Aluminium fluoride

From Wikipedia, the free encyclopedia
(Redirected from Aluminum fluoride)
Jump to navigation Jump to search

<templatestyles src="Chembox/styles.css"/>

Template:Chembox image cellTemplate:Chembox AllOtherNamesTemplate:Chembox headerbarTemplate:Chembox IndexlistTemplate:Chembox JmolTemplate:Chembox ChEMBLTemplate:Chembox ECHATemplate:Chembox E numberTemplate:Chembox IUPHAR ligandTemplate:Chembox UNIITemplate:Chembox CompToxTemplate:Chembox headerbarTemplate:Chembox SolubilityInWaterTemplate:Chembox headerbarTemplate:Chembox CrystalStructVolumeTemplate:Chembox CrystalStructFormulasTemplate:Chembox headerbarTemplate:Chembox DeltaGfreeTemplate:Chembox headerbarTemplate:Chembox GHS (set)Template:Chembox setHeaderTemplate:Chembox setDatarowTemplate:Chembox setDatarowTemplate:Chembox setDatarowTemplate:Chembox SDSTemplate:Chembox headerbarTemplate:Chembox Datapage checkTemplate:Chembox Footer
Aluminium fluoride
Template:Longitem Template:Unbulleted list
ChEBI Template:Unbulleted list
ChemSpider Template:Unbulleted list
DrugBank Template:Unbulleted list
EC Number Template:Unbulleted list
KEGG Template:Unbulleted list
Template:Longitem Template:Unbulleted list
RTECS number Template:Unbulleted list
Script error: No such module "collapsible list".
Script error: No such module "collapsible list".
Template:Longitem Template:Chem2
Molar mass Template:Ubl[1]
Appearance Colorless to white crystalline solid
Odor Odorless
Density Template:Ubl[1]
Melting point Template:Chembox CalcTemperatures
Template:Longitem Script error: No such module "val".[2]
Template:Longitem 1.3767 (visible range)[3]
Template:Longitem Rhombohedral, hR24
Template:Longitem R3c, No. 167[4]
Template:Longitem
a = 0.49254 nm, c = 1.24477 nm
Template:Longitem 75.1 J/(mol·K)[5]
Template:Longitem 66.5 J/(mol·K)[5]
Template:Longitem −1510.4 kJ/mol[5]
NFPA 704 (fire diamond) Template:NFPA 704 diamond
Template:Longitem Template:Ubl
Template:Longitem Template:Ubl
Template:Longitem Template:Ubl

Template:Chembox Footer/trackingScript error: No such module "TemplatePar".Template:Short description

Aluminium fluoride is an inorganic compound with the formula Template:Chem2. It forms hydrates Template:Chem2. Anhydrous Template:Chem2 and its hydrates are all colorless solids. Anhydrous Template:Chem2 is used in the production of aluminium. Several occur as minerals.

Occurrence and production

Aside from anhydrous Template:Chem2, several hydrates are known. With the formula Template:Chem2, these compounds include monohydrate (x = 1), two polymorphs of the trihydrate (x = 3), a hexahydrate (x = 6), and a nonahydrate (x = 9).[6]

The majority of aluminium fluoride is produced by treating alumina with hydrogen fluoride at 700 °C:[7] Hexafluorosilicic acid may also be used make aluminium fluoride.[8]

Template:Chem2

Alternatively, it is manufactured by thermal decomposition of ammonium hexafluoroaluminate.[9] For small scale laboratory preparations, Template:Chem2 can also be prepared by treating aluminium hydroxide or aluminium with hydrogen fluoride.

Aluminium fluoride trihydrate is found in nature as the rare mineral rosenbergite.

The anhydrous form appears as the relatively recently (as of 2020) recognized mineral óskarssonite.[10][11] A related, exceedingly rare mineral, is zharchikhite, Template:Chem2.[12][11]

Structure

According to X-ray crystallography, anhydrous Template:Chem2 adopts the rhenium trioxide motif, featuring distorted Template:Chem2 octahedra. Each fluoride is connected to two Al centers. Because of its three-dimensional polymeric structure, Template:Chem2 has a high melting point. The other trihalides of aluminium in the solid state differ, [[Aluminium chloride|Template:Chem2]] has a layer structure and [[aluminium bromide|Template:Chem2]] and [[aluminium iodide|Template:Chem2]], are molecular dimers.[13]Script error: No such module "Unsubst". Also they have low melting points and evaporate readily to give dimers.[14]Script error: No such module "Unsubst". In the gas phase aluminium fluoride exists as trigonal molecules of D3h symmetry. The Al–F bond lengths of this gaseous molecule are 163 pm.

