Abstract Carbon capture and storage is an important strategy for stabilizing the increasing concentration of atmospheric CO 2 global temperature. A possible approach toward reversing this trend decreasing to remove directly from air (direct capture). Herein we report a simple aqueous guanidine sorbent that captures ambient binds it as crystalline carbonate salt by guanidinium hydrogen bonding. The resulting solid has very low solubility ( K sp =1.0(4)×10 −8 ), which facilitates its...

An effective approach to sulfate separation from aqueous solutions is based on the crystallization of extended [SO4(H2O)5(2-)]n sulfate-water clusters with a bis(guanidinium) ligand. The ligand was generated in situ by hydrazone condensation water, thereby bypassing need for elaborate syntheses, tedious purifications, and organic solvents. Crystallization represents an alternative now established strategies that involve encapsulation "naked" anion.

Selective crystallization of sulfate with a simple bis-guanidinium ligand, self-assembled in situ from terephthalaldehyde and aminoguanidinium chloride, was employed as an effective way to separate the highly hydrophilic anion aqueous solutions. The resulting bis-iminoguanidinium salt has exceptionally low solubility (Ksp =2.4×10-10 ), comparable that BaSO4 . Single-crystal X-ray diffraction analysis showed anions are sequestered [(SO4 )2 (H2 O)4 ]4- clusters within crystals....

We report a novel di(imino)guanidinium anion extractant with unparalleled selectivity for sulfate in liquid-liquid separation system. In addition to 4.4 order-of-magnitude enhancement affinity compared standard benchmark, our alkylated receptor is economically synthesized and features good compatibility application-relevant aliphatic solvents. Small-angle X-ray scattering results reveal the formation of reverse-micelles, which together significant organic-phase water content challenge...

Selenium (Se) has become an environmental contaminant of aquatic ecosystems as a result human activities, particularly mining, fossil fuel combustion, and agricultural activities. By leveraging the high sulfate concentrations relative to Se oxyanions (i.e., SeO n2-, n = 3, 4) present in some wastewaters, we have developed efficient approach Se-oxyanion removal by cocrystallization with bisiminoguanidinium (BIG) ligands that form crystalline sulfate/selenate solid solutions. The...

Abstract Carbon capture and storage is an important strategy for stabilizing the increasing concentration of atmospheric CO 2 global temperature. A possible approach toward reversing this trend decreasing to remove directly from air (direct capture). Herein we report a simple aqueous guanidine sorbent that captures ambient binds it as crystalline carbonate salt by guanidinium hydrogen bonding. The resulting solid has very low solubility ( K sp =1.0(4)×10 −8 ), which facilitates its...

Suzuki coupling of 10 and 11 resulted in 9, which was O-alkylated to provide 12. Treatment 12 with CsF DMF the formation completed core structure 13 a single step. Reductive amination synthesis (±)-cepharatine A, 4.

Abstract An effective approach to sulfate separation from aqueous solutions is based on the crystallization of extended [SO 4 (H 2 O) 5 2− ] n sulfate–water clusters with a bis(guanidinium) ligand. The ligand was generated in situ by hydrazone condensation water, thereby bypassing need for elaborate syntheses, tedious purifications, and organic solvents. Crystallization represents an alternative now established strategies that involve encapsulation “naked” anion.

It is shown that a simple guanidinium molecule binds sulfate selectively in methanol/water solution, and synthesized lipophilic analog permits the selective extraction of from aqueous sodium chloride into 1,2-dichloroethane. This receptor, N,N'-bis(2-pyridyl)guanidinium, features rigid pseudo-bicyclic conformation binding anions solid state. 10% water/90% MeOD-d4 solutions with stepwise log K1 K2 values 3.78 ± 0.12 2.10 0.23, respectively. Density functional theory calculations were...

Chemical bonding and all intermolecular interactions in the highly insoluble carbonate salt of a 2,6-pyridine-bis(iminoguanidine), (PyBIGH 2 )(CO 3 )(H O) 4 , recently employed direct air capture CO via crystallization, have been analyzed within framework quantum theory atoms molecules (QTAIM) based on experimental electron density derived from X-ray diffraction data obtained at 20 K. Accurate hydrogen positions were included an analogous neutron study 100 Topological features covalent bonds...

The first example of a pseudo-bicyclic guanidinium ligand is reported, and its complexes are evaluated by crystallographic computational approaches.

Functionalization of oligo-ureas with quaternary ammonium groups leads to water soluble receptors for selective binding adenosine phosphates in water.

α,α′,α″,α′″-meso-Tetrahexyltetramethyl-calix[4]pyrrole is easily obtained as a single diastereomer in one-pot reaction. It exhibits enhanced solubility organic solvents, including aliphatic relative to its parent meso-octamethylcalix[4]pyrrole (1). Somewhat surprisingly, the tetrahexyl derivative 2 complexes with tributylmethylammonium chloride chloroform more strongly than does 1 shown by NMR titrations. However, and exhibit comparable complexation strength extraction experiments,...

Abstract 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 occasion of 350 th anniversary company, no one could have predicted path it would take—from a novel competition to pivotal within synthetic chemistry community. But what makes Challenge tick and drives its popularity? And, more importantly, lessons can be taken from applied other challenges scientific education outreach? In...

Abstract 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 occasion of 350 th anniversary company, no one could have predicted path it would take—from a novel competition to pivotal within synthetic chemistry community. But what makes Challenge tick and drives its popularity? And, more importantly, lessons can be taken from applied other challenges scientific education outreach? In...

Die Synthese …︁…︁ von Glyoxalbis(amidiniumhydrazon)sulfat (in rot) wurde erstmals 1898 dem Chemiker Johannes Thiele beschrieben. Jetzt analysieren R. Custelcean et al. in ihrer Zuschrift auf S. 10671 ff. die Kristallstruktur dieses Salzes, sich durch ausgedehnte wasserstoffverbrückte Sulfat-Wasser-Cluster auszeichnet (rechts). kompetitive Kristallisation dieser Cluster kann zur Sulfat-Abscheidung aus wässrigen Lösungen eingesetzt werden.

In dieser Zuschrift wurde die Kristallstruktur des Sulfatsalzes von Glyoxalbis(amidiniumhydrazon) (GBAH) beschrieben, das Thiele und Dralle im Jahr 1898 erstmals synthetisiert wurde.1 Diese Struktur zeigt ausgedehnte [SO4(H2O)52–]n-Cluster. Ein wichtiger Aspekt der Studie bestand darin, zu zeigen, dass konkurrierende Kristallisation GBAH-Sulfat aus wässrigen Lösungen als Grundlage für eine selektive Sulfatabtrennung dienen kann. Die Effektivität Sulfatabtrennnungsmethode ergibt sich...

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand synthesized as the chloride salt (BBIG-Cl) in situ imine condensation of terephthalaldehyde aminoguanidinium water, followed (BBIG-SO4). Alternatively, BBIG-Cl ex larger scale ethanol. ability BBIG demonstrated quantitative seawater. can be recycled neutralization BBIG-SO4 NaOH neutral...

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand synthesized as the chloride salt (BBIG-Cl) in situ imine condensation of terephthalaldehyde aminoguanidinium water, followed (BBIG-SO4). Alternatively, BBIG-Cl ex larger scale ethanol. ability BBIG demonstrated quantitative seawater. can be recycled neutralization BBIG-SO4 NaOH neutral...