Carboxylic acid catalyzed keto-enol tautomerizations in the gas phase.

(a) Draw the bi-molecular complex (see Figure 2 in the paper) using Avogadro. (b) Optimize the structure at B3LYP/6-31G** level of theory. (c) Prepare an input file for a relaxed scan (same level of theory) of the proton transfer using the modredundant option (check the manual page for opt ). Please include the option maxcyc=8 regarding the optimization. (Hint: which geometrical parameter do you need to describe a linear proton transfer from Oxygen(vinyl alcohol) to Oxygen(formic acid)? ) (d) Determine the transition state of the Keto-Enol tautomerization. Draw a reaction pathway including figures, Zero-point corrected energies and Gibbs free energies.