Abstract
The reaction pathway for the rupture of the carbon–carbon double bond of C2F4 has been calculated with ab initio methods at the CASSCF(8,8)+NEVPT2/aug-cc-pVTZ and CCSD(T)/aug-cc-pVTZ levels and with density functional theory using M06-L and M06-2X functionals in conjunction with aug-cc-pVTZ basis sets. The calculations suggest that the bond dissociation pathway proceeds by a nonlinear reaction course without an activation barrier yielding the CF2 fragments in the (1A1) ground state. A bonding analysis indicates that there is a continuous change in the electronic structure of the CF2 fragments during the elongation of the C–C distance from a (3B1) excited state at the equilibrium geometry of C2F4 to the (1A1) ground state. EDA-NOCV calculations suggest that the carbon–carbon interactions in C2F4 at equilibrium distance and longer C–C values up to ≈1.60 Å are best described in terms of electron-sharing bonding between the CF2 fragments in the (3B1) excited state. At longer distances, the situation changes toward dative bonding between CF2 fragments in the (1A1) ground state.
Original language | English |
---|---|
Pages (from-to) | 9083-9089 |
Number of pages | 7 |
Journal | Chemistry - A European Journal |
Volume | 24 |
Issue number | 36 |
DOIs | |
State | Published - 26 Jun 2018 |
Keywords
- bonding analysis
- dative bonding
- electron-sharing bonding
- quantum chemical calculations
- reaction mechanism