Synthesis and Crystal Structure of Blue Luminescent Cadmium(II) Coordination Networks with 4,4′-Bis(imidazol-1-ylmethyl)biphenyl from Different Solvent Systems

Two supramolecular complexes, [Cd(bimb)²Cl²] (1) and [Cd(bimb)(DMF)Cl²]·DMF (2) [bimb=4,4′-bis(imidazol-1-ylmethyl)biphenyl], were synthesized by reactions of CdCl²·2.5H²O with bimb ligand in ethanol and N,N′-dimethylformamide (DMF), respectively, and their structures were determined by X-ray crystallography. Complex 1 is an infinite 2D grid network bridged by bimb ligands, and the 2D sheets were further linked by C–H ?Cl hydrogen bonds to form a polycatenated 3D framework. Complex 2 has dicadmium(II) di-μ-chloride units which are connected by bimb bridging ligands to form an infinite non-interpenetrating 2D network. The results provide a nice example of the solvent system exerting a great effect on the construction of supramolecular frameworks.     

Epoxidation of Allylic Alcohols with Hydrogen Peroxide Catalyzed by [PMO12O40]3-[C5H5N+(CH2)15CH3]3

Applicatims a Mo- and W-based heteropoly acids (HPA) as a catalyst in the oxidation of olefins have extensively been investigated¹. However, a patent work is only attempted concerning the evoxidatim of olefins with H₂0₂ by HPA²⁾ since the oxirane ring is cleaved because of a strong acidity of HPA itself. Herein, an effective epoxidatim of some allylic alcohols with H₂0₂ by a new Mo-species (MPCP), which was prepared from 12-molybdatophosphoric acid (H₃PMo₁₂0₄₀) and cetylpyridinium chloride (C₅H₅N (CH₂), ₁₅CH₃- C1^-) under two-phase conditions using chloroform as an organic solvent, is described.     

Proto‐Urea‐RNA (Wöhler RNA) Containing Unusually Stable Urea Nucleosides

The RNA world hypothesis assumes that life on Earth began with nucleotides that formed information‐carrying RNA oligomers able to self‐replicate. Prebiotic reactions leading to the contemporary nucleosides are now known, but their execution often requires specific starting materials and lengthy reaction sequences. It was therefore proposed that the RNA world was likely proceeded by a proto‐RNA world constructed from molecules that were likely present on the early Earth in greater abundance. Herein, we show that the prebiotic starting molecules bis‐urea (biuret) and tris‐urea (triuret) are able to directly react with ribose. The urea‐ribosides are remarkably stable because they are held together by a network of intramolecular, bifurcated hydrogen bonds. This even allowed the synthesis of phosphoramidite building blocks and incorporation of the units into RNA. Investigations of the nucleotides’ base‐pairing potential showed that triuret:G RNA base pairs closely resemble U:G wobble base pairs. Based on the probable abundance of urea on the early Earth, we postulate that urea‐containing RNA bases are good candidates for a proto‐RNA world.     

Arylpyrrolyldiketone Boron Complexes Exhibiting Various Anion‐Binding Modes Based on Dynamic Conformation Changes

Arylpyrrolyldiketone boron complexes as anion‐responsive π‐electronic molecules were synthesized by Claisen condensations of acetylpyrrole and corresponding aryl esters. The synthesized π‐electronic molecules exhibited anion‐binding behavior with various binding modes including pyrrole‐inverted and non‐inverted [1+1]‐type anion complexes as well as [2+1]‐type complexes owing to the presence of only a single pyrrole ring. Furthermore, solid‐state ion‐pairing assemblies, comprising receptor–anion complexes and countercations, were constructed based on fairly planar [2+1]‐type complexes.     

Statistics of reaction progress variable and mixture fraction gradients of a pulverised coal jet flame using Direct Numerical Simulation data

The statistical behaviour of the variances, covariance and gradients of the reaction progress variable (c), and the mixture fraction (ξ) have been analysed in a pulverised coal jet flame using a three-dimensional carrier phase direct numerical simulation (DNS) dataset. It has been observed that the Favre-probability density functions (PDFs) of c and ξ can be parametrised by the standard β function. Furthermore, the log-normal distribution has been found to accurately represent |?c| and |?ξ|. It is also found that ?c and ?ξ remain aligned throughout the flame brush. Finally the joint PDF of |?c| and |?ξ| has been compared with the product of the PDF of |?c| and PDF of |?ξ| extracted from carrier phase DNS, and it has been found that |?c| and |?ξ| are not statistically independent in the case investigated.The bivariate log-normal distributions with and without correlation have also been considered, and the former is found to be in better agreement with the carrier phase DNS data.