Journal ArticleDOI
Observation of conformation-specific pathways in the photodissociation of 1-iodopropane ions
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It is shown that the kinetic energy released during the photodissociation of 1-iodopropane ions depends strongly on the conformation of the ions, suggesting that the well-known concept of conformation selection forms the basis of a simple scheme for reaction control.Abstract:
Many molecules can rotate freely around single bonds and thereby interconvert between different conformations, such as gauche and anti 1,2-disubstituted ethane, a classic example of conformational isomerism1,2,3. Even though rotation occurs rapidly at room temperature, the product selectivity seen in some reactions has been explained by conformation-dependent reaction mechanisms4,5: if reactant molecules differing only in their conformation are located at different positions on the reaction path, they may undergo different reactions. But a direct verification of this effect is difficult, because the energy barrier separating conformational isomers is so low that under ambient conditions reactants with more than one conformation will be present1. But by using temperatures low enough to suppress the interconversion between different conformations, gauche-1-iodopropane ions and anti-1-iodopropane ions have been selectively generated6. Here we show that the kinetic energy released during the photodissociation of 1-iodopropane ions depends strongly on the conformation of the ions. Thermodynamic arguments and ab initio calculations indicate that this difference in kinetic energy release results from differences in the reaction mechanism, with gauche-1-iodopropane ions forming 2-propyl ions and anti-1-iodopropane ions forming protonated cyclopropane ions. These findings suggest that the well-known concept of conformation selection forms the basis of a simple scheme for reaction control, thus providing in some cases an attractive alternative for more involved schemes that utilize the phase and pulse shape of laser beams to control chemical reactions7,8,9,10.read more
Citations
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Journal ArticleDOI
Specific Chemical Reactivities of Spatially Separated 3-Aminophenol Conformers with Cold Ca+ Ions
TL;DR: The approach demonstrates the possibility of controlling reactivity through selection of conformational states and finds a twofold larger rate constant for the cis compared with the trans conformer (differentiated by the O–H bond orientation).
Journal ArticleDOI
Spatially-controlled complex molecules and their applications
TL;DR: In this paper, the use of inhomogeneous electric fields for the manipulation of neutral molecules in the gas-phase is described, i.e. for the separation of complex molecules according to size, structural isomer, and quantum state.
Journal ArticleDOI
Conformationally Controlled Chemistry: Excited-State Dynamics Dictate Ground-State Reaction
Myung Hwa Kim,Myung Hwa Kim,Lei Shen,Hongli Tao,Todd J. Martínez,Arthur G. Suits,Arthur G. Suits +6 more
TL;DR: Ab initio multiple spawning dynamical calculations suggest that distinct ultrafast dynamics in the excited state deposit each conformer in isolated regions of the ground-state potential energy surface, and, from these distinct regions, conformer interconversion does not effectively compete with dissociation.
Journal ArticleDOI
From Roaming Atoms to Hopping Surfaces: Mapping Out Global Reaction Routes in Photochemistry
TL;DR: This work has developed an efficient computational method, called the global reaction route mapping (GRRM) strategy, that allows a theoretical exploration of ground- and excited-state PESs and their crossing seams in an automatic manner and summarizes approaches and examples of their application together with newly determined chemical insights.
Journal ArticleDOI
Effects of Microsolvation on the Structures and Reactions of Neutral and Zwitterion Alanine: Computational Study
Doo-Sik Ahn,Sung-Woo Park,In-Sun Jeon,Min-Kyung Lee,Nam Hee Kim,and Young-Hwa Han,Sungyul Lee +6 more
TL;DR: In this paper, the effects of the binding water molecules on the relative thermodynamic stability and the isomerization reaction of alanine are examined, and it is shown that at least two water molecules need to bind to produce the stable alane zwitterion−water cluster in the gas phase.
References
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Book
Stereochemistry of Organic Compounds
TL;DR: Stereochemistry of Alkenes Conformation of Acyclic Molecules Configuration and conformation of cyclic Molecule Stereoselective Synthesis Chiroptical Properties Chirality in Molecules Devoid of Chiral Centres as discussed by the authors.
Journal ArticleDOI
Control of Chemical Reactions by Feedback-Optimized Phase-Shaped Femtosecond Laser Pulses
TL;DR: Tailored femtosecond laser pulses from a computer-controlled pulse shaper were used to optimize the branching ratios of different organometallic photodissociation reaction channels, showing that two different bond-cleaving reactions can be selected, resulting in chemically different products.
Book
Thermochemical data of organic compounds
TL;DR: In this paper, the authors describe a simple scheme for predicting unknown values of standard enthalpies of formation from experimental data for approximately 3000 organic compounds of the elements C, H, 0, N, S and halogens.
Journal ArticleDOI
Handbook of He(I) photoelectron spectra of fundamental organic molecules : K. Kimura, S. Katsumata, Y. Achiba, T. Yamazaki and S. Iwata, 1981, Japan Scientific Societies Press, Tokyo, ISBN 4-7622-0263-X and Halsted Press, New York, 268 pp., US $44.95, ISBN 0-470-27200-7.
Journal ArticleDOI
Wavepacket dancing: Achieving chemical selectivity by shaping light pulses
TL;DR: In this article, the Tannor-Rice pump-dump scheme for controlling selectivity of product formation in a chemical reaction is improved by developing a method for optimizing the field of a particular product with respect to the shapes of the pump and dump pulses.