Antimony pentafluoride is the chemical compound A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds with the formula Sb Antimony [note 1] is a chemical element with the symbol Sb (Latin: stibium, meaning "mark") and atomic number 51. A metalloid, antimony has four allotropic forms. The stable form of antimony is a blue-white metalloid. Yellow and black antimony are unstable non-metals. Antimony is used in electronics and flame-proofing, in paints, rubber, F Fluorine is the chemical element with atomic number 9, represented by the symbol F. Fluorine forms a single bond with itself in elemental form, resulting in the diatomic F2 molecule. F2 is a supremely reactive, poisonous, pale, yellowish brown gas. Elemental fluorine is the most chemically reactive and electronegative of all the elements. For5. This colourless, viscous liquid is a valuable Lewis acid Gilbert N. Lewis proposed this definition, which is based on chemical bonding theory, in 1923. Brønsted-Lowry acid-base theory was published in the same year. The two theories are distinct but complementary to each other as a Lewis base is also a Brønsted-Lowry base, but a Lewis acid need not be a Brønsted-Lowry acid and a component of the superacid A superacid is an acid with an acidity greater than that of 100% pure sulfuric acid, which has a Hammett acidity function of −12. Commercially available superacids include trifluoromethanesulfonic acid (CF3SO3H), also known as triflic acid, and fluorosulfonic acid (FSO3H), both of which are about a thousand times stronger (i.e. have more fluoroantimonic acid Fluoroantimonic acid HSbF6 is a mixture of hydrogen fluoride and antimony pentafluoride in various ratios. The 1:1 combination affords the strongest known superacid, which has been demonstrated to protonate even hydrocarbons to afford carbocations and H2, the strongest known acid. Some features that give the compound scientific interest are its Lewis acidity Gilbert N. Lewis proposed this definition, which is based on chemical bonding theory, in 1923. Brønsted-Lowry acid-base theory was published in the same year. The two theories are distinct but complementary to each other as a Lewis base is also a Brønsted-Lowry base, but a Lewis acid need not be a Brønsted-Lowry acid and that it also reacts with almost all known compounds.[2]

Contents

Preparation

Antimony pentafluoride is prepared by the reaction of antimony pentachloride with anhydrous hydrogen fluoride Hydrogen fluoride is a chemical compound with the formula HF. It is the principal industrial source of fluorine, often in the aqueous form as hydrofluoric acid, and thus is the precursor to many important compounds including pharmaceuticals and polymers . HF is widely used in the petrochemical industry and a component of many superacids. HF boils:

SbCl5 + 5 HF → SbF5 + 5 HCl

It may also be prepared from antimony trifluoride and fluorine, or by treating antimony pentoxide with aqueous hydrofluoric acid Hydrofluoric acid is a solution of hydrogen fluoride in water. While it is extremely corrosive and difficult to handle, it is technically a weak acid. Hydrogen fluoride, often in the aqueous form as hydrofluoric acid, is a valued source of fluorine, being the precursor to numerous pharmaceuticals such as fluoxetine (Prozac), diverse polymers such and evaporing water.

Structure and chemical reactions

In the gas phase, SbF5 adopts a trigonal bipyramidal structure of D3h point group symmetry The symmetry group of an object is the group of all isometries under which it is invariant with composition as the operation. It is a subgroup of the isometry group of the space concerned (see picture). The structure is more complex in the liquid and solid state. The liquid contains polymers wherein each Sb is octahedral, the structure being described with the formula [SbF4(μ-F)2]n. The crystalline material is tetrameric, i.e. it has the formula [SbF4(μ-F)]4. The Sb-F bonds are 2.02 Å within the eight-membered Sb4F4 ring; the remaining fluoride ligands radiating from the four Sb centers are shorter at 1.82 Å.[3] The related species PF5 and AsF5 are monomeric A monomer is a small molecule that may become chemically bonded to other monomers to form a polymer. The most common natural monomer is glucose, which is linked by glycosidic bonds into polymers such as cellulose and starch, and is over 76% of the weight of all plant matter in the solid and liquid states, probably due to the smaller sizes of the central atom, which limits their coordination number. BiF5 is a polymer.[4]

SbF5 is a strong Lewis acid, exceptionally so toward sources of F− to give the very stable anion [SbF6]−. The latter reacts with additional SbF5 to give [Sb2F11]−.

