Unlocking Lewis acidity the redox non-innocence of a phenothiazine-substituted borane.

We describe a new approach to enhancing Lewis acidity, through the single electron oxidation of a borane with a pendant phenothiazine. This results in the formation of a persistent radical cation with increased electrophilicity. Computational and experimental studies indicate this radical cation significantly enhances the Lewis acidity and catalytic activity compared to its neutral analog.

Photocatalytic aerobic oxidation of benzylic alcohols and concomitant hydrogen peroxide production.

The photochemical oxidation of benzylic alcohols using -hydroxyphthalimide (NHPI) catalyst, with Rose Bengal as a singlet oxygen photosensitizer, and the production of hydrogen peroxide (HO) under metal-free conditions is presented. Computational and experimental investigations support O as the oxidant that converts NHPI to the active radical intermediate phthalimide--oxyl (PINO). This is a green alternative to current methods of HO production.

Orbital analysis of bonding in diarylhalonium salts and relevance to periodic trends in structure and reactivity.

Diarylhalonium compounds provide new opportunities as reagents and catalysts in the field of organic synthesis. The three center, four electron (3c-4e) bond is a center piece of their reactivity, but structural variation among the diarylhaloniums, and in comparison with other λ-iodanes, indicates that the model needs refinement for broader applicability. We use a combination of Density Functional Theory (DFT), Natural Bond Orbital (NBO) Theory, and X-ray structure data to correlate bonding and structure for a λ-iodane and a series of diarylchloronium, bromonium, and iodonium salts, and their isoelectronic diarylchalcogen counterparts.

Computational investigation into intramolecular hydrogen bonding controlling the isomer formation and p of octahedral nickel(II) proton reduction catalysts.

This work demonstrates the impact of intramolecular hydrogen bonding (H-bonding) on the calculated p of octahedral tris-(pyridinethiolato)nickel(II), [Ni(PyS)3]-, proton reduction catalysts. Density Functional Theory (DFT) calculations on a [Ni(PyS)3]- catalyst, and eleven derivatives, demonstrate geometric isomer formation in the protonation step of the catalytic cycle. Through Quantum Theory of Atoms in Molecules (QTAIM), we show that the p of each isomer is driven by intramolecular H-bonding of the proton on the pyridyl nitrogen to a sulfur on a neighboring ligand.

Functionalized resorcinarenes effectively disrupt the aggregation of αA66-80 crystallin peptide related to cataracts.

Cataracts, an eye lens clouding disease, are debilitating and while operable, remain without a cure. αA66-80 crystallin peptide abundant in cataracted eye lenses contributes to aggregation of αA-crystallin protein leading to cataracts. Inspired by the versatility of macrocycles and programmable guest selectivity through discrete functionalizations, we report on three water-soluble ionic resorcinarene receptors (, , and ) that disrupt the aggregation of αA66-80 crystallin peptide.