Arsenate arsenite explained

An arsenate arsenite is a chemical compound or salt that contains arsenate and arsenite anions (AsO₃^3- and AsO₄^3-). These are mixed anion compounds or mixed valence compounds. Some have third anions. Most known substances are minerals, but a few artificial arsenate arsenite compounds have been made. Many of the minerals are in the Hematolite Group.

An arsenate arsenite compound may also be called an arsenite arsenate.

Properties

Some members of this group of materials like mcgovernite has an extremely high unit cell dimension of 204 Å.^[1]

Related

Mixed valence pnictide compounds related to the arsenate arsenites include the nitrite nitrates, and phosphate phosphites.

List

name	formula	ratioAsO4:AsO3	system	space group	unit cell Å	volume	density	properties	references
Arsenic dioxide	AsO2	1:1	orthorhomnic	Pnma	a=8.597 b=5.235 c=7.269 Z=8	327.1	4.382		^[2]
Arsenic(III) Arsenic(V) Oxide Hydroxide	As3O5(OH)	1:2	monoclinic	P21/c	a = 12.504 b = 4.593 c = 10.976 β = 118.08° Z = 4	556.2	3.84		^[3]
	H6As^3+7As^5+7O31	1:1	hexagonal	P63	a = 12.0525 c = 4.7344 Z = 2	595.6			^[4]
Segerstromite	Ca3(As^5+O4)2[As<sup>3+</sup>(OH)<sub>3</sub>]2	2:1	cubic	I213	a = 10.7627 Z = 4	1246.71	3.46	colourless; refract index: n = 1.731	^[5]
Synadelphite	Mn^2+9(As^5+O4)2(As^3+O3)(OH)9 · 2H2O	2:1	Orthorhombic	Pnma	a = 10.75 b = 18.86c = 9.88 Z=4	2005	3.58	red; Biaxial (+); refract index: nα = 1.750 - 1.870 nβ = 1.751 - 1.880 nγ = 1.761 - 1.930	^[6]
Hematolite	(Mn,Mg,Al,Fe^3+)15(As^5+O4)2(As^3+O3)(OH)23	2:1	trigonal	R	a = 8.275 Å, c = 36.60 Å Z=3	2,170.4	3.49	deep red; Uniaxial (-) refractive index nω = 1.733 nε = 1.714; Birefringence: 0.019	^[7] ^[8]
Turtmannite	(Mn,Mg)22.5Mg3-3x((V^5+,As^5+)O4)3(As^3+O3)x(SiO4)3O5-5x(OH)20+x		trigonal		a = 8.259 c = 204.3 Z=12	12,068	3.8	light yellow; Uniaxial (-); refractive index: nε = 1.787	^[9]
