Two entries on bilateral hypergeometric series in Ramanujan's lost notebook

Two entries of bilateral sums in Ramanujan's lost notebook are confirmed by means of Dougall's bilateral series identities with one of them being corrected.

     

The rational homotopy Lie algebra of classifying spaces for formal two-stage spaces

We compute the center and nilpotency of the graded Lie algebra for a large class of formal spaces X. The latter calculation determines the rational homotopical nilpotency of the space of self-equivalences aut₁(X) for these X. Our results apply, in particular, when X is a complex or symplectic flag manifold.     

Sustainable routes to amines in recyclable water using ppm Pd catalysis

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Low-Energy Neutron Interaction with a Classical Electric Field

We explore the feasibility of performing experiments to detect the interaction of low-energy neutrons with a given classical electric field. Bound states could be identified by means of approximate Aharonov–Casher configurations. It is shown that neutron-bound states are found under extremely low-energy conditions and very strong electric fields.     

Synthesis of cyclic azobenzene analogues

Reaction of 2,2′-dinitrodibenzyl with lead metal powder in the presence of a basic triethylammonium formate buffer gave a cyclic azoxybenzene, 11,12-dihydrodibenzo[c,g][1,2]diazocine-5-oxide. The latter compound was converted into cyclic azobenzene and analogues (chloro-, bromo-, and cyano-) through subsequent transformations. Hydrolysis of the cyano cyclic azobenzene gave the corresponding carboxylic acid. This carboxylic acid was finally reacted with d-threoninol to give the corresponding amide, which readily undergoes photoisomerization upon illumination with light.     

Catalytic Asymmetric γ-Lactam Synthesis from Enolisable Anhydrides and Imines

An anion-binding approach to the problem of preparing enantioenriched γ-lactams from enolisable anhydrides and imines is reported. A simple bisurea catalyst promotes the cycloaddition between α-aryl succinic anhydrides and either PMP- or benzhydryl-protected aldimines to provide γ-lactams with two contiguous stereocentres (one quaternary) with complete diastereocontrol and high to excellent enantioselectivity for the first time. A DFT study has provided insight into the catalyst mode of action and the origins of the observed stereocontrol.     

Phenol-Catalyzed Discharge in the Aprotic Lithium-Oxygen Battery

Discharge in the lithium-O₂ battery is known to occur either by a solution mechanism, which enables high capacity and rates, or a surface mechanism, which passivates the electrode surface and limits performance. The development of strategies to promote solution-phase discharge in stable electrolyte solutions is a central challenge for development of the lithium-O₂ battery. Here we show that the introduction of the protic additive phenol to ethers can promote a solution-phase discharge mechanism. Phenol acts as a phase-transfer catalyst, dissolving the product Li₂O₂, avoiding electrode passivation and forming large particles of Li₂O₂ product—vital requirements for high performance. As a result, we demonstrate capacities of over 9 mAh cm⁻²_areal, which is a 35-fold increase in capacity compared to without phenol. We show that the critical requirement is the strength of the conjugate base such that an equilibrium exists between protonation of the base and protonation of Li₂O₂.