Theoretical study on formation reaction of lutidine derivative.

Abstract

The reaction path of the acetyl acetone method (or Nash reagent), from acetyl acetone (pentane-2,4-dione) to lutidine derivative, that is the reaction to measure the concentration of the formaldehyde and became very important in these days, was calculated at the HF/3-21G + ZPC level（ZPC=zero point energy correction), and MP2/6-31G** + ZPC level. In order to study the difference of the reaction environment, as a model for porous glass, H₂Si=O and (OH)₂Si=O are added to the systems, however, the silicon atom makes chemical bonds or strong complex with the oxygen atom of FLUORAL-P. We also found the formation of the chemical bond decreases the activation energy of a H₂O elimination reaction. On the other hands, the carbon analogous H₂C=O and water molecule H₂O do not make a chemical bond with FLUORAL-P and the activation energy of a H₂O elimination reaction does not decrease. Difference between the carbon and silicon atom is considered to be the difference of their LUMO levels.