Question

Describe the discovery of the first true noble-gas compound.

Short answer

The first true noble-gas compound, xenon hexafluoroplatinate, was synthesized by British chemist Neil Bartlett in 1962. This discovery overturned the long-held belief that noble gases, due to their full valence electron shells, were inert and incapable of forming compounds.

Step-by-step solution

Background

Up until the mid 20th century, noble gases were considered inert and incapable of forming compounds due to their full valence electron shells. This belief was widely held in the field of chemistry.

Neil Bartlett's Discovery

In 1962, the British chemist Neil Bartlett discovered that the noble gas xenon can in fact form compounds. His work was motivated by the observation that platinum hexafluoride could oxidize molecular oxygen to \( O_2^{+} \), implying that the ionization energy of \( O_2 \) is lower or equal to that of platinum hexafluoride.

Forming Xenon Hexafluoroplatinate

Bartlett postulated that xenon should also react with platinum hexafluoride due its ionization energy being almost identical to that of \( O_2 \). True to his hypothesis, when he combined xenon and platinum hexafluoride, they reacted to form xenon hexafluoroplatinate, \( XePtF_6 \), marking the first successful formation of a true noble-gas compound.

Key concepts

Neil Bartlett

Neil Bartlett was a groundbreaking chemist who changed the way we understand noble gases. Up until his work, noble gases were considered completely inert. This meant they were thought incapable of forming any chemical bonds or compounds due to their full valence electron shells.
Bartlett's curiosity led him to challenge this belief. He observed the behavior of platinum hexafluoride, which could oxidize molecular oxygen to form positive ions. This observation suggested that other elements, even those previously deemed non-reactive like xenon, could potentially form compounds under the right conditions. His revolutionary experiment laid the groundwork for modern research into noble gases.

Xenon

Xenon is a noble gas, positioned in Group 18 of the periodic table. Like other noble gases, it has a full valence shell of electrons which makes it stable and resistant to reacting with other elements. However, xenon's large atomic size and higher atomic number meant it had slightly different properties compared to lighter noble gases, like helium or neon.
Neil Bartlett's experiment demonstrating that xenon can react was groundbreaking. By showing xenon's potential to form chemical compounds, Bartlett opened the door to the possibility of noble gas chemistry, which was once thought impossible. This discovery has since led to the synthesis of other xenon compounds, expanding the knowledge of rich xenon-based chemistry.

Platinum Hexafluoride

Platinum hexafluoride ( PtF_6 ) is a powerful oxidizing agent. It is known for its ability to oxidize oxygen molecules to produce positive ions. This property caught Neil Bartlett's attention when he realized that the ionization potential of a molecular oxygen ion was comparable to that of xenon.
This realization led Bartlett to hypothesize that platinum hexafluoride might also oxidize xenon, despite its status as a noble gas. The experiment utilizing platinum hexafluoride provided a key piece of evidence that demonstrated the potential for xenon to react, and it was central to creating the first noble-gas compound.

Xenon Hexafluoroplatinate

Xenon hexafluoroplatinate ( XePtF_6 ) was the first confirmed noble-gas compound, synthesized as a result of Neil Bartlett's pioneering work. When xenon gas was exposed to platinum hexafluoride, the two reacted to form this novel compound. The creation of XePtF_6 proved that under certain conditions, even noble gases could indeed form stable compounds.
This discovery changed the long-held perception that noble gases were chemically inert. It opened up new areas of research in chemistry, leading to many novel noble-gas compounds with potential applications in fields like electronics and lighting. Bartlett's work not only revealed the reactive potential of xenon but also inspired further exploration into the applications of such compounds.