Pitzer tension

Pitzer voltage is made after the chemist Kenneth Sanborn Pitzer (1914-1997, USA named) Ring voltage of a molecule formed by Van der Waals repulsion of eclipsed and gauche arranged substituents of adjacent atoms is induced (including hydrogen atoms). This is about 17-21 kJ / mol (4-5  kcal / mol) per ecliptic interaction  .

Due to the Pitzer voltage z. B. Cyclopentane not planar . Although it would be almost free of valence angle stress as a flat molecule with a CC bond angle of 108 ° , it prefers a kinked envelope shape.

In cyclic compounds , the Pitzer tension represents part of the total ring tension , the other components of which are the Baeyer tension or valence angle tension (mainly represented in the three-ring and four-ring), the Newman tension (1.5 repulsion of non-hydrogen atoms) and the Prelog tension or transannular interaction (especially with larger rings, maximum with ten-rings).

See also

• Baeyer tension
• Newman tension
• Prelog tension

literature

• Manussawee Hengsuwan and Ann-Christin Pöppler: Synthesis of five, six and seven rings . (Lecturer: Daniel B. Werz) University of Göttingen, 2007
• Adalbert Wollrab: Organic Chemistry. Google book search. Pp. 154, 155.
• Jan Bulle and Aloys Huttermann: The basic knowledge of organic chemistry. Google book search. Pp. 113, 114.

Web links

• Essentials 4: Cycloalkanes (PDF file, 128 kB) at the University of Düsseldorf