Engineering reactions in crystalline solids: predicting photochemical decarbonylation from calculated thermochemical parameters.
A detailed thermochemical analysis of the alpha-cleavage and decarbonylation reactions of acetone and several ketodiesters was carried out with the B3LYP/6-31G* density functional method. The heats of formation of several ground-state ketones and radicals were calculated at 298 K to determine bond dissociation energies (BDE) and radical stabilization energies (RSE) as a function of substituents. Results show that the radical-stabilizing abilities of the ketone substituents play a very important role on the thermodynamics of the alpha-cleavage and decarbonylation steps. An excellent correlation between calculated values and previous experimental observations suggests that photochemical alpha-cleavage and decarbonylation in crystals should be predictable from knowledge of excitation energies and the RSE of the substituent.
Campos
Luis M
LM
Department of Chemistry, California State University Dominguez Hills, Carson, CA 90747, USA.
Dang
Hung
H
Ng
Danny
D
Yang
Zhe
Z
Martinez
Hernan L
HL
Garcia-Garibay
Miguel A
MA
D000096:Acetone / Q000737:chemistry; D003460:Crystallization; D004952:Esters / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D010777:Photochemistry; D013816:Thermodynamics
D004952:Esters; D007659:Ketones; D000096:Acetone