Ab initio and quantum chemical topology studies on the isomerization of HONO to HNO2. Effect of the basis set in QCT
Berski, S; Latajka, Z; Gordon, AJ
| HERO ID | 834347 |
|---|---|
| In Press | No |
| Year | 2010 |
| Title | Ab initio and quantum chemical topology studies on the isomerization of HONO to HNO2. Effect of the basis set in QCT |
| Authors | Berski, S; Latajka, Z; Gordon, AJ |
| Journal | Journal of Computational Chemistry |
| Volume | 31 |
| Issue | 14 |
| Page Numbers | 2555-2567 |
| Abstract | The article focus on the isomerization of nitrous acid HONO to hydrogen nitryl HNO(2). Density functional (B3LYP) and MP2 methods, and a wide variety of basis sets, have been chosen to investigate the mechanism of this reaction. The results clearly show that there are two possible paths: 1) Uncatalysed isomerisation, trans-HONO --> HNO(2), involving 1,2-hydrogen shift and characterized by a large energetic barrier 49.7 divided by 58.9 kcal/mol, 2) Catalysed double hydrogen transfer process, trans-HONO + cis-HONO --> HNO(2) + cis-HONO, which displays a significantly lower energetic barrier in a range of 11.6 divided by 18.9 kcal/mol. Topological analysis of the Electron Localization Function (ELF) shows that the hydrogen transfer for both studied reactions takes place through the formation of a 'dressed' proton along the reaction path. Use of a wide variety of basis sets demonstrates a clear basis set dependence on the ELF topology of HNO(2). Less saturated basis sets yield two lone pair basins, V(1)(N), V(2)(N), whereas more saturated ones (for example aug-cc-pVTZ and aug-cc-pVQZ) do not indicate a lone pair on the nitrogen atom. Topological analysis of the Electron Localizability Indication (ELI-D) at the CASSCF (12,10) confirms these findings, showing the existence of the lone pair basins but with decreasing populations as the basis set becomes more saturated (0.35e for the cc-pVDZ basis set to 0.06e for the aug-cc-pVTZ). This confirms that the choice of basis set not only can influence the value of the electron population at the particular atom, but can also lead to different ELF topology. |
| Doi | 10.1002/jcc.21547 |
| Pmid | 20740554 |
| Wosid | WOS:000282309800003 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Source: Web of Science WOS:000282309800003 |
| Is Public | Yes |
| Language Text | English |
| Keyword | electron localization function; ELF; electron localizability indicator; ELI; topology; SAPT; hydrogen transfer; MP2; DFT; HNO2; HONO; nitrous acid; hydrogen nitryl; chemical bond |
| Is Qa | No |