[5][7][8] Klemm refined Eduard Zintl's ideas about the structure of intermetallic compounds and their connections to develop the Zintl-Klemm concept.
[9][10][11] Klemm co-authored one of the ten most-cited papers in the history of the journal Zeitschrift für anorganische und allgemeine Chemie.
[25] In December 1924 Klemm married Lisabeth Herrmann, who had studied chemistry at Danzig (Gdansk) and at Breslau University with Heinrich Biltz.
[25][26] As of 1 April 1933, Klemm became a full professor and head of the Department of Inorganic Chemistry at the Technische Hochschule Danzig.
Klemm replaced Hans Joachim von Wartenberg,[22] who had taught at the Technische Hochschule Danzig from 1913 to 1932 and served in several senior positions including head of the Department of Inorganic Chemistry.
[31]: 313 Following the Invasion of Poland which began 1 September 1939, the Free City of Danzig was annexed by Germany, and anti-Jewish measures escalated.
[33] In a letter to the editorial staff of Chemische Berichte in June 1942 Klemm argued that contributions from chemist Georg-Maria Schwab and other "non-Aryan" authors should not appear in German chemical journals.
[37] Approximately 500 books and pieces of equipment and 300 staff and family members sailed on the ship Deutschland on 27 January 1945 bound for Kiel.
[38] Klemm was the lead author for the preparation and publication of the six inorganic chemistry volumes of the FIAT review of German science, 1939-1946 (1948-1949).
[41] The Institute of Inorganic Chemistry at the University of Kiel has a collection of correspondence and other papers dating from 1947 through the 1960s, relating to Wilhelm Klemm and his successor, Robert Juza.
[3][2] By 1951, the Allied Powers were lifting reemployment restrictions against Nazi party members, and it became easier for academics to find or change positions.
[41][22] At a very early stage he recognized the importance of physical methods including crystal structure analysis using X-ray diffraction and magnetochemical measurements for the investigation of solids.
[41][22][44] His work on the properties of rare elements such as gallium, germanium, indium, rhenium and related compounds was considered authoritative.
He also examined indium, gallium, germanium, and rhenium, and rare earth elements, determining their heats of formation and studying their reactivity with ammonia.
1.73 Bohr magnetons) was found to be inconsistent with the structure determination proposed by Franz Hein for penta-, tetra- and triphenylchromium compounds.
They played around with chemical structures like J. S. Bach made musical variations on a theme in The Art of Fugue - Rudolf Hoppe[49] Klemm's research led to the identification of systematic relationships among the elements of the periodic system.
It also led to a new method for classifying rare earths based on the stability of both completely filled and "half-filled" electrons which could be applied to both ions and metals.
[5] Klemm identified unusual oxidation states in oxo- and fluoro- complexes and refined the ideas of Eduard Zintl on the structure of intermetallic compounds to develop the Zintl-Klemm concept.
[3] Klemm was co-editor of Zeitschrift für anorganische und allgemeine Chemie (the journal for inorganic and general chemistry) from 1939 to 1965.
[5][12] From 1945 onwards, his central tasks were to reestablish teaching and research in Kiel (1947-1951) and in Münster (1951-) and to help reconstruct chemical institutions at the national and international levels.
[57] On 8 July 1977 Wilhelm and Lina Klemm signed a will describing their intention to use the revenue from the eventual sale of their home at Theresiengrund 22 for scholarships for students to travel and present their research internationally.