms is 9-coordinated. Six oxygen atoms from carbonate are at the apices of a trigonal prism, and fluoride ions cap the rectangular faces of the prism. [4]

Formation

Carbonate fluoride compounds can be formed by a variety of related methods involving heating the precursor ingredients with or without water. Thallous fluoride carbonate was made simply by evaporating a fluoride thallium solution in ethanol and water in air. It absorbed sufficient carbon dioxide to yield the product. Most other carbonate fluorides are very insoluble and need high-temperature water to crystallise from. Supercritical water heated between 350 and 750 °C under pressures around 200 bars can be used. A sealed platinum tube can withstand the heat and pressure. Crystallisation takes about a day. With subcritical water around 200 °C, crystallisation takes about 2 days. This can happen in a teflon-coated pressure autoclave. The starting ingredients can be rare-earth fluorides and alkali carbonates. The high pressure is needed to keep the water liquid and the carbon dioxide under control, otherwise it would escape. If the fluoride levels are low, hydroxide can substitute for the fluoride. Solid-state reactions require even higher temperatures. [2]

Bastnäsite along with lukechangite (and petersenite) can be precipitated from a mixed solution of CeCl3, NaF, and NaOH with carbon dioxide. [5] Another way to make the simple rare-earth fluorocarbonates is to precipitate a rare-earth carbonate from a nitrate solution with ammonium bicarbonate and then add fluoride ions with hydrofluoric acid (HF). [6]

Pb2(CO3)F2 can be made by boiling a water solution of lead nitrate, sodium fluoride and potassium carbonate in a 2:2:1 molar ratio. [7]

Properties

structurecarbonate vibration, cm−1
ν1ν2ν3ν4
bastnäsite10868681443728
synchysite
parisite1079 10888701449734 746
KCdCO3F8531432
RbCdCO3F8431442

The visible spectrum of fluorocarbonates is determined mainly by the cations contained. Different structures only have slight effect on the absorption spectrum of rare-earth elements. [4] The visible spectrum of the rare-earth fluorocarbonates is almost entirely due to narrow absorption bands from neodymium. [4] In the near infrared around 1000 nm there are some absorption lines due to samarium and around 1547 nm are some absorption features due to praseodymium. Deeper into the infrared, bastnäsite has carbonate absorption lines at 2243, 2312 and 2324 nm. Parisite only has a very weak carbonate absorption at 2324 nm, and synchysite absorbs at 2337 nm. [4]

The infrared spectrum due to vibration of carbon–oxygen bonds in carbonate is affected by how many kinds of position there are for the carbonate ions. [4]

Reactions

An important chemical reaction used to prepare rare-earth elements from their ores, is to roast concentrated rare-earth fluorocarbonates with sulfuric acid at about 200 °C. This is then leached with water. This process liberates carbon dioxide and hydrofluoric acid and yields rare-earth sulfates:

2 LnCO3F + 3 H2SO4 → Ln2(SO4)3 + 2 HF + 2 H2O + 2 CO2.

Subsequent processing precipitates a double sulfate with sodium sulfate at about 50 °C. The aim is to separate out the rare-earth elements from calcium, aluminium, iron and thorium. [8]

At high enough temperatures the carbonate fluorides lose carbon dioxide, e.g.

KCu(CO3)F → CuO + KF + CO2

at 340 °C. [2]

The processing of bastnäsite is important, as it is the most commonly mined cerium mineral. When heated in air or oxygen at over 500 °C, bastnäsite oxidises and loses volatiles to form ceria (CeO2). Lukechangite also oxidises to ceria and sodium fluoride (NaF). Ce7O12 results when heated to over 1000 °C. [5]

2 Ce(CO3F) + O2 → 2 CeO2 + 2 CO2 + F2 [5]
Na3Ce2(CO3F)4F + 1/2 O2 → 2 CeO2 + 3 CO2 + NaF + Na2CO3 [5]

At 1300 °C Na2CO3 loses CO2, and between 1300 and 1600 °C NaF and Na2O boil off. [5]

When other rare-earth carbonate fluorides are heated, they lose carbon dioxide and form an oxyfluoride:

LaCO3F → LaOF + CO2 [9]

In some rare-earth extraction processes, the roasted ore is then extracted with hydrochloric acid to dissolve rare earths apart from cerium. Cerium is dissolved if the pH is under 0, and thorium is dissolved if it is under 2. [10]

KCdCO3F when heated yields cadmium oxide (CdO) and potassium fluoride (KF). [11]

When lanthanum fluorocarbonate is heated in a hydrogen sulfide, or carbon disulfide vapour around 500 °C, lanthanum fluorosulfide forms:

LaCO3F + 1/2 CO2 → LaSF + 1.5 CO2 [12]

Note that this also works for other lanthanides apart from cerium.

