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Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. The corresponding electrically neutral compound HO• is the hydroxyl radical. The corresponding covalently bound group –OH of atoms is the hydroxy group. Both the hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry.
High-temperature superconductors are defined as materials with critical temperature above 77 K, the boiling point of liquid nitrogen. They are only "high-temperature" relative to previously known superconductors, which function at even colder temperatures, close to absolute zero. The "high temperatures" are still far below ambient, and therefore require cooling. The first break through of high-temperature superconductor was discovered in 1986 by IBM researchers Georg Bednorz and K. Alex Müller. Although the critical temperature is around 35.1 K, this new type of superconductor was readily modified by Ching-Wu Chu to make the first high-temperature superconductor with critical temperature 93 K. Bednorz and Müller were awarded the Nobel Prize in Physics in 1987 "for their important break-through in the discovery of superconductivity in ceramic materials". Most high-Tc materials are type-II superconductors.
Yttrium barium copper oxide (YBCO) is a family of crystalline chemical compounds that display high-temperature superconductivity; it includes the first material ever discovered to become superconducting above the boiling point of liquid nitrogen [77 K ] at about 93 K.
In the area of solid state chemistry. graphite intercalation compounds are materials prepared by intercalation of diverse guests into graphite. The materials have the formula (guest)Cn where n can range from 8 to 40's. The distance between the carbon layers increases significantly upon insertion of the guests. Common guests are reducing agents such as alkali metals. Strong oxidants, such as arsenic pentafluoride also intercalate into graphite. Intercalation involves electron transfer into or out of the host. The properties of these materials differ from those of the parent graphite.
Lithium iron phosphate or lithium ferro-phosphate (LFP) is an inorganic compound with the formula LiFePO
4. It is a gray, red-grey, brown or black solid that is insoluble in water. The material has attracted attention as a component of lithium iron phosphate batteries, a type of Li-ion battery. This battery chemistry is targeted for use in power tools, electric vehicles, solar energy installations and more recently large grid-scale energy storage.
Cuprate superconductors are a family of high-temperature superconducting materials made of layers of copper oxides (CuO2) alternating with layers of other metal oxides, which act as charge reservoirs. At ambient pressure, cuprate superconductors are the highest temperature superconductors known. However, the mechanism by which superconductivity occurs is still not understood.
Iron-based superconductors (FeSC) are iron-containing chemical compounds whose superconducting properties were discovered in 2006. In 2008, led by recently discovered iron pnictide compounds, they were in the first stages of experimentation and implementation..
Thallium barium calcium copper oxide, or TBCCO (pronounced "tibco"), is a family of high-temperature superconductors having the generalized chemical formula TlmBa2Can−1CunO2n+m+2.
In chemistry, oxypnictides are a class of materials composed of oxygen, a pnictogen and one or more other elements. Although this group of compounds has been recognized since 1995, interest in these compounds increased dramatically after the publication of the superconducting properties of LaOFeP and LaOFeAs which were discovered in 2006 and 2008. In these experiments the oxide was partly replaced by fluoride.
The 122 iron arsenide unconventional superconductors are part of a new class of iron-based superconductors. They form in the tetragonal I4/mmm, ThCr2Si2 type, crystal structure. The shorthand name "122" comes from their stoichiometry; the 122s have the chemical formula AEFe2Pn2, where AE stands for alkaline earth metal (Ca, Ba Sr or Eu) and Pn is pnictide (As, P, etc.). These materials become superconducting under pressure and also upon doping. The maximum superconducting transition temperature found to date is 38 K in the Ba0.6K0.4Fe2As2. The microscopic description of superconductivity in the 122s is yet unclear.
Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion (CH
3COCHCOCH−
3) and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2. Mixed-ligand complexes, e.g. VO(acac)2, are also numerous. Variations of acetylacetonate have also been developed with myriad substituents in place of methyl (RCOCHCOR′−). Many such complexes are soluble in organic solvents, in contrast to the related metal halides. Because of these properties, acac complexes are sometimes used as catalyst precursors and reagents. Applications include their use as NMR "shift reagents" and as catalysts for organic synthesis, and precursors to industrial hydroformylation catalysts. C
5H
7O−
2 in some cases also binds to metals through the central carbon atom; this bonding mode is more common for the third-row transition metals such as platinum(II) and iridium(III).
Hideo Hosono is a Japanese material scientist most known for the discovery of iron-based superconductors.
Nickel compounds are chemical compounds containing the element nickel which is a member of the group 10 of the periodic table. Most compounds in the group have an oxidation state of +2. Nickel is classified as a transition metal with nickel(II) having much chemical behaviour in common with iron(II) and cobalt(II). Many salts of nickel(II) are isomorphous with salts of magnesium due to the ionic radii of the cations being almost the same. Nickel forms many coordination complexes. Nickel tetracarbonyl was the first pure metal carbonyl produced, and is unusual in its volatility. Metalloproteins containing nickel are found in biological systems.
Malhmoodite is a phosphate mineral first discovered at a mine called Union Carbide in Wilson Springs, Arkansas, United States. This mine is 10 km west of Magnet Cove, an alkaline igneous complex, and Union Carbide is in a contact region of alkalic igneous rocks and surrounding sedimentary rocks. The mineral has been approved by the Commission on New Minerals and Mineral Names, IMA, to be named for the late Bertha K. Malhmood, the Administrative Assistant of the Branch of Analytical Laboratories, U.S. Geological Survey.
Oxyarsenides or arsenide oxides are chemical compounds formally containing the group AsO, with one arsenic and one oxygen atom. The arsenic and oxygen are not bound together as in arsenates or arsenites, instead they make a separate presence bound to the cations (metals), and could be considered as a mixed arsenide-oxide compound. So a compound with OmAsn requires cations to balance a negative charge of 2m+3n. The cations will have charges of +2 or +3. The trications are often rare earth elements or actinides. They are in the category of oxypnictide compounds.
Phosphide silicides or silicide phosphides or silicophosphides are compounds containing anions composed of silicide (Si4−) and phosphide (P3−). They can be considered as mixed anion compounds. They are distinct from the phosphidosilicates, which have the phosphorus bonded to the silicon. Related compounds include the phosphide carbides, germanide phosphides, nitride silicides, and antimonide silicides.
A transition metal nitrate complex is a coordination compound containing one or more nitrate ligands. Such complexes are common starting reagents for the preparation of other compounds.
Phosphide iodides or iodide phosphides are compounds containing anions composed of iodide (I−) and phosphide (P3−). They can be considered as mixed anion compounds. They are in the category of pnictidehalides. Related compounds include the phosphide chlorides, arsenide iodides antimonide iodides and phosphide bromides.
Erbium compounds are compounds containing the element erbium (Er). These compounds are usually dominated by erbium in the +3 oxidation state, although the +2, +1 and 0 oxidation states have also been reported.
References
- 1 2 3 Sakai, Hironori; Tateiwa, Naoyuki; D. Matsuda, Tatsuma; Sugai, Takashi; Yamamoto, Etsuji; Haga, Yoshinori (15 July 2010). "Crystal Structure and Physical Properties of Uranium–Copper Oxyphosphide UCuPO". Journal of the Physical Society of Japan. 79 (7): 074721. Bibcode:2010JPSJ...79g4721H. doi:10.1143/JPSJ.79.074721.
- ↑ Hadenfeldt, C; Vollert, H.O (December 1988). "Darstellung und kristallstruktur der calciumpnictidoxide Ca4P2O und Ca4As2O". Journal of the Less Common Metals. 144 (2): 143–151. doi:10.1016/0022-5088(88)90126-9.
- ↑ Wells, Daniel M.; Ringe, Emilie; Kaczorowski, D.; Gnida, D.; André, G.; Haire, Richard G.; Ellis, Donald E.; Ibers, James A. (17 January 2011). "Structure, Properties, and Theoretical Electronic Structure of UCuOP and NpCuOP". Inorganic Chemistry. 50 (2): 576–589. doi:10.1021/ic101665g. PMID 21158457.
