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• A series of Carbonic Anhydrase mimics were synthesized as CO2 hydration catalysts for enhancing CO2 absorption into carbon capture solvents. • Ancillary chloride ligands and a hydrophobic binding pocket are shown to be key features for activity of the catalysts. • DFT simulations suggest that [ZnII(PSAAMP)Cl2] and [ZnII(PSAMEA)Cl2] are catalyzing the CO2 hydration analogous to CA enzyme. • [ZnII(PSAAMP)Cl2] and [ZnII(PSAMEA)Cl2] are stable in harsh thermal and oxidative conditions with projected lifetimes >1500 h. • [ZnII(PSAAMP)Cl2] and [ZnII(PSAMEA)Cl2] exhibit 2–5 times greater enhancement in mass transfer than previous catalysts. Anthropogenic greenhouse gas emissions, such as CO 2 from fossil fuel combustion, are a global environmental, health, and economic concern. Aqueous amine-based CO 2 capture processes offer a technologically mature and relevant approach to CO 2 sequestration, although cost reduction strategies are still necessary for widespread deployment. Inspired by the metalloenzyme carbonic anhydrase (CA), we report the design, synthesis, and activity testing of zinc(II) complexes [ZnII(PSAAMP)Cl 2 ] (1) and [ZnII(PSAMEA)Cl 2 ] (2) as CO 2 hydration catalysts in aqueous amine solutions. The novel multifunctional ligand environment includes features in the primary and secondary coordination spheres that result in enhanced CO 2 mass transfer in industrially relevant carbon capture solvents and stability towards harsh industrial process conditions. Complexes that lack these key features do not show enhanced CO 2 absorption. Density functional theory (DFT) calculations that assess the catalytic pathway demonstrate how 1 and 2 catalyze CO 2 hydration analogous to CA. These catalysts increase mass transfer by 20–55% in lab scale experiments, offering the potential to reduce the cost of amine-based CO 2 capture processes without significantly altering industrial-scale system design, making rapid deployment of this critical bridge technology a viable strategy to reduce global greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Abstract: A series of 2,6-diarylethynyl-9,10-dialkoxyanthracenes have been synthesized, characterized, and evaluated for their morphological and electro-optical properties. Compounds with 2′-naphthyl and 2′-anthracyl peripheral substituents were found to have poor solubility, and were not explored in detail. However, compounds bearing 9′-anthracyl peripheral substituents exhibited better solubility, and a series of these compounds containing straight-chain and branched substituents were prepared and analyzed. These compounds were found to undergo two oxidations at +0.57V and +0.76V relative to a Fc/Fc+ reference. The compounds exhibited absorption with a λ onset of 510nm. Based on this, the average solution-phase HOMO–LUMO energies of these compounds were estimated to be −5.37eV and −2.94eV, respectively. The compounds exhibited fluorescent behavior, with an emission maximum at 505nm. Hexoxy and Isobutoxy substituents were optimal for large crystal formation, and crystallographic studies on these two compounds show a herringbone-type arrangement with 1-dimensional pi-stacking. [Copyright &y& Elsevier]

Photoreactive Ru(II) complexes capable of ejecting ligands have been used extensively for photocaging applications and for the creation of "photocisplatin" reagents. The incorporation of distortion into the structure of the coordination complex lowers the energy of dissociative excited states, increasing the yield of the photosubstitution reaction. While steric clash between ligands induced by adding substituents at the coordinating face of the ligand has been extensively utilized, a lesser known, more subtle approach is to distort the coordination sphere by altering the chelate ring size. Here a systematic study was performed to alter metal-ligand bond lengths, angles, and to cause intraligand distortion by introducing a "linker" atom or group between two pyridine rings. The synthesis, photochemistry, and photobiology of five Ru(II) complexes containing CH 2 , NH, O, and S-linked dipyridine ligands was investigated. All systems where stable in the dark, and three of the five were photochemically active in buffer. While a clear periodic trend was not observed, this study lays the foundation for the creation of photoactive systems utilizing an alternative type of distortion to facilitate photosubstitution reactions. Expansion of the bidentate bipyridine chelate ring results in photolabile Ru(II) complexes. [Display omitted] • Ru(II) complexes with expanded-chelate ligands are photolabile. • A systematic investigation of various linker atoms was undertaken. • Crystallographic studies reveal structural differences for ligands with different linkers. • All complexes were stable in the dark, and all but one ligand resulted in photolabile complexes. • The complexes induced DNA damage and some were moderately photocytotoxic to cancer cells. [ABSTRACT FROM AUTHOR]