When lanthanum carbonate fluoride is heated at 1000 °C with alumina, lanthanum aluminate is produced: [13]

LaCO3F + 2 Al2O3 → LaAlO3 + CO2 + equiv AlOF

Within the hot part of the Earth's crust, rare-earth fluorocarbonates should react with apatite to form monazite. [14]

Minerals

Some rare-earth fluorocarbonate minerals exist. They make up most of the economic ores for light rare-earth elements (LREE). These probably result from hydrothermal liquids from granite that contained fluoride. [15] Rare-earth fluorocarbonate minerals can form in bauxite on carbonate rocks, as rare-earth fluoride complexes react with carbonate. [16] Carbonate fluoride compounds of rare-earth elements also occur in carbonatites. [17]

nameformulapatternformula weightcrystal systemspace groupunit cellvolumedensitycommentreferences
albrechtschraufite MgCa4(UO2)2(CO3)6F2⋅17–18H2O0:7:0:14:6:2triclinicP1a = 13.569, b = 13.419, c = 11.622 Å, α = 115.82, β = 107.61, γ = 92.84° Z=1774.62.69 [18]
aravaite Ba2Ca18(SiO4)6(PO4)3(CO3)F3OtrigonalR3ma = 7.1255, c = 66.290 Z=32914.8 [19]
arisite-(Ce) NaCe2(CO3)2[(CO3)1–xF2x]FPm2a=5.1109 c=8.6713 Z=1196.164.126dissolves in dilute HCl [20]
barentsite Na7AlH2(CO3)4F49:0:1:12:4:4505.95P1a=6.472 b=6.735 c=8.806 92.50 β=97.33 119.32
Bastnäsite (Ce, La)CO3F0:0:1:2:1:1P62ma=7.094 c=4.859
Bastnäsite-(La) La(CO3)F0:0:1:2:1:1217.91P62c
Bastnäsite-(Nd) Nd(CO3)F0:0:1:2:1:1223.25
Brenkite Ca2(CO3)F20:2:0:4:1:1178.16orthorhombicPbcna=7.650 b=7.550 c=6.548 [2]
Cebaite Ba3(Nd,Ce)2(CO3)5F20:3:2:12:5:2Monoclinica=21.42 b=5.087 c=13.30 β=94.8° [2] [21]
Cordylite = BaiyuneboiteNaBaCe2(CO3)4F1:1:2:9:4:1699.58P63/mmca=5.1011 c=23.096 [2]
Doverite CaY(CO3)2F0:1:1:5:2:1268.00 [22]
Francolite
Horvathite-Y (horváthite)NaY(CO3)F21:0:1:4:1:2209.90Pmcna=6.959 b=9.170 c=6.301
[23]
Huanghoite-(Ce) BaCe(CO3)2F0:1:1:5:2:1416.46TrigonalR3ma=5.072 c=38.46 [21] [2]
Kettnerite CaBi(CO3)OF
kukharenkoite-(Ce) Ba2Ce(CO3)3F0:2:1:7:3:1613.80P21/ma=13.365 b=5.097 c=6.638 β=106.45 [2]
Lukechangite-(Ce) Na3Ce2(CO3)4F3:0:2:9:4:1608.24P63/mmca=5.0612 c=22.820
lusernaite Y4Al(CO3)2(OH,F)11.6H2O0:0:5:15:2:11OrthorhombicPmnaa=7.8412 b=11.0313 c=11.3870 Z=2984.96
Mineevite-(Y) Na25BaY2(CO3)11(HCO3)4(SO4)2F2Cl2059.62 [24]
Montroyalite Sr4Al8(CO3)3(OH,F)26.10-11H2O [25]
Parisite [LaF]2Ca(CO3)30:1:2:8:3:2535.91RhombohedralR3a=7.124 c=84.1
Parisite-(Ce) [CeF]2Ca(CO3)30:1:2:8:3:2538.33monoclinicCca = 12.305 Å, b = 7.1056 Å, c = 28.2478 Å; β = 98.246°; Z = 12
Podlesnoite BaCa2(CO3)2F20:3:0:6:2:2375.50OrthorhombicCmcma = 12.511 b=5.857 c=9.446 Z=4692.23.614named after Aleksandr Semenovich Podlesnyi 1948 [26]
qaqarssukite-(Ce) BaCe(CO3)2F0:1:1:5:2:1416.46 [2]
röntgenite-(Ce) Ca2Ce3(CO3)5F30:2:3:13:5:3857.54R3a=7.131 c=69.40 [2]
rouvilleite Na3Ca2(CO3)3F3:2:0:7:3:1348.15Cca=8.012 b=15.79 c=7.019 β =100.78 [2]
Schröckingerite NaCa3(UO2)(CO3)3F(SO4)·10H2O1:6:13:3:1+888.49also with sulfate
Sheldrickite NaCa3(CO3)2F3·(H2O)1:3:0:7:2:3338.25Trigonala = 6.726 Å; c = 15.05 Å Z = 32.86 [27]
stenonite Sr2Al(CO3)F50:2:1:7:1:5357.22P21/na=5.450 b=8.704 c=13.150 β=98.72 [2]
Synchysite Ca(Ce,La)(CO3)2F0:1:1:5:2:1C2/ca=12.329 b=7.110 c=18.741 β=102.68 [2]
Thorbastnäsite CaTh(CO3)2F2.3H2OP2ca = 6.99, c = 9.71 z=3410.87brown [28]
zhonghuacerite Ba2Ce(CO3)3F0:2:1:7:3:1613.80Monoclinic [29]

