Interference Energy in C–H and C–C Bonds of Saturated Hydrocarbons: Dependence on the Type of Chain and Relationship to Bond Dissociation Energy

Abstract

Interference energy for C-H and C-C bonds of a set of saturated hydrocarbons is calculated by the generalized product function energy partitioning (GPF-EP) method in order to investigate its sensitivity to the type of chain and also its contribution to the bond dissociation energy. All GPF groups corresponding to chemical bonds are calculated by use of GVB-PP wave functions to ensure the correct description of bond dissociation. The results show that the interference energies are practically the same for all the C-H bonds, presenting only small variations (0.5 kcal.mol(-1)) due to the structural changes in going from linear to branched and cyclic chains. A similar trend is verified for the C-C bonds, the sole exception being the cyclopropane molecule, for which only the C-C bond exhibits a more significant variation. On the other hand, although the interference energy is quantitatively the most important contribution to the bond dissociation energy (DE), one cannot predict DE only from the bond interference energy. Differences in the dissociation energies of C-C and C-H bonds due to structural changes in the saturated hydrocarbons can be mainly attributed to quasi-classical effects.

The Nature of the Chemical Bond from a Quantum Mechanical Interference Perspective

“…This is illustrated in Figures a‐b, for the LiH (μ= −5.882 D) and BH (μ=1.270 D) molecules. Moreover, this interference stabilization comes from the kinetic contribution, in agreement with previous studies . This is a strong evidence that, despite the difference of electronegativity between the atoms involved, all of the molecules described herein form typical covalent bonds.…”

“… Energy profiles for dissociation of the C−H bond in methane and the C−C bond in ethane (Adapted from ref …”

“…In order to verify the generality of the IEA results we examined different types of systems exhibiting distinct bonding patterns. Diatomic and polyatomic molecules, with single double and triple bonds, with different degrees of polarity, linear or branched, cyclic or not, conjugated and aromatics, have been considered. In all cases the conclusion was exactly the same : for each bond of a diatomic or polyatomic molecule the results of the energy partitioning into interference and quasi‐classical contributions showed that the main contribution to the depth of the potential wells comes from the interference term, showing that EAI analysis provides a unified view of the chemical bond.…”

The consequences of neglecting permutation symmetry in the description of many‐electrons systems

“…To verify the generality of the IEA results, we examined different types of systems exhibiting distinct bonding patterns. Diatomic and polyatomic molecules, with single double and triple bonds, with different degrees of polarity, linear or branched, cyclic or not, conjugated and aromatics, as well as one‐electron bonds have been considered . In all cases, the conclusion was exactly the same: for each bond of a diatomic or polyatomic molecule, the results of the energy partitioning into interference and quasi‐classical contributions showed that the main contribution to the depth of the potential wells comes from the interference term and that its kinetic component is the responsible for the stability of the bond.…”

Curly arrows, electron flow, and reaction mechanisms from the perspective of the bonding evolution theory

“…Very recently, as mentioned earlier, Knizia et al have presented the intrinsic bond orbitals that can be associated with a non-empirical form of localized molecular orbitals to obtain the electron flow for reaction mechanisms. 75,[123][124][125] On the other hand, topological analysis is a useful tool to characterize intra-and intermolecular interactions, and different types of bonding analysis methods are based on the topology of scalar fields, 126 while different applications have already been published in the literature. The name 'quantum chemical topology' 136,137 has been introduced to embrace all topological investigations of three-dimensional scalar fields 46,[138][139][140][141][142][143][144] in order to rationalize the chemical bond and gain further understanding of the chemical reactivity.…”