1. Bonding of benzene C6H6
Planar cyclic structure
Unpaired e- in p-orbital: overlap to form cloud above & below plane of ring = ring of delocalised e ’s
Equal bond lengths between single/double
Delocalised ring = more stable than theoretical cyclohexa-1,3,5-triene (alternating double bonds)
- enthalpy of hydrogenation: experimental less exothermic than theoretical
- more energy required to break bonds = more stable
- energy spread over larger area – not localised = stable
Planar cyclic structure
Unpaired e- in p-orbital: overlap to form cloud above & below plane of ring = ring of delocalised e ’s
Equal bond lengths between single/double
Delocalised ring = more stable than theoretical cyclohexa-1,3,5-triene (alternating double bonds)
- enthalpy of hydrogenation: experimental less exothermic than theoretical
- more energy required to break bonds = more stable
- energy spread over larger area – not localised = stable
