Spectroscopic Characterization of Isomerization Transition States 1D MEIP picture (fancy, somehow) Joshua H. Baraban, P. Bryan Changala, Georg Ch. Mellau, John F. Stanton, Anthony J. Merer, and Robert W. Field
S1 C2H2 cis-trans J. H. Baraban, P. B. Changala, G. Ch. Mellau, J. F. Stanton, A. J. Merer, and R. W. Field. Science, 350(6266):1338–1342, 2015.
Excitation in v3 distorts bending polyads Steeves et. al., J. Mol. Spec., 256, 256, 2009.
Quasilinearity Model is a Gaussian bump in a harmonic well, cylindrically symmetric ωeff “dips” at the barrier energy Levels with K≠0 dip less because they avoid the linear geometry Mention HCP work by Child and Jacobson R. N. Dixon. Trans. Faraday Soc., 60:1363–1368, 1964.
Long Range Regimes Harmonic Oscillator LeRoy-Bernstein Morse Oscillator Double Minimum
Barrier Height ETS= 5091 ± 33 cm-1 EOM-CCSDTQ/ANO1: 5105 cm-1 J. H. Baraban, D. A. Matthews, and J. F. Stanton. JCP, 144(11):111102, 2016.
Spectator Modes
S0 HCN - HNC
Transition State Information Quadratic Fit vs. 𝓁: 11.1 ± 0.9 cm-1 Ab initio TS geometry: 12.2 cm-1
Transition State Theory
Transition State Theory Chemistry 101 Reaction Coordinate Transition State Theory “Throughout the 20th century it was a cornerstone of mechanistic analysis that we could never “see” a transition state . . . we remain in the classical situation in which it is experimentally impossible to characterize a transition state.” Anslyn & Dougherty, Modern Physical Organic Chemistry, 2004.
Acknowledgements Field Group Members: Collaborators: Bob Field Bryan Changala Annelise Beck Julia Berk Dr. Adam Steeves Dr. Hans Bechtel Collaborators: Dr. G. Ch. Mellau Prof. J. F. Stanton Prof. A. J. Merer Dr. J. T. Hougen Prof. A. G. Suits Dr. D. A. Matthews Funding DOE NSF GRFP Humboldt Foundation Tony Colombo Prof. Wilton Virgo Barratt Park Dr. Kyle Bittinger Rachel Shaver Monika Ciuba David Grimes Dr. Vladimir Petrovic Yan Zhou Jun Jiang Dr. Kirill Kuyanov Peter Richter Dr. Steve Coy
Effect of Barrier Shape