Artificial

These are non-linear optical crystals in the AMCO3F family KSrCO3F KCaCO3F RbSrCO3F KCdCO3F CsPbCO3F RbPbCO3F RbMgCO3F KMgCO3F RbCdCO3F CsSrCO3F RbCaCO3F KZnCO3F CsCaCO3F RbZnCO3F [30]

formulanameweightcrystalspace groupunit cellvolumedensityUVthermal stabilitypropertiesreference
g/molÅÅ3nm°C
K2(HCO3)F·H2ODipotassium hydrogencarbonate fluoride monohydrate176.24monoclinicP 21/ma=5.4228 b=7.1572 c=7.4539 β=105.12 Z=2279.282.096transparent below 195 nm [31]
K3(CO3)F196.30R3ca=7.4181 c=16.3918 [2]
KLi2CO3F131.99HexagonalP63222a=4.8222 c=10.034 Z=2202.062.169190SHG; transparent [32]
KMgCO3F142.42HexagonalP62ma=8.8437 c=3.9254 z=3265.882.668200 [33]
Na3Ca2(CO3)3Frouvilleite348.16monoclinicCma=8.0892 b=15.900 c=3.5273 β=101.66 Z=2444.322.602190white [34]
KCaCO3F158.18HexagonalP6m2a=5.10098 c=4.45608 Z=1100.4132.616≤320 °C [35]
KCaCO3F158.18HexagonalP62ma=9.1477 c=4.4169 Z=3320.092.462≥320 °C [35]
KMnCO3F173.04HexagonalP6c2a=5.11895 c=8.42020 Z=2191.0803.008 [35]
KCuCO3F181.65 [36]
NaZnCO3F167.37hexagonalP62ca=8.4461 c=15.550 Z=12960.73.472 [37]
Na3Zn2(CO3)3F398.74monoclinicC2/ca=14.609 b=8.5274 c=20.1877 β=102.426 Z=122456.03.235213200 [38]
KZnCO3F183.48hexagonalP62ca=5.0182 c=8.355 Z=2182.213.344colourless [39]
Rb3(CO3)F335.41R3ca=7.761 c=17.412 [2]
RbCaCO3F204.56hexagonalP62ma=9.1979 c=4.4463 Z=3325.773.128 [40]
RbMgCO3F188.79HexagonalP62ma=9.0160 c=3.9403 z=3277.393.39colourless
RbZnCO3F229.85hexagonalP62ca=5.1035 c=8.619 Z=2194.43.926white [39]
KRb2(CO3)F289.04R3ca=7.6462 c=17.1364 [2]
K2Rb(CO3)F242.67R3ca=7.5225 c=16.7690 [2]
KSrCO3F205.73hexagonalP62ma=5.2598 c=4.696 Z=1112.503.037 [40]
RbSrCO3F252.10hexagonalP62ma=5.3000 c=4.7900 Z=6116.533.137 [40]
KCdCO3F230.51HexagonalPm2a=5.1324 c=4.4324 z=1101.113.786227320colourless [41]
RbCdCO3F276.88hexagonalPm21=5.2101 c=4.5293 z=1106.48350colourless [11]
Li2RbCd(CO3)2FhexagonalP63/ma=4.915 c=15.45 Z=2,323.3colourless [42]
Cs9Mg6(CO3)8F51917.13OrthorhombicPmn21a=13.289 b=6.8258 c=18.824 z=21707.43.729208 [33]
CsCaCO3F252.00hexagonalP62ma=9.92999 c=4.5400 Z=3340.053.692 [40]
CsSrCO3F230.51HexagonalPm2a=9.6286 c=4.7482 Z=3381.2<200590 [43]
KBa2(CO3)2F452.8trigonalR3a=10.119 c=18.60 Z=916484.106colourless [44]
Ba3Sc(CO3)F7649.91OrthorhombicCmcma=11.519 b=13.456 c=5.974 Z=4926.04.662colourless [45]
BaMnCO3F2290.27HexagonalP63/ma=4.9120, c=9.919 Z=2 [46] [47]
