The emergence of visible light photoredox catalysis has enabled the productive use of lower energy radiation, leading to highly selective reaction platforms. Polypyridyl complexes of iridium and ruthenium have served as popular photocatalysts in recent years due to their long excited state lifetimes and useful redox windows, leading to the development of diverse photoredox-catalyzed transformations. The low abundances of Ir and Ru in the earth's crust and, hence, cost make these catalysts nonsustainable and have limited their application in industrial-scale manufacturing. Herein, we report a series of novel acridinium salts as alternatives to iridium photoredox catalysts and show their comparability to the ubiquitous [Ir(dF-CF3-ppy)2(dtbpy)](PF6).

Herein, we report half-peak potentials for over 180 organic substrates obtained via cyclic voltammetry. These values are of great use in assessing the thermodynamics of an electron-transfer process. In addition, we disclose a simple computational method to determine redox potentials of organic substrates.

The one-dimensional, particle-in-a-box model is an integral part of most undergraduate physical chemistry courses. Linear polyynes can be synthesized and are found to serve as real-world examples of the particle-in-a-box model. An improved set of experimental conditions for the laser synthesis of linear polyynes has been determined. Specifically, a Nd:YAG laser operating at 532 nm and 20 mJ/pulse for 5 min can produce sufficient polyynes to be detected with a UV–vis spectrophotometer. Students can use the experimental wavelength and the eigenvalue expression for the particle in a box to calculate the length of the box and compare it to the length of the molecule with good results. The lower laser energy used here is important because it enables a less costly laser to be used for the experiment, which will enable more instructors to incorporate the experiment into their curriculum.

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A novel 9-step diastereoselective route to the ABCD ring system of the natural product rubriflordilactone B is reported. Use of an a-substituted butenolide derived from maleic anhydride facilitated a 1,4-conjugate addition to provide a diene. The order in which a ring-closing metathesis and enolate oxidation were performed on this compound dictate the relative stereochemistry of the target. The final product exhibited anisotropic effects during room temperature NMR studies, requiring elevated temperature experiments to confirm its identity.