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This article examines the tools and techniques currently available that enable blind and visually impaired (BVI) individuals to visualize three-dimensional objects used in learning chemistry concepts. How BVI individuals engage with and visualize molecular structure is discussed and recent tactile (or haptic) and auditory methods for visualization of various chemistry concepts are summarized. Remaining challenges for chemistry education researchers are described with the aim of highlighting the potential value of educational research in further enabling BVI students to pursue careers in science, technology, engineering, and mathematics (STEM) fields.

Second order Jahn-Teller (SOJT) effects arise from interactions between filled and empty molecular orbitals of like symmetry. These interactions often lead to structural distortions whose extent is inversely proportional to the energy difference between the interacting orbitals. The main objectives of the work described here are (1) the calculation (using density functional theory methods) of the energies of the valence molecular orbitals in the species EH3 (E = N, P, As or Sb), HEEH (E = C, Si, Ge or Sn), and H2EEH2, (E = C, Si, Ge or Sn) and (2) the correlation of these energies with barriers for planarization or linearization. The calculations suggest an upper limit of about 12 eV energy separation of the interacting levels for SOJT effects to be significant, which is considerably larger than previously thought and implies that SOJT effects may be more common than currently realized.

The geometrical deviations from planar to folded or from linear to bent structures observed in multiply bonded heavy main group element analogues of ethylene and acetylene are treated from a second-order Jahn–Teller (SOJT) perspective. The structural distortions can be regarded as a consequence of a mixing of the filled highest occupied molecular orbital (HOMO) and an unoccupied orbital (LUMO+1). This mixing stabilizes the HOMO and destabilizes the unoccupied LUMO+1 orbital and produces nonbonding electron density, which causes the geometrical distortion through interelectronic repulsion. This occurs more readily in the heavier species because of their generally weaker bonds, which permit a closer approach and hence greater interaction of the molecular levels. Predicting which geometrical distortion enables the HOMO/LUMO+1 mixing requires knowledge of the symmetries of these frontier orbitals and the symmetry of the distortion. For the undistorted structures the product of the symmetries of the interactin...

Oxidopyrylium-alkene [5 + 2] cycloaddition conjugate addition cascade (C3) sequences are described. Intramolecular cycloadditions involving terminal alkenes, enals, and enones were investigated. Substrates with tethers of varying lengths delivered five- and six-membered carbocycles and heterocycles thus demonstrating the scope and limitation of the cycloaddition–conjugate addition cascade. Several experiments and theoretical calculations provide evidence for the proposed mechanistic pathway.

Density functional theory (DFT) calculations are used to probe the validity of mechanistic proposals for the conversion of isozizanoic acid to 12-norisoziza-5-ene, a reaction that occurs during steam distillation of vetiver oil. While this conversion corresponds overall to a simple decarboxylation, a multistep mechanism involving carbocation intermediates is supported by the computational results.

Oxidopyrylium-alkene [5 + 2] cycloaddition conjugate addition cascade (C

We strive to make chemistry more available and exciting for disabled scientists by developing accessible and safe methodologies to be employed by high school, undergraduate, and graduate students. We share philosophies and methods that were found to be effective in ensuring a safe laboratory environment. Namely, an accessible and safe chemistry laboratory requires assistance and extensive contributions from everyone involved. A discussion of technologies that make our computational chemistry laboratory accessible to blind and visually impaired (BVI) researchers follows. These recommendations are derived from our personal experiences with learning and teaching chemistry, with serving on a chemistry accessibility committee and with organizing and running chemistry camps for BVI students. In addition, we have begun work with sighted high school students who perform visual activities under blindfold. These experiences challenge the student under blindfold to learn how to function without all five senses while simultaneously training a sighted peer to safely and accurately assist with non-visual cues.

An ongoing challenge in modern catalysis is to identify and understand new modes of reactivity promoted by earth-abundant and inexpensive first-row transition metals. Herein, we report a mechanistic study of an unusual copper(I)-catalyzed 1,3-migration of 2-bromostyrenes that reincorporates the bromine activating group into the final product with concomitant borylation of the aryl halide bond. A combination of experimental and computational studies indicated this reaction does not involve any oxidation state changes at copper; rather, migration occurs through a series of formal sigmatropic shifts. Insight provided from these studies will be used to expand the utility of aryl copper species in synthesis and develop new ligands for enantioselective copper-catalyzed halogenation.

Curricula for three chemistry camp experiences for blind and visually impaired (BVI) individuals that incorporated single- and multiday activities and experiments accessible to BVI students are described. Feedback on the camps from students, mentors, and instructors indicates that these events allowed BVI students, who in many cases have been discouraged from doing science, to understand that chemistry can be made accessible and that they can think about chemistry on a level comparable to their sighted peers.

We describe accommodations that we have made to our applied computational–theoretical chemistry laboratory to provide access for blind and visually impaired students interested in independent investigation of structure–function relationships. Our approach utilizes tactile drawings, molecular model kits, existing software, Bash and Perl scripts written in-house, and three-dimensional printing in a process that allows a blind or visually impaired student to satisfy her or his curiosity about structure–function relationships with minimal assistance from sighted co-workers.

Quantum chemical calculations coupled to experiments were used to predict covalent hydration propensities of biologically relevant α-ketoamides. Experimentally determined hydration equilibrium constants for related ketones and aldehydes were compared to computationally determined values to develop a method for predicting hydration equilibrium constants. This method was used on six newly synthesized α-ketoamides to experimentally verify computational predictions. A correlation between calculation and experiment was observed and applied to models of several pertinent APIs. Our results indicate that the keto form is favored for practically all α-ketoamides in biological environs.

Contains fulltext : 153792.pdf (Publisher’s version ) (Closed access) Quantum chemical calculations on the isomerization of 24-methylenecycloartanol are described. An energetically viable mechanism, with a rate-determining protonation step, is proposed. This rearrangement may find applicability in tests for determining if an olive oil has been refined.