Separation, analysis and recycling technologies are of high interest for our modern societies, where colloidal iron and aluminium (hydr)oxides have important applications. However, there are significant gaps in the fundamental understanding of how these phases form in real systems. Classical nucleation theory cannot account for many experimental observations, and there is a dichotomy between the chemistry of hydrolysing/condensating systems and the physical notion of supersaturation. Reviewing parts of the established and recent literature, we demonstrate that concepts of nonclassical nucleation pathways can overcome these issues. This broader, chemistry-based conceptual framework has a high potential for advancing current applications, and developing new strategies towards separation, analysis and recycling applications, which seem to be urgently required for the future. 相似文献
We report herein a detailed investigation into the reaction mechanism for a sequential oxy-Cope/ene reaction under anionic conditions. With DFT calculations and ab initio molecular dynamics simulations, the observed diastereoselectivity is shown to be the result of an isomerization of the enolate olefin, which would evidently not occur under neutral conditions. The potential energy surface was thoroughly mapped out for the reaction pathways and the proposed mechanism confirmed the different product distributions observed under neutral and anionic oxy-Cope conditions. In addition, other possible pathways are shown to be higher in energy and experimental evidence is given that supports the olefin-isomerization pathway. 相似文献
A new series of fluorine containing phenyl benzoates has been synthesized and the transition temperatures of these compounds have been determined. A series of 4-trifluoromethylphe 4nyl 4-n-alkybenzoates showed no liquid crystalline behaviour, but the 4-trifluoromethylphenyl 4-n-alkoxybenzoates series, with six carbons or more in alkoxy chain, was mesomorphic. The 4-cyanophenyl 4-perfluoroalkylbenzoates showed smectic liquid crystalline properties. 相似文献
Let the dominos fall : Synthesis of the complex DFGH ring system of the title compounds has been accomplished. The approach features simple treatment of the key intermediate with a Brønsted base to afford the tetracyclic cage‐shaped target in one pot through a four‐step domino transformation (see scheme; Mc= monochloromesylate, MOM=methoxymethyl).