티오아세트 아미드(TAA)의 형태와 양성자화된 TAA의 형태를 CNDO/2 방법으로 결정하고 물분자 접근시의 분자간 상호작용 에너지를 계산하였다. 양성자는 S원자보다는 N원자에 첨가되는 것이 안정하며 또 물분자가 접근 할때의 안정화에너지도 N-양성자화된 TAA에서 컸다. 이때는 CS결헙의 LUMO의 강한 반결합성 때문에 우선적인 CS 절단으로 반응이 진행되며 orbital controlled 반응 임을 알았다.
Conformations of thioacetamide (TAA) and its protonated form were determined using the CNDO/2 method, and the intermolecular interaction energies between the protonated TAA and water were calculated. It was found that: (1) protonation occurs preferentially on the N rather than on the S atom, (2) the stabilization energy of intermolecular perturbation between the protonated TAA and water was also large for the N-protonated TAA. This causes preferential CS bond cleavage due to large antibonding nature of the CS bond in the LUMO, and leads to an orbital controlled reaction.
