A noteworthy feature of bond dissociation/formation reactions

Abstract

ABSTRACT:The reaction force F(R c ) of a process is the negative derivative of the potential energy V(R c ) of the system with respect to the intrinsic reaction coordinate R c . For the dissociation of a bond, F(R c ) has a negative minimum at a point R c ϭ ␣, while for the formation of the same bond, F(R c ) has a maximum at R c ϭ ␣. These extrema divide the respective processes into two phases. For the dissociation, these correspond to an initial stretching of the XOY bond (structural effect) followed by separation into the fragments X and Y (electronic effects); for bond formation, the electronic phase is first (attractive interaction and gradual bond formation) and then the structural (relaxation to equilibrium separation). The noteworthy feature is that the key point R c ϭ ␣ always is such that V(␣), relative to the minimum of V(R c ), is about 27% of the dissociation energy.

Automating the IRC‐Analysis within Eyringpy

“…has been amply used to understand several chemical reactions such as intra/intermolecular single and double proton transfers [15][16][17][18][19][20][21], conformational changes [22][23], bond-dissociation and bond-formation [24][25][26][27][28], S N 2 substitution [29][30], solvent effects [31][32], and catalysts [33][34][35].…”

“…In 1999, the group of Toro‐Labbé [6] suggested the analysis of the reaction force (RFA) as a suitable tool for studying reaction mechanisms and identifying primitive processes in chemical reactions. The reaction force F ( ξ ), defined as the negative first derivative of the potential energy V ( ξ ) with respect to the reaction coordinate has been amply used to understand several chemical reactions such as intra/intermolecular single and double proton transfers [15–21], conformational changes [22–23], bond‐dissociation and bond‐formation [24–28], S N 2 substitution [29–30], solvent effects [31–32], and catalysts [33–35].…”

New insights into the gas-phase unimolecular fragmentations of [Cysteine–Ca]2+ complexes

“…Once the chemical potential is known it is possible to evaluate the reaction electronic flux, J(n), (REF) as [30,31]:…”

Structure, properties, and nature of the BrF‐HX complexes: An Ab initio study

“…They give an overview of halogen bonding [21]. Then they reported that analogous interactions are shown by atoms in Groups V and VI, and they have been compared quantitatively to hydrogen bonding [22][23][24][25]. Karpfen describes some calculations on BrF complexes with ammonia and amines [26].…”