A Phosphorescent Platinum(II) Bipyridyl Supramolecular Polymer Based on Quadruple Hydrogen Bonds

A platinum(II) bipyridyl complex bearing bis‐ureidopyrimidinone (Pt‐bisUPy) has been designed and its self‐assembling behavior has been thoroughly investigated by ¹H NMR, DOSY NMR, Ubbelohde viscometry analysis, UV/Vis, and emission spectroscopies. Pt‐bisUPy underwent concentration‐dependent ring‐chain polymerization in apolar solvents. Hydrogen‐bonding interactions play an important role during the formation of the supramolecular polymers. Hydrogen‐bonded supramolecular polymers were transformed to nanoparticles in water through the miniemulsion method. These nanoparticles showed strong π–π excimeric emission. Metal‐metal‐to‐ligand charge transfer (MMLCT) from Pt–Pt interactions was not significant in the emission spectrum. The phosphorescence of the nanoparticle persisted even under aerobic conditions. The triplet state of these phosphorescent nanomaterials were long‐lived and possessed moderate emission quantum yields. Furthermore, the low toxicity of these materials promises a place for them in in vitro and in vivo bioimaging.     

Fluorinated Musk Fragrances: The CF2 Group as a Conformational Bias Influencing the Odour of Civetone and (R)‐Muscone

The difluoromethylene (CF₂) group has a strong tendency to adopt corner over edge locations in aliphatic macrocycles. In this study, the CF₂ group has been introduced into musk relevant macrocyclic ketones. Nine civetone and five muscone analogues have been prepared by synthesis for structure and odour comparisons. X‐ray studies indeed show that the CF₂ groups influence ring structure and they give some insight into the preferred ring conformations, triggering a musk odour as determined in a professional perfumery environment. The historical conformational model of Bersuker and co‐workers for musk fragrance generally holds, and structures that become distorted from this consensus, by the particular placement of the CF₂ groups, lose their musk fragrance and become less pleasant.     

Application of the first collision source method to CSNS target station shielding calculation

Ray effects are an inherent problem of the discrete ordinates method. RAY3 D, a functional module of ARES, which is a discrete ordinates code system, employs a semi-analytic first collision source method to mitigate ray effects. This method decomposes the flux into uncollided and collided components, and then calculates them with an analytical method and discrete ordinates method respectively. In this article, RAY3 D is validated by the Kobayashi benchmarks and applied to the neutron beamline shielding problem of China Spallation Neutron Source(CSNS)target station. The numerical results of the Kobayashi benchmarks indicate that the solutions of DONTRAN3 D with RAY3 D agree well with the Monte Carlo solutions. The dose rate at the end of the neutron beamline is less than10.83 μSv/h in the CSNS target station neutron beamline shutter model. RAY3 D can effectively mitigate the ray effects and obtain relatively reasonable results.