Innovation and Team Spirit: The Magic of Science Competitions Seen through the Lens of the Compound Challenge.

For five years now, Merck KGaA, Darmstadt, Germany has hosted The Compound Challenge-a global retrosynthesis competition. When the event kicked off in 2018 on the occasion of the 350 anniversary of the company, no one could have predicted the path it would take-from a novel competition to a pivotal event within the synthetic chemistry community. But what makes the Compound Challenge tick and what drives its popularity? And, more importantly, what lessons can be taken from the Compound Challenge and applied to other challenges in scientific education and outreach? In this Viewpoint Article we will tell the story of the Compound Challenge, from its inception to its current status.

Near Quantitative Removal of Selenate and Sulfate Anions from Wastewaters by Cocrystallization with Chelating Hydrogen-Bonding Guanidinium Ligands.

Selenium (Se) has become an environmental contaminant of aquatic ecosystems as a result of human activities, particularly mining, fossil fuel combustion, and agricultural activities. By leveraging the high sulfate concentrations relative to Se oxyanions (i.e.

Direct air capture of CO- - topological analysis of the experimental electron density (QTAIM) of the highly insoluble carbonate salt of a 2,6-pyridine-bis(iminoguanidine), (PyBIGH)(CO)(HO).

Chemical bonding and all intermolecular interactions in the highly insoluble carbonate salt of a 2,6-pyridine-bis(iminoguanidine), (PyBIGH)(CO)(HO), recently employed in the direct air capture of CO via crystallization, have been analyzed within the framework of the quantum theory of atoms in molecules (QTAIM) based on the experimental electron density derived from X-ray diffraction data obtained at 20 K. Accurate hydrogen positions were included based on an analogous neutron diffraction study at 100 K. Topological features of the covalent bonds demonstrate the presence of multiple bonds of various orders within the PyBIGH cation.

Selective binding of (thio)sulfate and phosphate in water by quaternary ammonium functionalized oligo-ureas.

Recognition of (thio)sulfate and phosphate in aqueous solutions has been demonstrated by using oligo-urea-based receptors functionalized with quaternary ammonium groups. The ammonium groups allow for increased aqueous solubility while simultaneously providing positive coulombic interactions and stronger hydrogen bonding through an inductive effect. This simple and generally applicable modification provides an effective way to bolster the anion binding and water solubility of oligo-urea-based receptors.

Surprisingly selective sulfate extraction by a simple monofunctional di(imino)guanidinium micelle-forming anion receptor.

We report a novel di(imino)guanidinium anion extractant with unparalleled selectivity for sulfate in a liquid-liquid separation system. In addition to a 4.4 order-of-magnitude enhancement in affinity compared to a standard benchmark, our alkylated di(imino)guanidinium receptor is economically synthesized and features good compatibility with application-relevant aliphatic solvents.