Liquids often behave differently when confined inside a restricted space. Water, for example, can remain liquid at significantly lower temperatures (rather than freezing and becoming a solid) when it is confined. Confined liquids are being studied in many different areas of science including geology, biology, food, catalysis and drug preservation.
Researchers from the University of Manchester and Queen's University Belfast used neutron scattering at ISIS to obtain the structural properties of liquid benzene (the archetypical example of an aromatic compound) in confinement. Their results, published in Angewandte Chemie, show that the structure of liquid benzene is very different when it is confined. Confinement tends to change the local ordering between benzene molecules, which may change their reactivity, although more research is needed to confirm this.
Future experiments could explore how the behaviour depends on different parameters, by changing the size and shape of the confining pores, for example. The authors also hope to use complementary in situ techniques such as nuclear magnetic resonance (NMR) to extract more information.
Related publication: “Confinement Effects on the Benzene Orientational Structure" Angew. Chem. Int. Ed. 2018, 57, 4565-4570, DOI: 10.1002/anie.201713115
Authors: Marta Falkowska (The University of Manchester), Daniel T. Bowron (ISIS), Haresh Manyar (Queen's University Belfast), Tristan G. A. Youngs (ISIS), and Christopher Hardacre (The University of Manchester).