A new family of tetra-anionic tetradentate amidate ligands, N1,N1'-(1,2-phenylene)bis(N2-methyloxalamide) (H4L1), and its derivatives containing electron-donating groups at the aromatic ring have been prepared and characterized, together with their corresponding anionic Cu(II) complexes, [(LY)Cu](2-). At pH 11.5, the latter undergoes a reversible metal-based III/II oxidation process at 0.56 V and a ligand-based pH-dependent electron-transfer process at 1.25 V, associated with a large electrocatalytic water oxidation wave (overpotential of 700 mV). Foot-of-the-wave analysis gives a catalytic rate constant of 3.6 s(-1) at pH 11.5 and 12 s(-1) at pH 12.5. As the electron-donating capacity at the aromatic ring increases, the overpotential is drastically reduced down to a record low of 170 mV. In addition, DFT calculations allow us to propose a complete catalytic cycle that uncovers an unprecedented pathway in which crucial O-O bond formation occurs in a two-step, one-electron process where the peroxo intermediate generated has no formal M-O bond but is strongly hydrogen bonded to the auxiliary ligand.

GoodVibes is an open-source Python toolkit for processing the results of quantum chemical calculations. Thermochemical data are not simply parsed, but evaluated by evaluation of translational, rotational, vibrational and electronic partition functions. Changes in concentration, pressure, and temperature can be applied, and deficiencies in the rigid rotor harmonic oscillator treatment can be corrected. Vibrational scaling factors can also be applied by automatic detection of the level of theory and basis set. Absolute and relative thermochemical values are output to text and graphical plots in seconds. GoodVibes provides a transparent and reproducible way to process raw computational data into publication-quality tables and figures without the use of spreadsheets.

Skin cancer incidence has been increasing in the last decades, but most of the commercial formulations used as sunscreens are designed to protect only against solar erythema. Many of the active components present in sunscreens show critical weaknesses, such as low stability and toxicity. Thus, the development of more efficient components is an urgent health necessity and an attractive industrial target. We have rationally designed core moieties with increased photoprotective capacities and a new energy dissipation mechanism. Using these scaffolds, we have synthesized a series of compounds with tunable properties suitable for their use in sunscreens, and enhanced properties in terms of stability, light energy dissipation, and toxicity. Moreover, some representative compounds were included in final sunscreen formulations and a relevant solar protection factor boost was measured.

Learning to stabilize palladium dimers Catalyst optimization is often difficult to do rationally. Once something works, it may be unclear which specific features underpin the performance. A case in point is the stabilization of palladium(I) dimers, which has relied on a very small class of phosphine ligands. Hueffel et al . used machine learning to search for patterns in this known class of ligands and thereby guide the discovery of variants that likewise stabilize the dimers. The authors were able to synthesize eight previously unreported dimers. —JSY

The systematic computational study of the mechanism for water oxidation in four different complexes confirms the existence of an alternative mechanism to those previously