Electron redistribution is the cornerstone of our understanding of chemical reactivity. For the vast majority of organic reactions electrons are assumed to move in pairs providing explanatory mechanisms through the generation of intermediate structures. But for many transformations these discrete steps are idealized constructs, involving intermediates assumed but not empirically justified. This unitary perspective predicated on the curved arrow formalism has resulted in the scenario where for many organic transformations our supposed understanding far surpasses our growing knowledge. Reformulating organic mechanisms (...) to include single electron transfer as a component of, or an alternative to, the prevailing iconic descriptions can provide for a more empirically adequate mechanistic description. In addition using the language of SET presents an opportunity to unify mechanistic concepts under a common donor/acceptor framework. (shrink)

Heisenberg’s explanation of how two coupled oscillators exchange energy represented a dramatic success for his new matrix mechanics. As matrix mechanics transmuted into wave mechanics, resulting in what Heisenberg himself described as …an extraordinary broadening and enrichment of the formalism of the quantum theory , the term resonance also experienced a corresponding evolution. Heitler and London’s seminal application of wave mechanics to explain the quantum origins of the covalent bond, combined with Pauling’s characterization of the effect, introduced resonance into the (...) chemical lexicon. As the Valence Bond approach gave way to a soon-to-be dominant Molecular Orbital method, our understanding of the term resonance, as it might apply to our understanding the chemical bond, has also changed. (shrink)

Includes established theories and cutting-edge developments. Presents the work of an international group of experts. Presents the nature, origin, implications, and future course of major unresolved issues in the area.

Three experiments explored the effects of word problem cueing on debiasing versions of the bat-and-ball problem. In the experimental condition order, participants solved a simpler isomorphic version of the problem prior to solving a standard version that, critically, had the same item-and-dollar amounts. Conversely, in the control condition order, participants solved the standard version prior to solving the isomorph. Across the first 2 experiments, participants cued with the isomorph were more likely to correctly solve the standard version of the problem. (...) In the third experiment, this cueing effect was not replicated, but importantly cued participants were more likely to correctly solve the standard version of the problem with other item-and-dollar amounts, indicating near transfer. Far transfer was evident in faster response times to other problems in the Cognitive Reflection Test following practice. Along with providing converging evidence for the cueing account, these results are consistent with recent attentional debiasing findings. (shrink)