Hiickel, Erich Armand Arthur Joseph

Hiickel, Erich Armand Arthur Joseph (1896-1980) German physical and theoretical chemist. Hiickel has two main claims to fame. His first is the theory of electrolytes which Peter Debye and he produced in 1923 and which gives a good description of the electrical and thermodynamic properties of dilue electrolytes. His second major work was the application of quantum mechanics to aromatic molecules such as benzene. He used molecular orbital theory to show that in the benzene molecule the electrons in the pi orbitals are spread out directly above and below the ring of carbon atoms, thus making the molecule more stable than it would be if one had alternating double and single bonds. Hiickel started this work in 1930 and soon extended it to predict the Hiickel rule which states that a molecule is aromatic if it has (An + 2) pi electrons. 

Erich Armand Arthur Joseph Hiickel (1896-1980). 40Sumio Iijima (1939- ). 

At this point, the Hiickel approximations are often imposed to simplify Eq. 5.14. These were introduced by the German physicist Erich Armand Arthur Joseph Hiickel (1896-1980). Even though atomic orbitals on neighboring atoms are nonorthogonal (they have nonzero overlap), it is possible to make the approximation that ... 

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