MIT chemists characterize a chemical state thought to be unobservable
For the first time, MIT chemists have measured the energy of the transition state of a chemical reaction — a fleeting, unstable state that is a reaction’s point of no return. Chemists have long believed it impossible to experimentally characterize transition states, but the MIT team achieved it by analyzing changes in the patterns of vibrational energy levels in reactants approaching the transition state. “This was supposed to be impossible because of the intrinsic complexity, but we found the magic decoder that enables us to go deeper into this regime,” says Robert Field, the Robert T. Haslam and Bradley Dewey Professor of Chemistry and senior author of the study, which appears in the Dec. 10 online edition of Science. Broken patterns As every freshman chemistry student learns, the transition state of a reaction is the gateway between reactants and products. Most reactions require an input of energy, known as the activation energy, to reach...