The integrated DL_POLY/DL_FIELD/DL_ANALYSER software platform for molecular dynamics simulations for exploration of the synthonic interactions in saturated benzoic acid/hexane solutions

Three separately developed software Molecular Dynamics packages at Daresbury Laboratory, namely DL_FIELD (DL_F), DL_POLY and DL_ANALYSER, have been integrated to form an efficient computational infrastructure to investigate the detailed solution chemistry of saturated benzoic acid in hexane solutions. These software capabilities are demonstrated, in combination with the Synthonic Engineering tools and density functional theory (DFT) calculations, to assess the extent that the solute-solute intermolecular synthonic interactions in solution mirrors the synthons in the crystal structure. The results show that the majority of the COOH groups are forming OH … O H-bonds, which are a combination of classic OH … O homo-dimers and three membered H-bonding clusters. The formation of pi-pi stacking interactions is observed, but in far fewer numbers than observed for the OH … O interactions. The DFT simulations of the IR spectra of the multiple benzoic acid aggregates extracted from the MD trajectories provides further in-depth analysis of previously published IR data, by matching simulated peaks to the experimental peaks, hence identifying the exact bonding modes that are responsible for such peaks. This study demonstrates the value of a multi-scale and multi-technique approach to exploring the molecular transition pathway from solution to crystal structure

Synthesis and growth of hematite nanodiscs through a facile hydrothermal approach

This study reports a facile hydrothermal method for the synthesis of monodispersed hematite (&alpha;-Fe2O3) nanodiscs under mild conditions. The method has features such as no use of surfactants, no toxic precursors, and no requirements of high-temperature decomposition of iron precursors in non-polar solvents. By this method, &alpha;-Fe2O3 nanodiscs were achieved with diameter of 50 &plusmn; 10 nm and thickness of ~6.5 nm by the hydrolysis of ferric chloride. The particle characteristics (e.g., shape, size, and distribution) and functional properties (e.g., magnetic and catalytic properties) were investigated by various advanced techniques, including TEM, AFM, XRD, BET, and SQUID. Such nanodiscs were proved to show unique magnetic properties, i.e., superparamagnetic property at a low temperature (e.g., 20 K) but ferromagnetic property at a room temperature (~300 K). They also exhibit low-temperature (&lt;623 K) catalytic activity in CO oxidation because of extremely clean surfaces due to non-involvement of surfactants, compared with those spheres and ellipsoids capped by PVP molecules.<br /