Prussian blue analogues as aqueous Zn-ion batteries electrodes: Current challenges and future perspectives

The urgency of integrating renewable energy sources in the power grid has pushed the development of aqueous metal-ion batteries because of their low cost, nontoxicity, high safety, and environmentally friendliness. Among the variety of aqueous metal-ion batteries that are currently under development, aqueous Zn-ion batteries (A-ZIBs) have recently gained a great attention because of their high specific energy and high reversibility in aqueous solutions, together with the low cost and high abundancy of the zinc. In this article, the authors intend to present an overview of the Prussian blue analogue materials, which are among the most promising materials for positive electrodes in A-ZIBs because of their easier synthesis route, reversible ion-insertion, high safety, and low toxicity, highlighting their strength points and open challenges.     

An aqueous medium synthesis and tautomerism study of 3(5)-amino-1,2,4-triazoles

A catalyst-free highly efficient synthesis of 3(5)-amino-5(3)-(het)aryl-1,2,4-triazoles in aqueous medium was performed using conventional heating and microwave irradiation. The tautomerism in the products was investigated using NMR spectroscopy and X-ray crystallography. The effects of the substitution, temperature, solvents, and concentration on the tautomerism were studied. The triazoles were found to exist in 1H-forms, the 4H-form was not observed either in solid state or in solution. In general, 5-amino-1,2,4-triazoles were electronically preferred in the tautomeric equilibrium, but some exceptions from the established relationship were also identified.     

Organosilica Spheres Covalently Functionalized with Diphenylanthracene and Viologen Units

Organosilica spheres functionalized with two different photoactive units, diphenylanthracene, DPA@SPH, and viologen, VIO@SPH, covalently linked to the silica framework are prepared. These new materials have a uniform diameter, 300 nm for the DPA@SPH and 550 nm for the VIO@SPH, and exhibit the typical photochemical response of the organic moieties. It is observed that organic radical cations incorporated in the structure of the functionalized silica spheres are remarkably persistent. Due to their morphology and regular diameter DPA@SPH do not tend to aggregate and they form a highly regular, ordered and homogeneous multilayer film of high surface coverage which is employed as the active layer for the preparation of an electroluminescence cell.     

Lithium intercalation of phenyl-capped aniline dimers: a study by photoelectron spectroscopy and quantum chemical calculations

Structural and electronic properties of pristine and lithium-intercalated, phenyl-capped aniline dimers as a model for the lithium-polyaniline system have been studied by photoelectron spectroscopy and quantum chemical calculations. It was found that the electronic structure of reduced and oxidized forms of oligoanilines is only weakly affected by isomerism. Upon intercalation, charge transfer from the Li-atoms is remarkable and highly localized at N-atomic sites, where configurations are energetically favored in which both N atoms of the dimers are bound to Li atoms. Conversion of nitrogen sites is different for the two forms of aniline dimers and incomplete up to high intercalation levels, indicating a pronounced role of solid-state effects in the formation of such compounds.     

Studies toward soraphen A: an aldol-metathesis avenue to the macrocyclic framework

[reaction: see text] We describe a convergent approach to soraphen A, 1, that involves coupling of two fragments by an aldol condensation-olefin metathesis sequence. This route permits rapid access to congeners of 1.     

Total synthesis of topopyrones B and D

[reaction: see text] We describe a straightforward synthesis of topopyrones B and D, which are potent and selective inhibitors of topoisomerase I. The chemistry should be suitable for additional structure-activity relationship (SAR) work.     

The ultrametric correlation matrix for modelling hierarchical latent concepts

Advances in Data Analysis and Classification - Many relevant multidimensional phenomena are defined by nested latent concepts, which can be represented by a tree-structure supposing a hierarchical...     

Absolutely Convergent Extensions of Nonclosable Positive Linear Functionals

The existence of extensions of a positive linear functional ω defined on a dense *-subalgebra \mathfrakA₀{\mathfrak{A}_0} of a topological *-algebra \mathfrakA{\mathfrak{A}}, satisfying certain regularity conditions, is examined. The main interest is focused on the case where ω is nonclosable and sufficient conditions for the existence of an absolutely convergent extension of ω are given.