BaCoCO3F2294.27 [48]
Ba2Co(CO3)2F2491.60OrthorhombicPbcaa=6.6226, b=11.494, c=9.021 and Z=4686.7 [49]
BaNiCO3F2294.03 [48]
BaCuCO3F2298.88Cmcma=4.889 b=8.539 c=9.588 [46]
BaZnCO3F2300.72HexagonalP63/ma=4.8523, c=9.854 [47]
RbBa2(CO3)2F499.19trigonalR3a=10.2410 c=18.8277 Z=91710.14.362colourless [44]
Ba2Y(CO3)2F3540.57Pbcna=9.458 b=6.966 c=11.787 [2]
Cs3Ba4(CO3)3F51223.12hexagonalP63mca=11.516 c=7.613 Z=2874.44.646 [40]
Na3La2(CO3)4FLukechangite-(La)605.81HexagonalP63/mmca=5.083, c=23.034, Z=2 [50]
Na2Eu(CO3)F3314.94OrthorhombicPbcaa=6.596 b=10.774 c=14.09 Z=81001.34.178 [51]
Na2Gd(CO3)F3320.24orthorhombica=14.125 b=10.771 c=6.576 Z=81000.54.252<200250colourless [52]
KGd(CO3)F2294.35OrthorhombicFddda=7.006, b=11.181 and c=21.865 [53]
K4Gd2(CO3)3F4726.91R32a=9.0268 c=13.684 [2]
BaSm(CO3)2F426.70R3ma=5.016 c=37.944 [2]
Yb(CO3)(OH,F)·xH2O [54]
NaYb(CO3)F2294.04a=6.897, b=9.118, c=6.219Horvathite structure [54]
Na2Yb(CO3)2F358.04monoclinicC2/ca=17.440, b=6.100, c=11.237, β=95.64° Z=81189.7 [54]
Na3Yb(CO3)2F2400.02monoclinicCca=7.127, b=29.916, c=6.928, β=112.56°; Z=81359 [54]
Na4Yb(CO3)3F464.03monoclinicCca=8.018 b=15.929 c=13.950 β=101.425 Z=81746.43.53263300nonlinear deff=1.28pm/V [55]
Na5Yb(CO3)4·2H2O564.05 [54]
Na8Lu2(CO3)6F2899.92monoclinicCca=8.007 b=15.910 c=13.916 β=101.318 Z=417383.439250 [56]
Na3Lu(CO3)2F2401.96monoclinicCca=7.073 b=29.77 c=6.909 β=111.92 Z=813493.957220 [56]
Na2Lu(CO3)2F359.97monoclinicC2/ma=17.534 b=6.1084 c=11.284 β=111.924 Z=81203.23.974 [56]
Tl3(CO3)Fthallous fluoride carbonate692.16MonoclinicP21/ma=7.510 b=7.407 c=6.069 γ=120° Z=2hexagonal prisms [57]
Pb2(CO3)F2lead carbonate fluoride512.41OrthorhombicPbcna=8.0836 b=8.309 c=6.841 Z=4444.67.41 [2] [7]
NaPb2(CO3)2F0.9(OH)0.1HexagonalP63/mmma=5.275 c=13.479 Z=23255.893<269260band gap 4.28 eV; high birefringence [58]
KPb2(CO3)2F592.5HexagonalP63/mmca=5.3000 c=13.9302 z=2338.885.807250colourless [3]
K2.70Pb5.15(CO3)5F31529.65HexagonalP-6m2a= 5.3123 c=18.620 z=1455.075.582250colourless non-linear peizoelectric [3]
K2Pb3(CO3)3F2917.8HexagonalP63/mmca=5.2989 c=23.2326 z=2564.945.395287colourless [41]
RbPbCO3F371.67HexagonalPm2a=5.3488 c=4.8269 Z=1119.595.161colourless mon-linear [59]
CsPbCO3F419.11HexagonalPm2a=5.393 c=5.116 z=1128.85.401colourless non-linear [59]
BaPb2(CO3)2F2709.74R3ma=5.1865 c=23.4881 [2]