Carlfrancisite	Mn^2+3(Mn^2+,Mg,Fe^3+,Al)42[As<sup>3+</sup>O<sub>3</sub>]2(As^5+O4)4[(Si,As<sup>5+</sup>)O<sub>4</sub>]6[(As<sup>5+</sup>,Si)O<sub>4</sub>]2(OH)42		trigonal	Rc	a = 8.2238 c = 205.113 Z=6	12,013.5	3.620	yellow-orange; Uniaxial (+) refractive index: nω = 1.756(2) nε = 1.758 Birefringence: δ = 0.002	^[10]
	K2Cu3(As2O6)2	1:1	monoclinic	C2m	a=10.359 b=5.388 c=11.234 β=110.48°			[As(V)As(III)O<sub>6</sub>]^4−	^[11]
Dixenite	CuMn^2+14Fe^2+(SiO4)2(As^5+O4)(As^3+O3)5(OH)6	1:5	trigonal	R3	a = 8.233 c = 37.499 Z=3	2201	4.35	deep red-brown; Uniaxial (+) refractive index nω = 1.970 nε = 1.730	^[12]
Arakiite	(Zn,Mn^2+)(Mn^2+,Mg)12(Fe^3+,Al)2(As^5+O4)2(As^3+O3)(OH)23	2:1	monoclinic	Cc	a = 14.248 b = 8.228 c = 24.23 β = 93.62° Z=4	2843	3.41	orange-red brown; Biaxial (-); refract index: nα = 1.723 nβ = 1.744 nγ = 1.750Birefringence: 0.027	^[13]
Kraisslite	Zn3(Mn,Mg)25(Fe^3+,Al)(As^3+O3)2[(Si,As<sup>5+</sup>)O<sub>4</sub>]10(OH)16	5:1	Orthorhombic	C2221	a = 8.1821 b = 14.1946 c = 43.9103 Z=4	5099.8	3.876	pale red; Uniaxial (+) Refractive index: nε = 1.805	^[14]
Mcgovernite	Mn19Zn3(AsO4)3(AsO3)(SiO4)3(OH)21	3:1	trigonal	R3m or Rm	a = 8.22 c = 203.1 Z=6	11,887.52	3.719	brown; Uniaxial (+) Refractive index: nω = 1.757 nε = 1.760Birefringence: δ = 0.003	^[15]
Halilsarpite	[Mg(H<sub>2</sub>O)<sub>6</sub>][CaAs<sup>3+</sup><sub>2</sub>(Fe<sup>3+</sup><sub>2.67</sub>Mo<sup>6+</sup><sub>0.33</sub>)(AsO<sub>4</sub>)<sub>2</sub>O<sub>7</sub>]		orthorhomnic	Imma	a = 26.489 b = 7.4205 c = 10.4378	2051.7		lemon yellow; Biaxial (-) refractive index: nα = 1.646 nβ = 1.765(5) nγ = 1.815(5) 2V: 62° Max Birefringence: δ = 0.169	^[16]
Wiklundite	Pb2(Mn^2+,Zn)3(Fe^3+,Mn^2+)2(Mn^2+,Mg)19(As^3+O3)2[(Si,As<sup>5+</sup>)O<sub>4</sub>]6(OH)18Cl6		hexagonal	? Rc	a = 8.257 c = 126.59 Z = 6	7474	4.072	dark reddish brown	^[17]
	Bi8O6(AsO3)2(AsO4)2		monoclinic	I2/a	a=24.372 b=5.528 c=29.90 β=99.058 Z=8	3978	7.652	colourless	^[18]
	Th(As^III4As^V4O18)	1:1	monoclinic	C2/c	a=18.2148 b 5.19792 c=17.3588 β=99.1298 Z=4	1622.70	4.582	colourless	^[19]

