Rudolf Hoppe (29 October 1922 – 24 November 2014), a German chemist, discovered the first covalent

noble gas compound In chemistry, noble gas compounds are chemical compounds that include an element from the noble gases, group 8 or 18 of the periodic table. Although the noble gases are generally unreactive elements, many such compounds have been observed, parti ...

Academic career

Hoppe studied chemistry at the Christian-Albrechts-

University of Kiel Kiel University, officially the Christian Albrecht University of Kiel, (, abbreviated CAU, known informally as Christiana Albertina) is a public research university in the city of Kiel, Germany. It was founded in 1665 as the ''Academia Holsator ...

and was awarded his doctorate at the Westfälische Wilhelms-

University of Münster The University of Münster (, until 2023 , WWU) is a public research university located in the city of Münster, North Rhine-Westphalia in Germany. With more than 43,000 students and over 120 fields of study in 15 departments, it is Germany's ...

in 1954 under the supervision of Wilhelm Klemm. He also got his habilitation degree in Münster and gained a professorship for inorganic chemistry in 1958. In 1965, Hoppe accepted an offer for the chair of inorganic and analytic chemistry at the

Justus Liebig University Giessen University of Giessen, official name Justus Liebig University Giessen (), is a large public research university in Giessen, Hesse, Germany. It is one of the oldest institutions of higher education in the German-speaking world. It is named after ...

, which he kept until his retirement in 1991.

Scientific research

In Münster

Hoppe became famous through his synthesis of the stable noble gas compound XeF₂ (

xenon difluoride Xenon is a chemical element; it has symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as th ...

), reported in November 1962. His work followed the previous synthesis of by xenon hexafluoroplatinate by Neil Bartlett, in an experiment run on March 23, 1962 and reported in June of that year. Until then, everyone had assumed that compounds of such kind would not exist, the reason being, first, unsuccessful experiments attempting to synthesize such noble gas compounds and, second, the concept of the "closed octet of electrons", according to which noble gases would not participate in chemical reactions. Through the properties of the

interhalogen compound In chemistry, an interhalogen compound is a molecule which contains two or more different halogen atoms (fluorine, chlorine, bromine, iodine, or astatine) and no atoms of elements from any other group. Most interhalogen compounds known are binar ...

s it had become obvious that noble gas fluorides were the only accessible ones. Since 1949/50, a research group in Münster had carried out in-depth discussions on the possibility of the formation and the properties of xenon fluorides. This research group was convinced, already in 1951, that XeF₄ and XeF₂ should be thermodynamically stable against the decomposition into the elements. For a long time it was planned to occasionally perform synthetic experiments targeted at the xenon fluorides. Technical and conceptional difficulties, however, interfered in Münster. On the one hand, xenon was not accessible in sufficient purity; on the other hand, the researchers believed that only pressure syntheses would be successful, for which steel bottles with compressed F₂ were needed. Since 1961, those F₂-pressure cylinders had been promised by American friends but the transfer could not take place until 1963 because the valves of non-standard U.S. pressure cylinders were not allowed in Germany and vice versa. Nevertheless, Hoppe’s research group was able to generate XeF₂ in the form of transparent crystals in early 1962. To do so, they let electric sparks impact on xenon-fluorine mixtures. Neil Bartlett tried a similar experiment for the first time in the USA on August 2, 1962. After a few days, he gained

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: : Xe + 2 → This reaction is exothermic, rele ...

, XeF₄.

In Gießen

In Gießen, Hoppe continued his extensive research in the field of solid state chemistry with a focus on the synthesis and characterization of oxo- and fluorometalates of the alkali metals. During his research he published over 650 articles in international and national peer-review journals. In addition, he had been the scientific editor for the German Journal of Inorganic and General Chemistry (Zeitschrift für Anorganische und Allgemeine Chemie).

Teachings

As a professor, Prof. Hoppe taught many young students the fundamentals of chemistry and other more specific topics. In addition, 114 doctoral candidates earned their Ph.D. with Hoppe as their supervisor.

Other activities

Hoppe was a great pet lover and was known to be a supporter of zoological gardens. He died at the age of 92 on 24 November 2014.

Honors

*Honorary doctorate of the Christian Albrechts University of Kiel (1983) as well as of the University of Ljubljana (1990) *Award of the

Göttingen Academy of Sciences and Humanities The Göttingen Academy of Sciences (name since 2023 : )Note that the German ''Wissenschaft'' has a wider meaning than the English "Science", and includes Social sciences and Humanities. is the oldest continuously existing institution among the eig ...

(1963) *Alfred Stock Award of the

German Chemical Society The German Chemical Society () is a learned society and professional association founded in 1949 to represent the interests of German chemists in local, national and international contexts. GDCh "brings together people working in chemistry and th ...

(1974) *Henri Moissan Medal of the

Société chimique de France Groupe Lactalis S.A. (doing business as Lactalis) is a French multinational dairy products corporation, owned by the Besnier family and based in Laval, Mayenne, France. The company's former name was Besnier S.A. Lactalis is the largest dairy pr ...

(1986) *Jozef Stefan Medal of the Jozef Stefan Institute in Ljubljana (1988) * Otto Hahn Award for Chemistry and Physics (1989) as the first representative of inorganic chemistry *

Lavoisier Medal A Lavoisier Medal is an award named and given in honor of Antoine Lavoisier, considered by some to be a father of modern chemistry.

(along with

Derek Barton Sir Derek Harold Richard Barton (8 September 1918 – 16 March 1998) was an English organic chemist and Nobel Prize laureate for 1969. Education and early life Barton was born in Gravesend, Kent, to William Thomas and Maude Henrietta Barton ...

) of the

(1995) Furthermore, Hoppe has been a member of several scientific societies and academies as well as of the

German National Academy of Sciences Leopoldina The German National Academy of Sciences Leopoldina (), in short Leopoldina, is the national academy of Germany, and is located in Halle (Saale). Founded on 1 January 1652, based on academic models in Italy, it was originally named the ''Academi ...

in Halle and of the

Bavarian Academy of Sciences The Bavarian Academy of Sciences and Humanities () is an independent public institution, located in Munich. It appoints scholars whose research has contributed considerably to the increase of knowledge within their subject. The general goal of th ...

and

Austrian Academy of Sciences The Austrian Academy of Sciences (; ÖAW) is a legal entity under the special protection of the Republic of Austria. According to the statutes of the Academy its mission is to promote the sciences and humanities in every respect and in every fi ...

References

*https://web.archive.org/web/20090628130943/http://home.arcor.de/prignitzportal/citizen/seite_hoppe_rudolf.htm *Hoppe, R.; Valence Compounds of the Inert Gases, ''Angewandte Chemie International Edition Engl.'', 1964, ''3'', 538. {{DEFAULTSORT:Hoppe, Rudolf 1922 births 2014 deaths People from Wittenberge 20th-century German chemists Academic staff of the University of Giessen Solid state chemists University of Kiel alumni University of Münster alumni Academic staff of the University of Münster Members of the German National Academy of Sciences Leopoldina Members of the Austrian Academy of Sciences