Xenon hexafluoroplatinum is the first group 0 element discovered by human beingschemical compound(i.e. noble gas compounds), its discovery is of great significance.The discoverer of xenon hexafluoroplatinate was British chemist Neil Bartlett (1932-2008).
In 1916, Walther Kossel speculated that krypton and xenon should be able tofluorineCombine to form a compound.Since then, synthesisNoble gas(then calledinert gas）The challengers of compounds are endless, but many famous chemists, including Otto Ruff, a German chemist who is recognized as the strongest in fluorine chemistry in history, have failed.In 1933, Linus Pauling wonNobel Prize in Chemistry）Prediction of published papers HfourXeOsix、XeFsixAnd KrFsixThe exists of.PaulinePeerDon Yost and Albert Kaye tried to synthesize XeFsixHowever, they were unable to obtain enough products to analyze and prove.
Bartlett's discovery can be described as "unintentionally cutting into willows to create shade".His original subjects were notNoble gas, butplatinumFluoride.Platinum difluoride (PtFtwo）It can react with fluorine gas to produce platinum tetrafluoride (PtFfour）However, Bartlett used a higher temperature when operating the same experiment in 1960, and found that two products would be obtained, one is platinum pentafluoride (PtFfive）In addition, there is also a platinum oxyfluoride, which Bartlett considered to be platinum tetrafluoroxide (PtOFfour）。But the reactants are not only platinum difluoride and fluorine gas?Where does oxygen come from?After careful inspection by Bartlett, it was found that oxygen is composed of fluorine and glass (mainly composed ofsilicon dioxide, i.e. SiOtwo）Reaction.
After more accurate and complete element analysis, Bartlett found that the second product was not PtOFfour, but PtOtwoFsix。In particular, PtF will be obtained by hydrolyzing this platinum salt watersixAnions.Since acid radical is not formed in aqueous solution, there were six fluorine atoms connected to platinum atoms in platinum salt, which means that this salt should be
。Bartlett revised his previously published results in 1962.[1]
It is a very rare cation, because oxygen atoms usually easily get electrons to form anions.But Bartlett's thinking goes beyond that. He sees the possibility behind the experiment: oxygenFirst ionization energy（
）Is 12.2 electron volts (eV, 1eV=96kJ/mol), which is close to the first ionization energy of xenon (12.1 electron volts).This means that if platinum hexafluoride can oxidize oxygen, it should also oxidize xenon to form xenon compounds.He also calculatedLattice energy, if XePtF is generatedsix, whose lattice energy is only less than OtwoPtFsixSmall 41.84kJ/mol.This indicates that XePtF6 should be stable once generated.In June 1962, Bartlett was in EnglandProccedings of the Chemical SocietyAn important short article was published in the magazine, which officially released its own experimental report to the chemical community, and shocked the entire chemical community.He proposed that slowly adding xenon to platinum hexafluoride at low temperature would react to form an orange solid, that is, xenon hexafluoroplatinate (XePtFsix）。This is a historic discovery, and the "noble gas" was renamed as "rare gas".After Bartlett until today, the noble gases of group 0 elementsElement 118Other than Og (鿫鿫), they all have their corresponding compounds. The latest compound is NatwoHe [This compound is similar to an atomic compound. The bond between sodium and helium is extremely weak but can exist under special conditions].[2]
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The research on xenon hexafluoroplatinate is still in progress, and few properties of xenon hexafluoroplatinate have been determined.
Stable at room temperature.
It decomposes rapidly when encountering water and releases gas.Chemical equationFor:
2XePtFsix+6HtwoO==2Xe↑+Otwo↑+2PtOtwo+12HF
As the ratio of platinum hexafluoride to xenon is different, the composition of the product changes in a certain range.Later experiments proved that the chemical formula of xenon hexafluoroplatinate is not so simple, which may include XePtFsixAnd XePtFeleven。
XePtFsixThe valence of each element in is+1,+5 and - 1 respectively.Among them, Pt is in a higher valence state, which is oxidizing, and Xe is oxidizing.
Insoluble in non-polar carbon tetrachloride.This indicates that it may beIonic compound。[2]
Preparation
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Xenon hexafluoroplatinate is composed ofplatinum hexafluoride staySulfur hexafluorideIt is made by oxidizing xenon in gas.The initial temperature of the reaction was 77K, and the temperature gradually increased with the reaction.
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Some people believe that the structure of xenon hexafluoroplatinate may not be "XePtFsix”, because "Xe" is a free radicalDimerization, or seize a fluorine atom to generate XeF.Later research shows that the orange solid is likely to contain XePtF6、XePtFeleven、XetwoPtFsixThe anions are octahedral platinum fluoride ions, and the cations are various xenon containing ions.
stayHydrogen fluorideXenon hexafluoroplatinate prepared in solution contains [PtFfive]N and XeF ions, so it is believed that platinum and fluorine ions are formed in xenon hexafluoroplatinumpolymerizationThe gap is filled with xenon or cations formed by xenon and fluorine.