Notes and References

1. Moore . P. B. . Araki . T . Hematolite; a complex dense-packed sheet structure . American Mineralogist . 1 February 1978 . 63 . 1–2 . 150–159 .
2. Jones . P. G. . Beesk . W. . Sheldrick . G. M. . Sharman . E. . 1980-02-01 . Arsenic dioxide . Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry . 36 . 2 . 439–440 . 10.1107/S0567740880003433 . 0567-7408. subscription .
3. Bodenstein . Doris . Brehm . Axel . Jones . Peter G. . Schwarzmann . Einhard . Sheldrick . George M. . 1982-02-01 . Darstellung und Kristallstruktur vom Arsen(III)arsen(V)oxidhydroxid As 3 O 5 (0H) / Preparation and Crystal Structure of the Arsenic(III) Arsenic(V) Oxide Hydroxide As 3 O 5 (OH) . Zeitschrift für Naturforschung B . en . 37 . 2 . 138–140 . 10.1515/znb-1982-0204 . 96596612 . 1865-7117. free .
4. Orosel . Denis . Dinnebier . Robert E. . Balog . Paul . Jansen . Martin . July 2007 . The crystal structure of a new mixed valence arsenic(III,V)oxoacid H 6 As 3+ 7 As 5+ 7 O 31 . Zeitschrift für Kristallographie . en . 222 . 7 . 321–325 . 10.1524/zkri.2007.222.7.321 . 2007ZK....222..321O . 95624012 . 0044-2968. subscription .
5. Yang . Hexiong . Downs . Robert T. . Jenkins . Robert A. . Evans . Stanley H. . 2018-09-01 . Segerstromite, Ca3(As5+O4)2[As3+(OH)3]2, the first mineral containing As3+(OH)3, the arsenite molecule, from the Cobriza mine in the Atacama Region, Chile ]. American Mineralogist . en . 103 . 9 . 1497–1501 . 10.2138/am-2018-6329 . 2018AmMin.103.1497Y . 106199868 . 0003-004X. subscription .
6. Web site: Synadelphite . Mindat.
7. Web site: Hematolite . Mindat.
8. Dunn . Pete J. . Peacor . Donald R. . September 1983 . A ferric iron equivalent of hematolite from Sterling Hill, New Jersey and Långban, Sweden . Mineralogical Magazine . en . 47 . 344 . 381–385 . 10.1180/minmag.1983.047.344.15 . 1983MinM...47..381D . 129662981 . 0026-461X.
9. Web site: Turtmannite . Mindat.
10. Web site: Carlfrancisite . Mindat.
11. Effenberger . H. . Pertlik . F. . October 1987 . [As(V)As(III)O6]4−: An uncommon anion group in the crystal structure of K2Cu3(As2O6)2 ]. Journal of Solid State Chemistry . en . 70 . 2 . 219–224 . 10.1016/0022-4596(87)90059-4. 1987JSSCh..70..219E .
12. Web site: Dixenite . Mindat.
13. Web site: Arakiite . Mindat.
14. Web site: Kraisslite . Mindat.
15. Web site: Mcgovernite . Mindat.
16. Husdal . Tomas . Grey . Ian E. . Friis . Henrik . Dal Bo . Fabrice . Kampf . Anthony R. . MacRae . Colin M. . Mumme . W. Gus . Ljøstad . Ole-Thorstein . Shanks . Finlay . 2020-01-23 . Halilsarpite, a new arsenate analogue of walentaite, from the Oumlil mine, Bou Azzer district, Morocco . European Journal of Mineralogy . en . 32 . 1 . 89–98 . 10.5194/ejm-32-89-2020 . 2020EJMin..32...89H . 211082062 . 1617-4011. 10852/76149 . free . free .
17. Cooper . Mark A. . Hawthorne . Frank C. . Langhof . Jörgen . Hålenius . Ulf . Holtstam . Dan . August 2017 . Wiklundite, ideally Pb 2 [4] (Mn 2+,Zn) 3 (Fe 3+,Mn 2+) 2 (Mn 2+,Mg) 19 (As 3+ O 3) 2 [(Si,As 5+)O 4 ] 6 (OH) 18 Cl 6, a new mineral from Långban, Filipstad, Värmland, Sweden: Description and crystal structure ]. Mineralogical Magazine . en . 81 . 4 . 841–855 . 10.1180/minmag.2016.080.136 . 2017MinM...81..841C . 103754064 . 0026-461X. subscription .
18. Liu . Jun-Hui . Kong . Fang . Gai . Yan-Li . Mao . Jiang-Gao . January 2013 . Syntheses, crystal structures and characterizations of two new bismuth(III) arsenites . Journal of Solid State Chemistry . en . 197 . 228–235 . 10.1016/j.jssc.2012.08.019. subscription .
19. Yu. Na. Klepov. Vladislav V.. Kegler. Philip. Bosbach. Dirk. Albrecht-Schmitt. Thomas E.. Alekseev. Evgeny V.. 2014-08-18. Th(As III 4 As V 4 O 18): a Mixed-Valent Oxoarsenic(III)/arsenic(V) Actinide Compound Obtained under Extreme Conditions. Inorganic Chemistry. en. 53. 16. 8194–8196. 10.1021/ic5013704. 25075555 . 0020-1669.