Competitive Coordination of Chloride and Fluoride Anions Towards Trivalent Lanthanide Cations (La3+ and Nd3+) in Molten Salts

Molten salt electrolysis is a vital technique to produce high-purity lanthanide metals and alloys. However, the coordination environments of lanthanides in molten salts, which heavily affect the related redox potential and electrochemical properties, have not been well elucidated. Here, the competitive coordination of chloride and fluoride anions towards lanthanide cations (La³⁺ and Nd³⁺) is explored in molten LiCl-KCl-LiF-LnCl₃ salts using electrochemical, spectroscopic, and computational approaches. Electrochemical analyses show that significant negative shifts in the reduction potential of Ln³⁺ occur when F⁻ concentration increases, indicating that the F⁻ anions interact with Ln³⁺ via substituting the coordinated Cl⁻ anions, and confirm [LnCl_xF_y]^3−x−y (y_max=3) complexes are prevailing in molten salts. Spectroscopic and computational results on solution structures further reveal the competition between Cl⁻ and F⁻ anions, which leads to the formation of four distinct Ln(III) species: [LnCl₆]³⁻, [LnCl₅F]³⁻, [LnCl₄F₂]³⁻ and [LnCl₄F₃]⁴⁻. Among them, the seven-coordinated [LnCl₄F₃]⁴⁻ complex possesses a low-symmetry structure evidenced by the pattern change of Raman spectra. After comparing the polarizing power (Z/r) among different metal cations, it was concluded that Ln−F interaction is weaker than that between transition metal and F⁻ ions.     

Synthesis and Biological Activities of Diosgenin-Triazole Conjugates with a 1,3-Dipolar Cycloaddition Reaction

Chemistry of Natural Compounds - A novel series of diosgenin-triazole conjugates (10a–d, 11a–c, 12a–c, 13a–c) was designed and synthesized as antifungal agents by using a...     

SYNTHESIS,CHARACTERIZATION, CRYSTAL STRUCTURE,AND DFT STUDY OF N-(2-METHOXY-5- (4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL) PYRIDIN-3-YL)CYCLOPROPANESULFONAMIDE

Journal of Structural Chemistry - N-(2-methoxy-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-3-yl)cyclopropanesulfonamide is an organic intermediate with borate and sulfonamide groups,...     

Design study and heat transfer analysis of a neutron converter target for medical radioisotope production

A worldwide challenge in the near future will be to find a way of producing radioisotopes in sufficient quantity without relying on research reactors. The motivation for this innovative work on targets lies in the accelerator-based production of radioisotopes using a neutron converter target as in the transmutation by adiabatic resonance crossing concept. Thermal analysis of a multi-channel helium cooled device is performed with the computational fluid dynamics code CFX. Different boundary conditions are taken into account in the simulation process and many important parameters such as maximum allowable solid target temperature as well as uniform inlet velocity and outlet pressure changes in the channels are investigated. The results confirm that the cooling configuration works well; hence such a solid target could be operated safely and may be considered for a prototype target.     

A Mesoporous Сarbon Prepared by Сarbonizing Cu(II)–p-Phenylenediamine Polymer for the Adsorption of Methyl Orange from Water

Russian Journal of Physical Chemistry A - A new mesoporous carbon containing nitrogen and copper was prepared by carbonizing a polymer obtained by blending p-phenylenediamine, copper(II) sulfate,...     

Observability inequality for the Petrovsky equation

The aim of this paper is to study the exact controllability of the Petrovsky equation. Under some checkable geometric assumptions, we establish the observability inequality via the multiplier method for the Dirichlet control problem.     

Synthesis and rheological investigation of self‐healable deferoxamine grafted alginate hydrogel

Deferoxamine grafted alginate (SA‐DFA) was successfully synthesized via amidation of sodium alginate with deferoxamine mesylate as determined by H‐NMR and elemental analysis. SA‐DFA with different graft yield was obtained by adjusting the ratio of sodium alginate and deferoxamine mesylate. It was found that aqueous solution of SA‐DFA could form hydrogel spontaneously due to hydrogen bonding interactions, which also endowed the SA‐DFA hydrogel with self‐healing capability. The healing efficiency of SA‐DFA hydrogels ranged from 53.64 to 90.16%. In addition, surface morphologies of SA‐DFA hydrogels before/after self‐healing process were demonstrated by SEM images. We anticipated that such self‐healable alginate hydrogel would be applied in the field of wound healing. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 856–865     

Total synthesis of cannabisin F

A practical eight-step synthesis of lignanamide cannabisin F starting from vanillin is reported for the first time. This synthetic strategy applies the aldol reaction followed by the Wittig reaction to afford the key 8-O-4′-neolignan intermediate diacid. The diacid was condensed with N,O-protected tyramine giving, after deprotection, cannabisin F.     

A Photo-Responsive Organogel Based on Pyrene-Substituted Acylhydrazone Derivative

A new simple pyrene-substituted acylhydrazone derivative, 4-(3,4-dioctyloxy) phenyl-1-pyrene acylhydrazone (PAH-8), was designed and synthesized. The PAH-8 can form thermo-reversible organogel in DMSO, and shows gelation-induced enhanced fluorescence emission. Xerogel exhibits ribbon-like fibrous aggregates with widths of 0.5-1 μm. The PAH-8 organogel indicates photo-responsive behaviors due to the trans-cis isomerizations of -C=N- bond upon exposure to visible or UV light. Upon visible light irradiation, the partial trans-cis isomerization of the -C=N- bond causes the fiber morphology to disappear, resulting in gel-sol transition, whereas the PAH-8 organogel exhibits few photoisomerizations from trans to cis transition without breakage of the gel state upon UV light irradiation.