- 1 2 has layers of CoP alternating with Sr2ScO3.Okada, S; Kamihara, Y; Ohkubo, N; Ban, S; Matoba, M; Atou, T (17 December 2012). "Physical properties of the novel layered cobalt oxyphosphide Sr2ScCoPO3". Journal of Physics: Conference Series. 400 (2): 022091. Bibcode:2012JPhCS.400b2091O. doi: 10.1088/1742-6596/400/2/022091 .
- ↑ Ogino, Hiraku; Matsumura, Yutaka; Katsura, Yukari; Ushiyama, Koichi; Horii, Shigeru; Kishio, Kohji; Shimoyama, Jun-ichi (1 July 2009). "Superconductivity at 17 K in (Fe2P2)(Sr4Sc2O6): a new superconducting layered pnictide oxide with a thick perovskite oxide layer". Superconductor Science and Technology. 22 (7): 075008. arXiv: 0903.3314 . Bibcode:2009SuScT..22g5008O. doi:10.1088/0953-2048/22/7/075008. S2CID 118525802.
- ↑ Watanabe, Takumi; Yanagi, Hiroshi; Kamiya, Toshio; Kamihara, Yoichi; Hiramatsu, Hidenori; Hirano, Masahiro; Hosono, Hideo (September 2007). "Nickel-Based Oxyphosphide Superconductor with a Layered Crystal Structure, LaNiOP". Inorganic Chemistry. 46 (19): 7719–7721. doi:10.1021/ic701200e. PMID 17705374.
- 1 2 3 Moreau, Meghann A. "Flux Synthesis and Characterization of Layered Oxyphosphides in the YOMP System (M=Fe, Mn, Cd)". The 7th Annual NC State University Undergraduate Summer Research Symposium. Retrieved 16 January 2017.
- ↑ Lorenz, B.; Sasmal, K.; Chaudhury, R. P.; Chen, X. H.; Liu, R. H.; Wu, T.; Chu, C. W. (2008). "Pressure Effects on the Superconducting and Spin-Density-Wave States of the Newly Discovered Sm(O1-XFX)FeAs". arXiv: 0804.1582v1 [cond-mat.supr-con].
- 1 2 3 4 5 6 7 8 9 10 11 Lincke, Hannes; Glaum, Robert; Dittrich, Volker; Tegel, Marcus; Johrendt, Dirk; Hermes, Wilfried; Möller, Manfred H.; Nilges, Tom; Pöttgen, Rainer (July 2008). "Magnetic, Optical, and Electronic Properties of the Phosphide OxidesREZnPO (RE = Y, La–Nd, Sm, Gd, Dy, Ho)". Zeitschrift für anorganische und allgemeine Chemie. 634 (8): 1339–1348. doi:10.1002/zaac.200800066.
- 1 2 3 4 Bartsch, Timo; Wiegand, Thomas; Ren, Jinjun; Eckert, Hellmut; Johrendt, Dirk; Niehaus, Oliver; Eul, Matthias; Pöttgen, Rainer (18 February 2013). "Phosphide Oxides M2AuP2O (M= La, Ce, Pr, Nd): Synthesis, Structure, Chemical Bonding, Magnetism, and 31P and 131La Solid State NMR". Inorganic Chemistry. 52 (4): 2094–2102. doi:10.1021/ic302475u. PMID 23374070.
- ↑ Kozhevnikov, V. L.; Leonidova, O. N.; Ivanovskii, A. L.; Shein, I. R.; Goshchitskii, B. N.; Kar’kin, A. E. (5 February 2009). "New superconductor with a layered crystal structure: Nickel oxybismuthide LaO1−δNiBi". JETP Letters. 87 (11): 649–651. Bibcode:2008JETPL..87..649K. doi:10.1134/S002136400811012X. S2CID 120451483.