The need for further mechanistic understanding

The gap

Evidence profile

Sourced from the abstract and future work and stated research gap of the source papers, classified as general, drawn from work published between 2019 and 2026, spanning 3 journals. Those papers have been cited 70 times in total.

Supporting evidence — 4 representative gaps

• Mechanochemistry in Polymer Processing: Overview and Perspectives (2026) · DOAJ (DOAJ: Directory of Open Access Journals)

  Second, mechanochemical mechanisms under realistic processing conditions, where thermal, mechanical, oxidative, and chemical effects are strongly coupled, remain insufficiently understood, highlighting the need for integrated experimental, theoretical, and multiscale simulation approaches.

  generalabstract
  Keywords: second mechanochemical mechanisms realistic processing conditions thermal mechanical oxidative chemical effects strongly coupled remain insufficiently
• Kinetics of primary mechanochemical covalent-bond-forming reactions (2024) · RSC Mechanochemistry · cited 35× · doi

  Despite the advantages of mechanochemical reactions and the growing interest in using them in chemical fabrication, they have not yet been widely adopted by the synthetic community and incorporated into manufacturing processes for several reasons. These include unfamiliarity with the reactors used to carry out mechanochemical reactions, a lack of appreciation for mechanochemistry's substantial sustainability benets, and a poor understanding of how mechanochemical conditions alter reaction trajectories to dictate reaction selectivities – in other words, what distribution of products will form under mechanochemical reaction conditions. Here, we rst briey discuss how these reactions are performed and detail the sustainability benets of mechanochemistry. Understanding selectivity, however, is more challenging. The question of reaction selectivities – specically, why product ratios differ between mechanochemical conditions and solvothermal conditions – is not yet well-understood. Selectivity is a very important problem in mechanochemistry because grasping the molecular-scale origins of selectivity can lead directly to the understanding of how stresses affect reaction trajectories, and this knowledge could be used to develop predictive models that anticipate products and energy landscapes for reactions that have not yet been performed. As a direct consequence of solving the selectivity question, sustainable, mechanochemical reaction conditions could be designed to attain particular products. Understanding selectivities in chemical reactions is typically approached through the measurement of reaction kinetics to determine activation energies (Eas) and transition state geometries,18 however the measurement of kinetics in mechanochemical reactions has unique challenges that do not occur when studying reactions in solution. The rst challenge arises because the rates of mechanochemical reactions in mills or extruders are affected by coupled macroscopic and microscopic processes occurring in tandem (Fig. 2). The macroscopic processes – referred to here as the ‘secondary reactions’ – involve, for example, grinding powders into smaller pieces to expose reactive sites that had been buried inside solid particles. The microscopic process, or ‘primary reaction’, refers to the formation of covalent chemical bonds, like new C–C bonds, which are the same bond-forming processes that are typically followed when studying reaction kinetics in solution. These two terms have been used previously in the literature,19 and are interdependent in ball-mills and extruders. As such, understanding the contribution of force on molecular-scale processes requires disentangling microscopic/primary and macroscopic/ secondary processes, which may not always be possible. The second challenge is experimental, in that tracking the reactions under stress can be extremely difficult and requires specialized instrumentation.

  generalfuture workevidence 5/5
  Keywords: reactions reaction mechanochemical processes conditions chemical understanding selectivity used mechanochemistry selectivities products kinetics mills macroscopic
• Kinetics of primary mechanochemical covalent-bond-forming reactions (2024) · RSC Mechanochemistry · cited 35× · doi

  temperature uctuations and entropy,76 nuclear quantum effects,168 and non-adiabatic effects169 are not included. While MD and AIMD methods can address the effect of the tempera- ture and entropy, as well as be able to sample relevant reaction coordinates, they still suffer from increased computational costs and other limitations. A more comprehensive computa- tional investigating force-based reactivity must go beyond Born–Oppenheimer surfaces, but such a toolset has yet to be applied for the investigation of microscale molecular distortion on the rates and selectivities of CBFs. The complete multiscale computational toolset, however, should include the ‘secondary reaction’, such as mixing and grinding powders into smaller pieces. toolset Open questions in CBF mechanochemical reactions The tip-based studies of mechanically driven CBF reactions have led to an emerging consensus on how mechanochemical conditions – the application of uniaxial stress to a chemical reaction – drives primary CBF reactions towards products: uniaxial stress distorts and destabilizes bonds, thereby lowering the reaction energy. This paradigm suggests that the chemical reactions that are susceptible to mechanochemical conditions could be far greater than previously anticipated and provides an explanation of the anomalous mechanochemical selectivity that has been observed experimentally because the distorted tran- sition state is different than the transition state involved when using other modes of activation (e.g. solvothermal, electro- chemical, photochemical). With this new understanding of the mechanisms of mechanochemical understanding, several new questions about CBF mechanochemical reactions can be considered. These include: Are CBF mechanochemical reac- tions reversible? And can we create kinetic models that consider both primary and secondary reactions?

  generalfuture workevidence 5/5
  Keywords: mechanochemical reactions reaction toolset chemical entropy ects computational based include secondary questions conditions uniaxial stress
• Big Questions in Chemistry (2019) · Trends in Chemistry · doi

  The need for further mechanistic understanding of emerging classes of molecules, reactions, and materials. The lack of detailed relationships between synthesis conditions, molecular structure, and/or physiochemical properties.

  generalstated research gapevidence 5/5
  Keywords: need further mechanistic understanding emerging classes molecules reactions

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