Benzene and its structure
After 90 years, scientists reveal the structure of benzene 1
Article abstract
The fundamental electronic structure of benzene was illustrated by a recent collaboration between scientists. By
applying a complex algorithm-based method called dynamic Voronoi Metropolis sampling (DVMS) to benzene
molecules, their wavefunctions were mapped across 126 dimensions, in which benzene’s electrons exist. The
algorithm divided the dimensional space into “tiles” corresponding to a permutation of electron positions, which
helped scientists observe a link between spin and the type of bonding. Electrons with up spin formed double bonds
and those with down spin formed single bonds, making benzene more stable by reducing the energy of the
molecule. Most importantly, these findings can be used in improving technological developments in which
benzene is used, including solar cells, LEDs and telecommunications technology. The algorithm can also be applied
to different contexts such as staff rostering and kidney exchange programmes.
Kekulé’s model of benzene2
Kekulé suggested that benzene has a cyclic ring structure with alternating single and double Carbon-Carbon bonds.
The model was accepted for many years but new evidence contradicted this structure, leading to the proposal of a
new model by Pauling, which resulted in the present model of benzene with a ring of delocalised electrons.
(Stephenson, 2012)
Evidence that enabled scientists to suggest a new structure of benzene
1. X-ray diffraction
- X-ray diffraction is a technique for analysing the atomic or molecular structure of materials. 3
- Single C-C bond lengths in cyclohexene were measured to be 0.154nm using single crystal X-ray diffraction
and double C=C bonds lengths were measured to be 0.133nm.
- Cyclohexene was used as it has a similar structure to Kekulé’s model of benzene.
1
https://phys.org/news/2020-03-years-scientists-reveal-benzene.html
2
https://www.epmagazine.org/storage/164/benzene.aspx
3
https://www.scimed.co.uk/education/what-is-x-ray-diffraction-xrd/
After 90 years, scientists reveal the structure of benzene 1
Article abstract
The fundamental electronic structure of benzene was illustrated by a recent collaboration between scientists. By
applying a complex algorithm-based method called dynamic Voronoi Metropolis sampling (DVMS) to benzene
molecules, their wavefunctions were mapped across 126 dimensions, in which benzene’s electrons exist. The
algorithm divided the dimensional space into “tiles” corresponding to a permutation of electron positions, which
helped scientists observe a link between spin and the type of bonding. Electrons with up spin formed double bonds
and those with down spin formed single bonds, making benzene more stable by reducing the energy of the
molecule. Most importantly, these findings can be used in improving technological developments in which
benzene is used, including solar cells, LEDs and telecommunications technology. The algorithm can also be applied
to different contexts such as staff rostering and kidney exchange programmes.
Kekulé’s model of benzene2
Kekulé suggested that benzene has a cyclic ring structure with alternating single and double Carbon-Carbon bonds.
The model was accepted for many years but new evidence contradicted this structure, leading to the proposal of a
new model by Pauling, which resulted in the present model of benzene with a ring of delocalised electrons.
(Stephenson, 2012)
Evidence that enabled scientists to suggest a new structure of benzene
1. X-ray diffraction
- X-ray diffraction is a technique for analysing the atomic or molecular structure of materials. 3
- Single C-C bond lengths in cyclohexene were measured to be 0.154nm using single crystal X-ray diffraction
and double C=C bonds lengths were measured to be 0.133nm.
- Cyclohexene was used as it has a similar structure to Kekulé’s model of benzene.
1
https://phys.org/news/2020-03-years-scientists-reveal-benzene.html
2
https://www.epmagazine.org/storage/164/benzene.aspx
3
https://www.scimed.co.uk/education/what-is-x-ray-diffraction-xrd/
