Visible-Light Photoredox Decarboxylation of Perfluoroarene Iodine(III) Trifluoroacetates for C–H Trifluoromethylation of (Hetero)arenes

A scalable and operationally simple decarboxylative trifluoromethylation of (hetero)­arenes with easily accessible C₆F₅I­(OCOCF₃)₂ under photoredox catalysis has been developed. This method is tolerant of various (hetero)­arenes and functional groups. Notably, C₆F₅I is recycled from the decarboxylation reaction and further used for the preparation of C₆F₅I­(OCOCF₃)₂. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the application of trifluoroacetic acid in trifluoromethylation reactions

Synthesis of 1,3,5-Tris(phenylamino) Benzene Derivatives and Experimental and Theoretical Investigations of Their Antioxidation Mechanism

1,3,5-Tris­(phenylamino) benzene and a series of its substitution derivatives were synthesized. The structure of the as-synthesized products was confirmed by nuclear magnetic resonance spectroscopy and high resolution mass spectra. Moreover, the antioxidation behavior of 1,3,5-tris­(phenylamino) benzene and its substitution derivatives as antioxidants in several ester oils was evaluated by a rotary oxygen bomb test and pressurized differential scanning calorimetry, while theoretical calculations were conducted to examine their antioxidation mechanism. It was found that 1,3,5-tris­(phenylamino) benzene exhibits better antioxidation ability at elevated temperature (150 and 210 °C) than commonly used commercial antioxidant diphenylamine. In the meantime, the substitution groups exhibit significant effects on the antioxidation behavior of 1,3,5-tris­(phenylamino) benzene and its derivatives. This is because the substituents result in changes in the molecular structure and electronic effect of the as-synthesized products, thereby causing s change in their antioxidation behavior

Prediction of Solubility Properties from Transfer Energies for Acidic Phosphorus-Containing Rare-Earth Extractants Using Implicit Solvation Model

<p>The differences of thermodynamics energies from the pure phase to a solution were used to predict the solubility properties of acidic phosphorus–containing rare-earth extractants. Four solvents, namely tributylphosphate, <i>n</i>-dodecane, toluene, and <i>n</i>-octanol were used. The thermodynamic cycle of the implicit solvation model and the structure model with short carbon chains were used. The relationship obtained by simulation of the solubility properties and extractant structures agreed qualitatively with reported experimental results. These results provide guidance for the design of new efficient extractants.</p

Theoretical Study of p<i>K</i>_a Values for Trivalent Rare-Earth Metal Cations in Aqueous Solution

Molecular acidity of trivalent rare-earth metal cations in aqueous solution is an important factor dedicated to the efficiency of their extraction and separation processes. In this work, the aqueous acidity of these metal ions has been quantitatively investigated using a few theoretical approaches. Our computational results expressed in terms of p<i>K</i>_a values agree well with the tetrad effect of trivalent rare-earth ions extensively reported in the extraction and separation of these elements. Strong linear relationships have been observed between the acidity and quantum electronic descriptors such as the molecular electrostatic potential on the acidic nucleus and the sum of the valence natural atomic orbitals energies of the dissociating proton. Making use of the predicted p<i>K</i>_a values, we have also predicted the major ionic forms of these species in the aqueous environment with different pH values, which can be employed to rationalize the behavior difference of different rare-earth metal cations during the extraction process. Our present results should provide needed insights not only for the qualitatively understanding about the extraction and separation between yttrium and lanthanide elements but also for the prediction of novel and more efficient rare-earth metal extractants in the future