Xenon hexafluoroplatinate
Encyclopedia
Xenon hexafluoroplatinate is the name of the product of the reaction of platinum hexafluoride
and xenon
, in an experiment that proved the chemical reactivity of the noble gas
es. This experiment was performed by Neil Bartlett at the University of British Columbia
, who formulated the product as "Xe+[PtF6]−", although subsequent work suggests that Bartlett's product was probably a mixture and did not in fact contain this specific salt.
and platinum hexafluoride
(PtF6) as gaseous solution
s in SF6
. The reactants are combined at 77K
and slowly warmed, to allow for a controlled reaction.
and would dimerize or abstract an F atom to give XeF+. Thus, Bartlett discovered that Xe
undergoes chemical reactions, but the nature of his initial mustard yellow product is complex. Further work indicates that Bartlett's product probably contained [XeF+][PtF5]−, [XeF+][Pt2F11]−, and [Xe2F3+][PtF6−]. The title "compound" is a salt, consisting of an octahedral anionic fluoride
complex of platinum
and various xenon cations.
It has been proposed that the platinum fluoride forms a negatively charged polymer
ic network with xenon or xenon fluoride cations held in its instices
. A preparation of "XePtF6" in HF
solution results in a solid which has been characterized as a [PtF5−]n polymeric network associated with XeF+. This result is evidence for such a polymeric structure of xenon hexafluoroplatinate.
hexafluoroplatinate, O2+[PtF6]−. Bartlett noticed that the ionization energy for O2 (1175 kJ mol−1) was very close to the ionization energy for Xe (1170 kJ mol−1). He then asked his colleagues to give him some xenon "so that he could try out some reactions", whereupon he established that xenon indeed reacts with PtF6. Although, as discussed above, the product was probably a mixture of several compounds, Bartlett's work was the first proof that compounds could be prepared from a noble gas
. His discovery illustrates that the finding of new chemical methods often lead initially to impure products. Since Bartlett's observation, many well-defined compounds of xenon have been reported including XeF2
, XeF4
, and XeF6
.
Platinum hexafluoride
Platinum hexafluoride is the chemical compound with the formula PtF6. It is a dark-red volatile solid that forms a red gas. The compound is a unique example of platinum in the +6 oxidation state...
and xenon
Xenon
Xenon is a chemical element with the symbol Xe and atomic number 54. The element name is pronounced or . A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts...
, in an experiment that proved the chemical reactivity of the noble gas
Noble gas
The noble gases are a group of chemical elements with very similar properties: under standard conditions, they are all odorless, colorless, monatomic gases, with very low chemical reactivity...
es. This experiment was performed by Neil Bartlett at the University of British Columbia
University of British Columbia
The University of British Columbia is a public research university. UBC’s two main campuses are situated in Vancouver and in Kelowna in the Okanagan Valley...
, who formulated the product as "Xe+[PtF6]−", although subsequent work suggests that Bartlett's product was probably a mixture and did not in fact contain this specific salt.
Preparation
"Xenon hexafluoroplatinate" is prepared from xenonXenon
Xenon is a chemical element with the symbol Xe and atomic number 54. The element name is pronounced or . A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts...
and platinum hexafluoride
Platinum hexafluoride
Platinum hexafluoride is the chemical compound with the formula PtF6. It is a dark-red volatile solid that forms a red gas. The compound is a unique example of platinum in the +6 oxidation state...
(PtF6) as gaseous solution
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
s in SF6
Sulfur hexafluoride
Sulfur hexafluoride is an inorganic, colorless, odorless, and non-flammable greenhouse gas. has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule. Typical for a nonpolar gas, it is poorly soluble in water but soluble in...
. The reactants are combined at 77K
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
and slowly warmed, to allow for a controlled reaction.
Structure
The structure of "xenon hexafluoroplatinate" is probably not Xe+[PtF6]−. The main problem with this formulation is "Xe+", which would be a radicalRadical (chemistry)
Radicals are atoms, molecules, or ions with unpaired electrons on an open shell configuration. Free radicals may have positive, negative, or zero charge...
and would dimerize or abstract an F atom to give XeF+. Thus, Bartlett discovered that Xe
Xenon
Xenon is a chemical element with the symbol Xe and atomic number 54. The element name is pronounced or . A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts...
undergoes chemical reactions, but the nature of his initial mustard yellow product is complex. Further work indicates that Bartlett's product probably contained [XeF+][PtF5]−, [XeF+][Pt2F11]−, and [Xe2F3+][PtF6−]. The title "compound" is a salt, consisting of an octahedral anionic fluoride
Fluoride
Fluoride is the anion F−, the reduced form of fluorine when as an ion and when bonded to another element. Both organofluorine compounds and inorganic fluorine containing compounds are called fluorides. Fluoride, like other halides, is a monovalent ion . Its compounds often have properties that are...
complex of platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
and various xenon cations.
It has been proposed that the platinum fluoride forms a negatively charged polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
ic network with xenon or xenon fluoride cations held in its instices
Interstitial defect
Interstitials are a variety of crystallographic defects, i.e. atoms which occupy a site in the crystal structure at which there is usually not an atom, or two or more atoms sharing one or more lattice sites such that the number of atoms is larger than the number of lattice sites.They are generally...
. A preparation of "XePtF6" in HF
Hydrogen fluoride
Hydrogen fluoride is a chemical compound with the formula HF. This colorless gas 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...
solution results in a solid which has been characterized as a [PtF5−]n polymeric network associated with XeF+. This result is evidence for such a polymeric structure of xenon hexafluoroplatinate.
History
In 1962, Neil Bartlett discovered that a mixture of platinum hexafluoride gas and oxygen formed a red solid. The red solid turned out to be dioxygenylDioxygenyl
The dioxygenyl ion, O2+, is a rarely encountered oxycation in which both oxygen atoms have a formal oxidation state of +½. It is formally derived from oxygen by the removal of an electron:...
hexafluoroplatinate, O2+[PtF6]−. Bartlett noticed that the ionization energy for O2 (1175 kJ mol−1) was very close to the ionization energy for Xe (1170 kJ mol−1). He then asked his colleagues to give him some xenon "so that he could try out some reactions", whereupon he established that xenon indeed reacts with PtF6. Although, as discussed above, the product was probably a mixture of several compounds, Bartlett's work was the first proof that compounds could be prepared from a noble gas
Noble gas
The noble gases are a group of chemical elements with very similar properties: under standard conditions, they are all odorless, colorless, monatomic gases, with very low chemical reactivity...
. His discovery illustrates that the finding of new chemical methods often lead initially to impure products. Since Bartlett's observation, many well-defined compounds of xenon have been reported including XeF2
Xenon difluoride
Xenon difluoride is a powerful fluorinating agent with the chemical formula , and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture sensitive. It decomposes on contact with light or water vapour. Xenon difluoride is a dense, white crystalline solid. It...
, XeF4
Xenon tetrafluoride
Xenon tetrafluoride is a chemical compound with chemical formula . It was the first discovered binary compound of a noble gas. It is produced by the chemical reaction of xenon with fluorine, , according to the chemical equation:...
, and XeF6
Xenon hexafluoride
Xenon hexafluoride is a noble gas compound with the formula XeF6 and the highest of the three binary fluorides of xenon, the other two being XeF2 and XeF4. All are exergonic and stable at normal temperatures. XeF6 is the strongest fluorinating agent of the series...
.