Hydrogen‐bonded sheets in benzylmethylammonium hydrogen maleate

In the title compound, C₈H₁₂N⁺·C₄H₃O₄⁻, there is a short and almost linear but asymmetric O—H...O hydrogen bond in the anion. The ions are linked into C₂²(6) chains by two short and nearly linear N—H...O hydrogen bonds and the chains are further weakly linked into sheets by a single C—H...O hydrogen bond.     

Causal relations via linking in twistor space

We investigate the relationship between two different notions on linking, one homological and one holomorphic, in a twistorial context. The two notions turn out to be supprisingly closely related.     

Synchronization of ultraviolet-preionization in a Marx-driven TEA CO2 laser

In a TEA CO₂ laser a two-stage spark gap was used to control the predischarge, which produced the ultraviolet-preionization, and to generate a trigger pulse for the Marx bank, which excited the main discharge. The time-sequence of the predischarge and the trigger pulse could be reversed so that the main discharge could commence before the preionization process. This set-up has enabled temporal synchronization on the laser performance, or basically the time delay between the pre- and the main discharges, to be investigated from about − 150 ns to 600 ns.     

Catalysis with Pnictogen,Chalcogen, and Halogen Bonds

Halogen‐ and chalcogen‐based σ‐hole interactions have recently received increased interest in non‐covalent organocatalysis. However, the closely related pnictogen bonds have been neglected. In this study, we introduce conceptually simple, neutral, and monodentate pnictogen‐bonding catalysts. Solution and in silico binding studies, together with high catalytic activity in chloride abstraction reactions, yield compelling evidence for operational pnictogen bonds. The depth of the σ holes is easily varied with different substituents. Comparison with homologous halogen‐ and chalcogen‐bonding catalysts shows an increase in activity from main group VII to V and from row 3 to 5 in the periodic table. Pnictogen bonds from antimony thus emerged as by far the best among the elements covered, a finding that provides most intriguing perspectives for future applications in catalysis and beyond.     

C—H⋯π and π–π interactions in the supramolecular structure of 3‐methyl‐1,4‐diphenyl‐1H‐pyrazolo[3,4‐b]pyridine

The supramolecular structure of the title compound, C₁₉H₁₅N₃, is defined by π–π‐stacking and C—H?π interactions. There are no conventional hydrogen bonds in the structure.