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Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the Chlor-alkali process.

<span class="mw-page-title-main">Bastnäsite</span> Family of minerals

The mineral bastnäsite (or bastnaesite) is one of a family of three carbonate-fluoride minerals, which includes bastnäsite-(Ce) with a formula of (Ce, La)CO3F, bastnäsite-(La) with a formula of (La, Ce)CO3F, and bastnäsite-(Y) with a formula of (Y, Ce)CO3F. Some of the bastnäsites contain OH instead of F and receive the name of hydroxylbastnasite. Most bastnäsite is bastnäsite-(Ce), and cerium is by far the most common of the rare earths in this class of minerals. Bastnäsite and the phosphate mineral monazite are the two largest sources of cerium and other rare-earth elements.

Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF2. It is a white solid that is practically insoluble in water. It occurs as the mineral fluorite (also called fluorspar), which is often deeply coloured owing to impurities.

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Praseodymium(III) chloride is the inorganic compound with the formula PrCl3. Like other lanthanide trichlorides, it exists both in the anhydrous and hydrated forms. It is a blue-green solid that rapidly absorbs water on exposure to moist air to form a light green heptahydrate.

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Ytterbium(III) oxide is the chemical compound with the formula Yb2O3. It is one of the more commonly encountered compounds of ytterbium. It occurs naturally in trace amounts in the mineral gadolinite. It was first isolated from this in 1878 by Jean Charles Galissard de Marignac.

<span class="mw-page-title-main">Strontium fluoride</span> Chemical compound

Strontium fluoride, SrF2, also called strontium difluoride and strontium(II) fluoride, is a fluoride of strontium. It is a brittle white crystalline solid. In nature, it appears as the very rare mineral strontiofluorite.

<span class="mw-page-title-main">Cobalt(II) carbonate</span> Chemical compound

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The fluoride phosphates or phosphate fluorides are inorganic double salts that contain both fluoride and phosphate anions. In mineralogy, Hey's Chemical Index of Minerals groups these as 22.1. The Nickel-Strunz grouping is 8.BN.

The carbonate chlorides are double salts containing both carbonate and chloride anions. Quite a few minerals are known. Several artificial compounds have been made. Some complexes have both carbonate and chloride ligands. They are part of the family of halocarbonates. In turn these halocarbonates are a part of mixed anion materials.

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.

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 sulfate fluorides are double salts that contain both sulfate and fluoride anions. They are in the class of mixed anion compounds. Some of these minerals are deposited in fumaroles.

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 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.

<span class="mw-page-title-main">Europium compounds</span> Compounds with at least one europium atom

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.

<span class="mw-page-title-main">Sodium tris(carbonato)cobalt(III)</span> Chemical compound

Sodium tris(carbonato)cobalt(III) is the inorganic compound with the formula Na3Co(CO3)3•3H2O. The salt contains an olive-green metastable cobalt(III) coordination complex. The salt, a homoleptic metal carbonato complex, is sometimes referred to as the “Field-Durrant precursor” and is prepared by the “Field-Durrant synthesis”. It is used in the synthesis of other cobalt(III) complexes. Otherwise cobalt(III) complexes are generated from cobalt(II) precursors, a process that requires an oxidant.

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