Theoretical Insights into the Catalytic Effect of Transition-Metal Ions on the Aquathermal Degradation of Sulfur-Containing Heavy Oil: A DFT Study of Cyclohexyl Phenyl Sulfide Cleavage.

Steam injection is the most widely used technique for effectively reducing the viscosity of heavy oil in heavy oil production, in which in situ upgrading of heavy oil by aquathermolysis plays an important role. Earlier, transition-metal catalysts have been used for improving the efficiency of steam injection by catalytic aquathermolysis and achieving a higher degree of in situ oil upgrading. However, the unclear mechanism of aquathermolysis makes it difficult to choose efficient catalysts for different types of heavy oil.

Ferromagnetically Coupled Copper(II) Clusters Incorporated in Functionalized Boltorn H30 Hyperbranched Polymer Architecture: ESR, Magnetic Susceptibility Measurements, and Quantum-Chemical Calculations.

The unusual temperature behavior of the electron spin resonance (ESR) spectra and magnetic properties are experimentally observed in copper(II) complexes with a dendritic ligand based on the Boltorn H30 polymer (Perstorp Specialty Chemicals AB, Sweden) functionalized with fumaric acid residues in a molar ratio of 1:6. The ESR spectra at low temperatures show signs of transition to higher spin states at temperatures below 8-10 K, and the temperature dependences of the integral ESR signal intensities and magnetic susceptibility show the positive deviation from the Curie-Weiss law, thereby pointing to the presence of ferromagnetic exchange interactions in the system under study. The values of the exchange interaction parameters are calculated by quantum-chemical simulation of the possible structure of the copper(II) complex when assuming the formation of trinuclear coordination sites embedded in the hyperbranched polymer structure.

New insights into the solubility of graphene oxide in water and alcohols.

One of the main advantages of graphene oxide (GO) over its non-oxidized counterpart is its ability to form stable solutions in water and some organic solvents. At the same time, the nature of GO solutions is not completely understood; the existing data are scarce and controversial. Here, we demonstrate that the solubility of GO, and the stability of the as-formed solutions depend not just on the solute and solvent cohesion parameters, as commonly believed, but mostly on the chemical interactions at the GO/solvent interface.