Extended Hydrogen Bond Networks for Effective Proton-Coupled Electron Transfer (PCET) Reactions: The Unexpected Role of Thiophenol and Its Acidic Channel in Photocatalytic Hydroamidations.

Preorganization and aggregation in photoredox catalysis can significantly affect reactivities or selectivities but are often neglected in synthetic and mechanistic studies, since the averaging effect of flexible ensembles can effectively hide the key activation signatures. In addition, aggregation effects are often overlooked due to highly diluted samples used in many UV studies. One prominent example is Knowles's acceleration effect of thiophenol in proton-coupled electron transfer mediated hydroamidations, for which mainly radical properties were discussed.

Mixed Organometallic-Organic Hybrid Assemblies Based on the Diarsene Complex [Cp Mo (CO) (μ,η -As )], Ag Salts and N-Donor Organic Molecules.

The reaction of the organometallic diarsene complex [Cp Mo (CO) (η -As )] (1) with Ag[Al{OC(CF ) } ] (Ag[TEF]) yielded the Ag monomer [Ag(η -1) ][TEF] (2). This compound exhibits dynamic behavior in solution, which allows directed selective synthesis of unprecedented organometallic-organic hybrid assemblies upon its reaction with N-donor organic molecules by a stepwise pathway, which is supported by DFT calculations. Accordingly, the reaction of 2 with 2,2'-bipyrimidine (L1) yielded the dicationic molecular compound [{(η -1) Ag} (μ-L1)][TEF] (3) or the 1D polymer [{(η -1)Ag}(μ-L1)] [TEF] (4) depending on the ratio of the reactants.

Complexation behaviour of LiCl and LiPF- model studies in the solid-state and in solution using a bidentate picolyl-based ligand.

Structural knowledge on ubiquitous lithium salts in solution and in the crystalline state is of paramount importance for our understanding of many chemical reactions and of the electrolyte behaviour in lithium ion batteries. A bulky bidentate Si-based ligand (6) was used to create simplified model systems suitable for correlating structures of LiCl and LiPF complexes in the solid-state and in solution by combining various experimental, spectroscopic, and computational methods. Solution studies were performed using H DOSY, multinuclear variable temperature NMR spectroscopy, and quantum chemical calculations.

Selective Single C(sp)-F Bond Cleavage in Trifluoromethylarenes: Merging Visible-Light Catalysis with Lewis Acid Activation.

The conversion of easily available trifluoromethylarenes into aryldifluoromethyl compounds, which are valuable motifs in the pharmaceutical chemistry, is highly atom- and step-economical. However, the single C(sp)-F bond cleavage of ArCF is a great challenge because of the chemical inertness of the C(sp)-F bond and the difficult selectivity control of monodefluorination. We report here the first example of single C(sp)-F functionalization of trifluoromethylarenes via visible-light catalysis merged with Lewis acid activation.