Femtochemistry

Femtochemistry is the area of physical chemistry that studies chemical reactions on extremely short timescales (approximately 10⁻¹⁵ seconds or one femtosecond, hence the name) in order to study the very act of atoms within molecules (reactants) rearranging themselves to form new molecules (products). In a 1988 issue of the journal Science, Ahmed Hassan Zewail published an article using this term for the first time, stating "Real-time femtochemistry, that is, chemistry on the femtosecond timescale...".^[1] Later in 1999, Zewail received the Nobel Prize in Chemistry for his pioneering work in this field showing that it is possible to see how atoms in a molecule move during a chemical reaction with flashes of laser light.^[2]

Application of femtochemistry in biological studies has also helped to elucidate the conformational dynamics of stem-loop RNA structures.^[3][4]

Many publications have discussed the possibility of controlling chemical reactions by this method,^{[clarification needed]} but this remains controversial.^[5] The steps in some reactions occur in the femtosecond timescale and sometimes in attosecond timescales,^[6] and will sometimes form intermediate products. These reaction intermediates cannot always be deduced from observing the start and end products.