Exciting Warwick photochromic chemistry features in the latest edition of SCI Chemistry & Industry (C&I) Magazine.

Readers of C&I magazineLink opens in a new window may have recognised the work of Prof Mike Ward et al featured in the publication's Organic Chemistry Highlights in the July 2024 edition. Prof G. Richard Stephenson references a recent RSC Chemical Science article to spotlight 'switchable organic ligands for shape-changing coordination complexes'.

 
Prof Ward explains the research findings for everyday folk:

"Basically we have made some molecules that change shape when you shine light on them. That’s well known and is called ‘photochromism’. If you combine many of these molecules in bigger assemblies by stitching them together using metal ions, so the bigger assembly contains multiple copies of the smaller photochromic molecules, the change in shape of individual small molecules can lead to a large-scale change in the shape of the whole assembly.

Imagine making a lego model of something containing multiple small bricks, and each brick can change shape a bit when you shine light on it. The cumulative effect might be that the lego model fundamentally changes its structure (say, a house to a car) because all of the small bricks have individually undergone a smaller geometry change, and the large-scale model that results is fundamentally different. So we can trigger big structural changes in a multi-molecule assembly using light: and crucially if you shine light of a different colour on it, you can switch it back. So imagine converting your lego house and car back and forth by shining alternately red and blue light on it!"

For the scientific details, read Photoswitching of Co(ii)-based coordination cages containing azobenzene backbones.,Link opens in a new window Chem. Sci., 2024,15, 8488-8499,