O—H and C—H bond dissociations in non-phenyl and phenyl groups: A DFT study with dispersion and long-range corrections

Abstract

Hydrogen atom transfer is one important reaction in biological system, in industry, and in atmosphere. The reaction is preluded by hydrogen bond dissociation. To gain a comprehensive understanding on the reaction, it is necessary to investigate how the current computational methods model hydrogen bond dissociation. As a starting point, we utilized density functional theory-based calculations to identify the effect of dispersion and long-range corrections on O-H and C-H dissociations in non-phenyl and phenyl groups. We employed five different methods, namely B3LYP, CAM-B3LYP (with long-range correction), M06-2X, and B3LYP and CAM-B3LYP with the D3 version of Grimme's dispersion. The results showed that for the case of O-H dissociation in two member of phenyl groups, namely phenol and catechol, the dispersion correction's effect was negligible, but the long-range correction's effect was significant. The significant effect was shown by the increasing of energy barrier and the shortening of O-H interatomic distance in the transition state. Therefore, we suggest one should consider the long-range correction in modeling hydrogen bond dissociation in phenolic compounds, namely phenol and catechol.

Theoretical study on the adsorption of sulforaphane on B12N12-related nanocages based on density functional theory

“…The adsorption distance ( L ) (the distance between the O atom of SF drug and nanocages) between drug and BeB 11 N 12 nanocage is smaller than that between others, indicates that BeB 11 N 12 nanocage has greater adsorption capacity for SF drug, which also exactly confirms the result that the adsorption energy of SF@BeB 11 N 12 complex is the largest. However, in order to check on the B3LYP/6-311+G(d,p) method, the long-range functional, CAM-B3LYP/6-311+G(d,p), 48 was also considered to calculate the adsorption of drugs on nanocages. The results show that the adsorption energy values are slightly decreased, and the adsorption distances are also decreased at the CAM-B3LYP/6-311+G(d,p) level, suggesting that the long-range functional is more reliable for evaluating the stability of these studied complexes.…”

Theoretical Insights into the Carbon Linker Length Effects on the Radical Scavenging Activity of Curcumin

“…Developer M06-2X suggested it for thermochemical calculations [51]. We have used the XC for modeling an O─H and C-H bond dissociations previously [52,53]. Other researchers also used the XC to study other chemical reactions [54].…”