In the same way that SbF5 enhances the Brønsted acidity of HF, it enhances the oxidizing Redox describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. This can be either a simple redox process such as the oxidation of carbon to yield carbon dioxide or the reduction of carbon by hydrogen to yield methane (CH4), or it can be a complex process such as the oxidation of sugar in the human body power of F2. This effect is illustrated by the oxidation of oxygen Oxygen , from the Greek roots ὀξύς (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter), is the element with atomic number 8 and represented by the symbol O. It is a member of the chalcogen group on the periodic table, and is a highly reactive nonmetallic period 2 element that:[5]

2 SbF5 + F2 + 2 O2 → 2 [O2]+[SbF6]−

Antimony pentafluoride has also been used in the first discovered chemical reaction that produces fluorine Fluorine is the chemical element with atomic number 9, represented by the symbol F. Fluorine forms a single bond with itself in elemental form, resulting in the diatomic F2 molecule. F2 is a supremely reactive, poisonous, pale, yellowish brown gas. Elemental fluorine is the most chemically reactive and electronegative of all the elements. For gas from fluoride compounds:

4 SbF5 + 2 K2MnF6 → 4 KSbF6 + 2 MnF3 + F2

The driving force for this reaction is the high affinity of SbF5 for F−, which is the same property which recommends the use of SbF5 to generate superacids.

Safety

SbF5 reacts violently with many compounds, often releasing dangerous hydrogen fluoride Hydrogen fluoride is a chemical compound with the formula HF. It is the principal industrial source of fluorine, often in the aqueous form as hydrofluoric acid, and thus is the precursor to many important compounds including pharmaceuticals and polymers . HF is widely used in the petrochemical industry and a component of many superacids. HF boils. It is also corrosive to the skin.

References

  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0070494398
  2. ^ Olah, G. A.; Prakash, G. K. S.; Wang, Q.; Li, X.-y."Antimony(V) Fluoride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
  3. ^ Edwards, A. J.; Taylor, P. "Crystal structure of Antimony Pentafluoride" Journal of the Chemical Society, Chemical Communications 1971, pp. 1376-7.doi A digital object identifier is a character string used to uniquely identify an electronic document or other entity. The DOI for a document remains fixed over the lifetime of the document, unlike URLs which can change when a publisher of online content changes its web server's file structure, and the DOI System provides a mechanism for locating an:10.1039/C29710001376
  4. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  5. ^ Shamir, J.; Binenboym, J. "Dioxygenyl Salts" Inorganic Syntheses, 1973, XIV, 109-122. ISSN An International Standard Serial Number is a unique eight-digit number used to identify a print or electronic periodical publication. The ISSN system was adopted as international standard ISO 3297 in 1975[citation needed]. The ISO subcommittee TC 46/SC 9 is responsible for the standard 0073-8077

External links

Antimony Antimony [note 1] is a chemical element with the symbol Sb (Latin: stibium, meaning "mark") and atomic number 51. A metalloid, antimony has four allotropic forms. The stable form of antimony is a blue-white metalloid. Yellow and black antimony are unstable non-metals. Antimony is used in electronics and flame-proofing, in paints, rubber, compounds

SbBr3 · Sb(C2H3O3)2 · SbCl3 · SbCl5 · SbF3 · SbF5 · SbI3 · Sb2O4 Antimony tetroxide is an inorganic compound with the formula Sb2O4. This material, which exists as the mineral stibiconite , is white but reversibly yellows upon heating. The material, with empirical formula SbO2, is called antimony tetroxide to signify the presence of two kinds of Sb centers · Sb2S5 · Sb2Se3

Categories: Superacids | Antimony compounds | Fluorides Categories: Salts | Halides | Fluorine compounds

 

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