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.

Use in materials science[edit]

By having more than one anion, many more compounds can be made, and properties tuned to desirable values. In terms of optics, properties include laser damage threshold, refractive index, birefringence, absorption particularly in the ultraviolet or near infrared, non-linearity.[1] 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.

Production[edit]

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.[2]

Kinds[edit]

Elemental[edit]

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

Molecular anions[edit]

Oxyanions[edit]

Fluoroanions[edit]

Mixed valency and oligomers[edit]

Some elements can form several different kinds of anions, and compounds may exist with more than one. Examples include the iodate periodates,[7] sulfite sulfates and selenite selenates. These kinds also include different oligomeric forms such as phosphates or fluorotitanates, such as [Ti4F20]4- and [TiF5]−.[8]

Organic[edit]

References[edit]

  1. ^ Li, Yan-Yan; Wang, Wen-Jing; Wang, Hui; Lin, Hua; Wu, Li-Ming (7 June 2019). "Mixed-Anion Inorganic Compounds: A Favorable Candidate for Infrared Nonlinear Optical Materials". Crystal Growth & Design. 19 (7): 4172–4192. doi:10.1021/acs.cgd.9b00358.
  2. ^ Kageyama, Hiroshi; Hayashi, Katsuro; Maeda, Kazuhiko; Attfield, J. Paul; Hiroi, Zenji; Rondinelli, James M.; Poeppelmeier, Kenneth R. (22 February 2018). "Expanding frontiers in materials chemistry and physics with multiple anions". Nature Communications. 9 (1): 772. Bibcode:2018NatCo...9..772K. doi:10.1038/s41467-018-02838-4. PMC 5823932. PMID 29472526.
  3. ^ a b Xiao, Jin-Rong; Yang, Si-Han; Feng, Fang; Xue, Huai-Guo; Guo, Sheng-Ping (September 2017). "A review of the structural chemistry and physical properties of metal chalcogenide halides". Coordination Chemistry Reviews. 347: 23–47. doi:10.1016/j.ccr.2017.06.010.
  4. ^ Saparov, Bayrammurad; Singh, David J.; Garlea, Vasile O.; Sefat, Athena S. (8 July 2013). "Crystal, magnetic and electronic structures and properties of new BaMnPnF (Pn = As, Sb, Bi)". Scientific Reports. 3 (1): 2154. arXiv:1306.5182. Bibcode:2013NatSR...3E2154S. doi:10.1038/srep02154. PMC 6504822. PMID 23831607.
  5. ^ Ravnsbaek, Dorthe B.; Sørensen, Lise H.; Filinchuk, Yaroslav; Reed, Daniel; Book, David; Jakobsen, Hans J.; Besenbacher, Flemming; Skibsted, Jørgen; Jensen, Torben R. (April 2010). "Mixed-Anion and Mixed-Cation Borohydride KZn(BH4)Cl2: Synthesis, Structure and Thermal Decomposition" (PDF). European Journal of Inorganic Chemistry. 2010 (11): 1608–1612. doi:10.1002/ejic.201000119.
  6. ^ Almoussawi, Batoul; Huvé, Marielle; Dupray, Valérie; Clevers, Simon; Duffort, Victor; Mentré, Olivier; Roussel, Pascal; Arevalo-Lopez, Angel M.; Kabbour, Houria (22 April 2020). "Oxysulfide Ba5(VO2S2)2(S2)2 Combining Disulfide Channels and Mixed-Anion Tetrahedra and Its Third-Harmonic-Generation Properties" (PDF). Inorganic Chemistry. 59 (9): 5907–5917. doi:10.1021/acs.inorgchem.9b03674. PMID 32319754.
  7. ^ Sun, Jun; Abudouwufu, Tushagu; Jin, Congcong; Guo, Zhiyong; Zhang, Min (17 December 2021). "K 6 (IO 6 H 4 )(HI 2 O 6 )(HIO 3 ) 2 (IO 3 ) 4 ·2H 2 O: A Case of Iodate with Coexisting [I 5+ O 3 ] and [I 7+ O 6 ] Units". Inorganic Chemistry. 61 (1): 688–692. doi:10.1021/acs.inorgchem.1c03436. PMID 34919392.
  8. ^ Shlyapnikov, Igor M.; Goreshnik, Evgeny A.; Mazej, Zoran (31 December 2018). "Guanidinium Perfluoridotitanate(IV) Compounds: Structural Determination of an Oligomeric [Ti6F27]3– Anion, and an Example of a Mixed-Anion Salt Containing Two Different Fluoridotitanate(IV) Anions". European Journal of Inorganic Chemistry. 2018 (48): 5246–5257. doi:10.1002/ejic.201801207. S2CID 104344701.