Comparative MO investigation of hindered rotation and thermal decomposition of carbamates and thiocarbamates.
Investigation of hindered rotation in carbamates reveals the high flexibility and ionic character of the CN bond as compared to common amides. This flexibility decreases in the case of thiocarbamates. The mechanism of activation of carbamates has been explored. Computations have proven the possibility of formation of an intramolecular H-bond in carbamates and thiocarbamates. This intramolecular H-bond is formed immediately after protonation of the carbamate. The possibility of formation of zwitterions as intermediates in the decomposition of carbamic and dithiocarbamic acids is discussed.
Hilal
R
R
Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt.
Hamed
M M
MM
Moustafa
H
H