In a molecule, strain energy is released when the constituent atoms are allowed to rearrange themselves in a chemical reaction or a change of chemical conformation in a way that:
- angle strain,
- torsional strain,
- ring strain and/or steric strain,
- Allylic strain, and
- pentane interference
are reduced. The external work done on an elastic member in causing it to distort from its unstressed state is transformed into strain energy which is a form of potential energy. The strain energy in the form of elastic deformation is mostly recoverable in the form of mechanical work.
For example, the heat of combustion of cyclopropane (696 kJ/mol) is higher than that of propane (657 kJ/mol) per methylene unit. Compounds with unusually large strain energy include tetrahedranes, propellanes, cubanes, fenestranes and cyclophanes.
Famous quotes containing the words strain and/or energy:
“You blind guides! You strain out a gnat but swallow a camel!”
—Bible: New Testament, Matthew 23:24.
“The very presence of guilt, let alone its tenacity, implies imbalance: Something, we suspect, is getting more of our energy than warrants, at the expense of something else, we suspect, that deserves more of our energy than we’re giving.”
—Melinda M. Marshall (20th century)