Ab Initio and Quantum Chemical Topology studies on the isomerization of HONO to HNO2. Effect of the basis set in QCT

The article focus on the isomerization of nitrous acid HONO to hydrogen nitryl HNO2. 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 → HNO2, involving 1,2‐hydrogen shift and characterized by a large energetic barrier 49.7 ÷ 58.9 kcal/mol, 2) Catalysed double hydrogen transfer process, trans‐HONO + cis‐HONO → HNO2 + cis‐HONO, which displays a significantly lower energetic barrier in a range of 11.6 ÷ 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. 1 Use of a wide variety of basis sets demonstrates a clear basis set dependence on the ELF topology of HNO2. Less saturated basis sets yield two lone pair basins, V1(N), V2(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. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010

[1]  J. Pople,et al.  Self‐consistent molecular orbital methods. XX. A basis set for correlated wave functions , 1980 .

[2]  A. Savin,et al.  Classification of chemical bonds based on topological analysis of electron localization functions , 1994, Nature.

[3]  Y. Grin,et al.  Charge decomposition analysis of the electron localizability indicator: a bridge between the orbital and direct space representation of the chemical bond. , 2007, Chemistry.

[4]  P. Popelier.  Quantum Chemical Topology: Bonds and Potentials , 2005 .

[5]  David J. Giesen,et al.  The MIDI! basis set for quantum mechanical calculations of molecular geometries and partial charges , 1996 .

[6]  K. Pernal,et al.  Electron localizability indicator for correlated wavefunctions. II Antiparallel-spin pairs , 2004 .

[7]  T. H. Dunning.  Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen , 1989 .

[8]  B. Jursic.  Density functional theory exploring the HONO potential energy surface , 1999 .

[9]  Andreas Savin,et al.  Topological analysis of the electron localization function applied to delocalized bonds , 1996 .

[10]  Shin-ya Takane,et al.  Electronic structure and the hydrogen-shift isomerization of hydrogen nitryl HNO2 , 1994 .

[11]  Robert Moszynski,et al.  Perturbation Theory Approach to Intermolecular Potential Energy Surfaces of van der Waals Complexes , 1994 .

[12]  R. Bartlett,et al.  Thermodynamical stability of CH3ONO and CH3ONO-: A coupled-cluster and Hartree-Fock-density-functional-theory study , 1999 .

[13]  Jingsong Zhang,et al.  H + NO2 Channels in the Photodissociation of HONO at 193.3 nm† , 2001 .

[14]  S. F. Boys,et al.  The calculation of small molecular interactions by the differences of separate total energies. Some procedures with reduced errors , 1970 .

[15]  Mark S. Gordon,et al.  General atomic and molecular electronic structure system , 1993, J. Comput. Chem..

[16]  J. Pople,et al.  Self-consistent molecular orbital methods. 21. Small split-valence basis sets for first-row elements , 2002 .

[17]  M. Plesset,et al.  Note on an Approximation Treatment for Many-Electron Systems , 1934 .

[18]  K. Mierzwicki,et al.  The protocovalent NO bond: Quantum chemical topology (QCT of ELF and ELI-D) study on the bonding in the nitrous acid HONO and its relevancy to the experiment , 2008 .

[19]  Bernard Silvi,et al.  Topological analysis of electron density in depleted homopolar chemical bonds , 1999 .

[20]  Bernard Silvi,et al.  Computational Tools for the Electron Localization Function Topological Analysis , 1999, Comput. Chem..

[21]  Arvi Rauk,et al.  Orbital Interaction Theory of Organic Chemistry , 1994 .

[22]  Bernard Silvi,et al.  How Malonaldehyde Bonds Change during Proton Transfer , 1998 .

[23]  K Schulten,et al.  VMD: visual molecular dynamics. , 1996, Journal of molecular graphics.

[24]  J. Pople,et al.  Self—Consistent Molecular Orbital Methods. XII. Further Extensions of Gaussian—Type Basis Sets for Use in Molecular Orbital Studies of Organic Molecules , 1972 .

[25]  Parr,et al.  Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. , 1988, Physical review. B, Condensed matter.

[26]  Z. Latajka,et al.  QUANTUM CHEMICAL STUDY OF THE BIMOLECULAR COMPLEX OF HONO , 1999 .

[27]  Miroslav Kohout,et al.  A Measure of Electron Localizability , 2004 .

[28]  B. Silvi.  The synaptic order: a key concept to understand multicenter bonding , 2002 .

[29]  A. Becke.  Density-functional thermochemistry. III. The role of exact exchange , 1993 .

[30]  G. H. Purser.  Lewis Structures Are Models for Predicting Molecular Structure, Not Electronic Structure , 1999 .

[31]  A. Mebel,et al.  Rate Constant of the HONO + HONO → H2O + NO + NO2 Reaction from ab Initio MO and TST Calculations , 1998 .

[32]  Michael J. Frisch,et al.  Self‐consistent molecular orbital methods 25. Supplementary functions for Gaussian basis sets , 1984 .

[33]  Jiabo Li,et al.  Ab initio double-ζ (D95) valence bond calculations for the ground states of NO2, O3, and ClO2 , 2005 .

[34]  M. Lin,et al.  Gas Phase Reactions of HONO with NO2, O3, and HCl: Ab Initio and TST Study , 2000 .

[35]  E. Ratajczak,et al.  Spectroscopic and Theoretical Studies of the Complexes between Nitrous Acid and Ammonia , 1996 .

[36]  J. Simmie,et al.  Thermochemistry for enthalpies and reaction paths of nitrous acid isomers , 2007 .

[37]  M. Nguyen,et al.  Theoretical analysis of reactions related to the HNO2 energy surface: OH+NO and H+NO2 , 1998 .

[38]  A. Becke.  A New Mixing of Hartree-Fock and Local Density-Functional Theories , 1993 .

[39]  G. Scuseria,et al.  Gaussian 03, Revision E.01. , 2007 .

[40]  M. Lin,et al.  Gas-phase reactions of HONO with HNO and NH3: an ab initio MO/TST study , 2000 .

[41]  Mark S. Gordon,et al.  Self-consistent molecular-orbital methods. 22. Small split-valence basis sets for second-row elements , 1980 .