Combined activation strain model and energy decomposition analysis methods: a new way to understand pericyclic reactions

Abstract

The recently introduced activation strain model (ASM) has allowed us to gain more insight into the intimacies of different fundamental processes in chemistry. In combination with the energy decomposition analysis (EDA) method, we have nowadays a very useful tool to quantitatively understand the physical factors that govern the activation barriers of reactions within organic and organometallic chemistry. In this Perspective article, we present selected illustrative examples of the application of this method to pericyclic reactions (Diels-Alder and double group transfer reactions) to show that this methodology nicely complements other more traditional, widely used theoretical methods.

Influence of the Transition‐Metal Fragment on the Reactivity of Metallaanthracenes

“…2.5-2.6 )i tb e-comesi ncreasingly more stabilizing up to the transition state region.T his behavior is shared not only for relatedD iels-Alder cycloaddition reactions [16] but also for differentt ypes of pericyclic reactions. [14] Despite that, the stabilization provided by the interaction term is overcome by the strong destabilizing effect of the deformation energy required to adopt the TS geometry (measured by the DE strain ), which, as ac onsequence, becomes the dominant factor controlling the barrierh eight of these [4+ +2]-cycloaddition reactions.…”

“…To gain aq uantitative understandingo ft he influence of the transition-metal moiety on the Diels-Alder reactivityn ot only of the fused-ring metallabenzene 1 but also of relatedc omplexes, we decided to apply the combinationo ft he so-called activation strain model (ASM) [12] of reactivity and the energy decomposition analysis( EDA) [13] methods. This ASM-EDAa pproach has successfully contributed to our current understanding of different types of fundamentalp rocesses in organic chemistry [14] as well as metal-promoted transformations. [15] The ASM-EDAm ethod has been particularly helpful to rationalize the Diels-Alder reactivity of both planar and bowl-shaped polycyclic aromatic hydrocarbons (PAHs).…”

The activation strain model and molecular orbital theory

“…In the following, we focus on understanding chemical reactivity, i.e., the reaction energy profile that accompanies the transformation of molecular species into new species. We will assume that the energy profile of a chemical reaction has been obtained to sufficient accuracy, and will discuss the application of the activation strain model of chemical reactivity, which has been developed to obtain more insight into the qualitative and quantitative features of the energy profile. This is done by splitting the relative energy of a molecular complex along the reaction coordinate into two separate terms, originating from the deformation of the reacting species and the interaction between them.…”

“…Within theoretical chemistry, this is done not by observation, but by a mathematical description of the physical system of interest. The constant improvement in the quality of mathematical descriptions, combined with the enormous advancement of computer technology in the profile of a chemical reaction has been obtained to sufficient accuracy, and will discuss the application of the activation strain model of chemical reactivity, [1][2][3][4][5] which has been developed to obtain more insight into the qualitative and quantitative features of the energy profile. This is done by splitting the relative energy of a molecular complex along the reaction coordinate into two separate terms, originating from the deformation of the reacting species and the interaction between them.…”

The Electronics of CH Activation by Energy Decomposition Analysis: From Transition Metals to Main-Group Metals

“…While there are several insightful studies that analyze distortion energies [27,[29][30][31], this chapter emphasizes interaction energies and its dissection into specific physical terms. This dissection can be done in several different styles.…”