A DFT study of the hydrolysis of hydantoin

• Published in: International Journal of Chemical Kinetics
• Main Authors: Yamabe, Shinichi, Tsuchida, Noriko, Yamazaki, Shoko
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2019
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1002/kin.21312; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fkin.21312; https://onlinelibrary.wiley.com/doi/pdf/10.1002/kin.21312; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/kin.21312

Abstract Density functional theory (DFT) calculations were made on the hydrolysis of hydantoin (2,4‐imidazolidinedione). In the neutral hydrolysis, reacting systems composed of hydantoin and (H 2 O) n with n = 1+3, 2+3, 3+3, and 4+3 were adopted. Three water molecules (“+3”) participate in the in‐plane hydrogen‐bond circuit, and the n –3 = 1, 2, 3 or 4 water cluster works for the out‐of‐plane nucleophilic attack onto the carbonyl carbon of hydantoin. Transition states (TSs) involving bond interchanges prompted by proton transfers were determined. The reaction path with n = 3+3 containing N ‐carbamoyl glycine, N ‐carboxy glycine and three tetrahedral intermediates was found to be most likely. In the acid‐catalyzed hydrolysis, a reacting system composed of hydantoin and H 3 O + (H 2 O) 7 was employed. Ten TSs and nine intermediates were obtained. N ‐carbamoyl glycine and N ‐carboxy glycine were confirmed to be detectable stable species. The product consists of glycine, carbonic acid (not CO 2 ), NH 4 + , and (H 2 O) 5 . It has the exothermic energy, whereas the product in the neutral hydrolysis is of the endothermic one for all n values. For both neutral ( n = 3+3) and acid‐catalyzed hydrolyses, the rate‐determining steps were calculated to be for formation of the tetrahedral intermediate, HOOC‐CH 2 ‐NH‐C(OH) 2 NH 2 . The pattern of proton transfers along hydrogen bonds was carefully investigated.