Specific Chemical Reactivities of Spatially Separated 3-Aminophenol Conformers with Cold Ca+ Ions

• Published in: Science (American Association for the Advancement of Science) Vol. 342; no. 6154; pp. 98 - 101
• Main Authors: CHANG, Yuan-Pin, DŁUGOŁECKI, Karol, KÜPPER, Jochen, RÖSCH, Daniel, WILD, Dieter, WILLITSCH, Stefan
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 04.10.2013; The American Association for the Advancement of Science
• Subjects: Bibliometrics. Scientometrics; Bibliometrics. Scientometrics. Evaluation; Chemical reactions; Covalent bonds; Electric fields; Exact sciences and technology; Flexibility; Information and communication sciences; Information science. Documentation; Library and information science. General aspects; Molecular beams; Molecular chemistry; Orientation; Rotational; Sciences and techniques of general use
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1242271

Many molecules exhibit multiple rotational isomers (conformers) that interconvert thermally and are difficult to isolate. Consequently, a precise characterization of their role in chemical reactions has proven challenging. We have probed the reactivity of specific conformers by using an experimental technique based on their spatial separation in a molecular beam by electrostatic deflection. The separated conformers react with a target of Coulomb-crystallized ions in a trap. In the reaction of Ca(+) with 3-aminophenol, we find a twofold larger rate constant for the cis compared with the trans conformer (differentiated by the O-H bond orientation). This result is explained by conformer-specific differences in the long-range ion-molecule interaction potentials. Our approach demonstrates the possibility of controlling reactivity through selection of conformational states.