One‐Step Solvothermal Synthesis of Single‐Crystalline TiOF2 Nanotubes with High Lithium‐Ion Battery Performance

Single‐crystalline TiOF₂ nanotubes were prepared by a one‐step solvothermal method. The nanotubes are rectangular in shape with a length of 2–3 μm, width of 200–300 nm, and wall thickness of 40–60 nm. The formation of TiOF₂ nanotubes is directly driven by the interaction between TiF₄ and oleic acid in octadecane to form the 1D nanorods, and this is followed by a mass diffusion process to form the hollow structures. The synthesis approach can be extended to grow TiOF₂ nanoparticles and nanorods. Compared with TiO₂, which is the more commonly considered anode material in lithium‐ion batteries, TiOF₂ has the advantages of a lower Li‐intercalation voltage (e.g., to help increase the total voltage of the battery cell) and higher specific capacities. The TiOF₂ nanotubes showed good Li‐storage properties with high specific capacities, stable cyclabilities, and good rate capabilities.     

Two New Low Dimensional Lead(Ⅱ) Diiodide Complexes by Introducing Carbonyls on 1,10-Phenanthroline: a Combined Experimental and Theoretical Study

Two new low dimensional lead(Ⅱ) diiodide complexes with 1,10-phenanthroline-5,6-dione(Phendione), PbI2(Phendione)2(1) and PbI2(Phendione)(DMSO)2(2), have been synthesized by solution processes and structurally determined by X-ray diffraction method. Both compounds are mononuclear with the lead centers being in highly distorted octahedral environments. Hydrogen bonds and π-π stacking interactions contribute to the structural extension and stabilization. Theoretical calculations based on the DFT/B3 LYP level indicate that the introduction of electronic donating groups on the phenanthroline ring can improve the electron density of nitrogen atoms, and they can replace part of the bridged iodine atoms to lower the structural dimensions. Experimental band gaps of about 2.07 and 1.97 eV indicate their semiconductor nature.     

One‐Pot Synthesis of 2‐(1‐Alkyl/aralkyl‐1H‐benzimidazole‐2‐yl)‐quinoxaline Derivatives using Molecular Iodine

The title compound (5) has been prepared in one pot by refluxing 1‐(1‐alkyl/aralkyl‐1H‐benzimidazole‐2‐yl)‐ethanone (1) with substituted o‐phenylenediamine (2) in ethanol in the presence of iodine. Alternatively, 5 could also be prepared by treating 2‐bromo‐1‐(1‐ alkyl/aralkyl‐1H‐benzimidazole‐2‐yl)‐ethanone (3A) with 2 in refluxing ethanol. The formation of 5 from 1 and 2 probably occurs through the intermediacy of 3B (i.e., 3, X=I) and 4.     

Synthesis and physical properties of tolane liquid crystals containing 2,3-difluorophenylene and terminated by a tetrahydropyran moiety

Four series of tolane liquid crystals containing 2,3-difluorophenylene and terminated by a tetrahydropyran (THP) moiety have been synthesised via multistep reactions based on 4-alkylcyclohexanecarboxylic acids and 4-bromo-2,3-difluorophenol. Their properties were measured by differential scanning calorimetry, polarising optical microscopy, Abbe refractometer and an electrical constants instrument. The results show that the THP-based liquid crystals nT reveal a relatively high value of the birefringence, negative dielectric anisotropy, good solubility and a broad nematic mesophase. The effects of the terminal alkyl chain, the lateral fluoro substituents and the THP terminal group on the mesomorphic and physical properties are discussed. Meanwhile, density functional theory calculations of molecular conformation and polarisability were conducted to correlate the experimental findings.