Observing Transition States
Because of the rules of quantum mechanics, the transition state cannot be captured or directly observed; the population at that point is zero. This is sometimes expressed by stating that the transition state has a 'fleeting existence'. However, cleverly manipulated spectroscopic techniques can get us as close as the timescale of the technique will allow us. Femtochemical IR spectroscopy was developed for precisely that reason, and it is possible to probe molecular structure extremely close to the transition point. Often along the reaction coordinate reactive intermediates are present not much lower in energy from a transition state making it difficult to distinguish between the two.
Read more about this topic: Transition State
Famous quotes containing the words observing, transition and/or states:
“We were observing once to Mr. [Samuel] Crisp that the good and the agreeable were seldom united—”Ay begad,” cried he, “’tis rare enough to meet with the one or the other.””
—Frances Burney (1752–1840)
“Power ceases in the instant of repose; it resides in the moment of transition from a past to a new state, in the shooting of the gulf, in the darting to an aim.”
—Ralph Waldo Emerson (1803–1882)
“[N]o combination of dictator countries of Europe and Asia will halt us in the path we see ahead for ourselves and for democracy.... The people of the United States ... reject the doctrine of appeasement.”
—Franklin D. Roosevelt (1882–1945)