File:Aluminium-trifluoride-monomer-2D-dimensions.png
Like most gaseous metal trifluorides, Template:Chem2 adopts a planar structure upon evaporation.

Applications

Aluminium fluoride is an important additive for the production of aluminium by electrolysis.[7] Together with cryolite, it lowers the melting point to below 1000 °C and increases the conductivity of the solution. It is into this molten salt that aluminium oxide is dissolved and then electrolyzed to give bulk Al metal.[9]

Aluminium fluoride complexes are used to study the mechanistic aspects of phosphoryl transfer reactions in biology, which are of fundamental importance to cells, as phosphoric acid anhydrides such as adenosine triphosphate and guanosine triphosphate control most of the reactions involved in metabolism, growth and differentiation.[15] The observation that aluminium fluoride can bind to and activate heterotrimeric G proteins has proven to be useful for the study of G protein activation in vivo, for the elucidation of three-dimensional structures of several GTPases, and for understanding the biochemical mechanism of GTP hydrolysis, including the role of GTPase-activating proteins.[16]

Niche uses

Together with zirconium fluoride, aluminium fluoride is an ingredient for the production of fluoroaluminate glasses.

It is also used to inhibit fermentation.

Like magnesium fluoride it is used as a low-index optical thin film, particularly when far UV transparency is required. Its deposition by physical vapor deposition, particularly by evaporation, is favorable.

Safety

The reported oral animal lethal dose (LD50) of aluminium fluoride is 100 mg/kg.[17] Repeated or prolonged inhalation exposure may cause asthma, and may have effects on the bone and nervous system, resulting in bone alterations (fluorosis), and nervous system impairment.[18]

Many of the neurotoxic effects of fluoride are due to the formation of aluminium fluoride complexes, which mimic the chemical structure of a phosphate and influence the activity of ATP phosphohydrolases and phospholipase D. Only micromolar concentrations of aluminium are needed to form aluminium fluoride.[19]

Human exposure to aluminium fluoride can occur in an industrial setting, such as emissions from aluminium reduction processes,[20] or when a person ingests both a fluoride source (e.g., fluoride in drinking water or residue of fluoride-based pesticides) and an aluminium source; sources of human exposure to aluminium include drinking water, tea, food residues, infant formula, aluminium-containing antacids or medications, deodorants, cosmetics, and glassware.[19] Fluoridation chemicals may also contain aluminium fluoride.[21] Data on the potential neurotoxic effects of chronic exposure to the aluminium species existing in water are limited.[22]

See also

References

<templatestyles src="Reflist/styles.css" />

  1. ↑ a b Template:RubberBible92nd
  2. ↑ Template:RubberBible92nd
  3. ↑ Script error: No such module "citation/CS1".
  4. ↑ Script error: No such module "Citation/CS1".
  5. ↑ a b c d Template:RubberBible92nd
  6. ↑ Script error: No such module "Citation/CS1".
  7. ↑ a b Script error: No such module "citation/CS1".
  8. ↑ Script error: No such module "Citation/CS1".
  9. ↑ a b Script error: No such module "Template wrapper".
  10. ↑ Script error: No such module "citation/CS1".
  11. ↑ a b Script error: No such module "citation/CS1".
  12. ↑ Script error: No such module "citation/CS1".
  13. ↑ Script error: No such module "citation/CS1".
  14. ↑ Script error: No such module "citation/CS1"..
  15. ↑ Script error: No such module "Citation/CS1".
  16. ↑ Script error: No such module "Citation/CS1".
  17. ↑ Script error: No such module "citation/CS1".
  18. ↑ Script error: No such module "citation/CS1".
  19. ↑ a b Script error: No such module "citation/CS1".
  20. ↑ Script error: No such module "citation/CS1".
  21. ↑ Script error: No such module "Citation/CS1".
  22. ↑ Aluminum Compounds Review of Toxicological Literature Abridged Final Report. Prepared for National Institute of Environmental Health Sciences. NTP.gov Nomination Summary for Aluminum contaminants of drinking water (N20025). October 2001

Script error: No such module "Check for unknown parameters".

External links

Script error: No such module "Side box".

Script error: No such module "Navbox". Template:Fluorine compounds Script error: No such module "Authority control".

Retrieved from "http://debianws.lexgopc.com/wiki143/index.php?title=Aluminium_fluoride&oldid=2821489"