Water-Assisted Dissociation Reactions for the Compounds of A(CO)B and A(CO)2B (A, B = H, OH):  A Density Functional Theory Study

• Published in: Journal of the American Chemical Society 1999-05, Vol.121 (17), p.4222-4228
• Main Authors: Lin, Chiu-Ling, Chu, San-Yan
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja982337v

Dissociation reactions of mono- and dicarbonyl compounds, A(CO)B and A(CO)2B (A, B = H, OH), to form CO, CO2, H2O, or H2, were studied theoretically by the B3LYP/6-31G** method. We found that the participation of water can modify the reaction forbiddenness in addition to providing strain relief for the transition structure. It appeared that the water-assisted reactions are more effective for the monocarbonyl series than for the dicarbonyl series. Because the bonding of the hydrogen atom is less directional, the transition structure of a dehydrogenation reaction is less strained and thus receives a less strain relief effect than the dehydration reaction of the same ring size. A substantial increase in asynchronicity between the two leaving groups was observed from the water-free to the water-assisted reactions.