Mixed-anion compounds
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
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
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 reulst in different crystal forms, perhaps with higher coordination number.[2]
Kinds
Elemental
- pnictochalcogenides
- oxypnictides, including oxynitrides, oxyphosphides, oxyarsenides, oxyantimonides, and oxybismuthides
- chalcohalides or chalcogenide halides[3]
- oxysulfides and oxyselenides
- oxyhydrides
- halopnictides
- fluoropnictides, including fluorophosphides, fluoroarsenides, fluoroantimonides, and fluorobismuthides[4]
Molecular anions
- borohydride-chloride[5]
- disulfide dithioorthovanadate[6]
Oxyanions
- halocarbonates, including carbonate fluorides, carbonate chlorides, and carbonate bromides
- phosphates, including fluoride phosphates, chloride phosphate, phosphate molybdates, and phosphate arsenates
- borates
- halide borates, including fluoride borates
- chalcogenide borates, including sulfide borates[3]
- sulfates
- selenite fluorides
- iodate fluorides,
- Silicates
Fluoroanions
Oligomers
Some pairs of elements can form several different anions, and compounds may exist with more than one. One example is the sulfite sulfates. These kinds also include different oligomeric forms such as phosphates or fluorotitanates, such as [Ti4F20]4- and [TiF5]-.[7]
Organic
References
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.