Event

Abstract 

Michaele Hardie, School of Chemistry, University of Leeds, UK

Cyclotriveratrylene (= CTV) is a pyramidal host molecule. We have developed a range of chiral tripodal CTV-analogues (L-type ligands) where the CTV scaffold has been functionalized with metal-binding ligand groups, and form discrete metallated cavitands, coordination cages, coordination polymers [1] and other networked assemblies.These include unusual topologically complicated assemblies including a unique chain-mail of Borromean rings.[2] A family of [Pd6L8] stella octangula cages can be synthesised, where small variations to the L ligand leads to different solution self-assembly and chiral self-sorting behaviour and stabilities. These differences can be exploited to dynamically control mixed ligand Pd6L8 speciation in solution.[3] M3L2 metallo-cages can be formed from a variety of metal and ligand combinations and frequently form as dimeric interlocked cage-catenane assemblies. Formation of M3L2 cages often requires a protecting chelating ligand on the metal which can be organometallic in nature. For example,  [Pd3(bis-NHC)3L2] cages (pictured) where bis-NHC is a chelating N-heterocyclic carbene ligand form crystalline materials that bind I2,[4]  and [{Ir(ppy)2}3L2]3+ metallocryptophanes, where ppy is 2-phenylpyridine are luminescent.[5] A series of [{Ir(C^N)2}3L2]3+ cages have been developed with embedded photo-switchable azo-groups. These show photo-induced trans-to-cis structure switching, the first examples of such switching of a structurally integral azo-unit within a metallo-cage (pictured).[6] We have also recently reported large cryptophanes through imine bond formation that implode into a previously unobserved fully collapsed structure.[7]

[1] review: Snelgrove, M. P.; Hardie, M. J. CrystEngComm 2021, 23, 4087

[2] Thorp-Greenwood, F. L.; Kulak, A. N.; Hardie, M. J. Nature Chem. 2015, 7, 526.

[3] Henkelis, J. J.; Fisher, J.; Warriner, S. L.; Hardie, M. J. Chem. Eur. J. 2014, 20, 4117.

[4] Henkelis, J. J.; Carruthers, C. J.; Chambers, S. E.; Clowes, R.; Cooper, A. I.; Fisher, J.; Hardie, M. J. J. Am. Chem. Soc. 2014, 136, 14393.

[5] Pritchard, V. E.; Rota Martir, D.; Oldknow, S.; Kai, S.; Hiraoka, S.; N. J. Cookson, N. J.; Zysman-Colman, E.; Hardie, M. J. Chem. Eur. J. 2017, 23, 6290.

[6] Oldknow, S.; Rota Martir, D.; Pritchard, V. E.; Blitz, M. A.; Fishwick, C. W. G.; Zysman-Colman, E.; Hardie, M. J. Chem. Sci. 2018, 9, 8150.

[7] Thorp-Greenwood, F. L. ; Howard, M. J.;  Kuhn, L. T.; Hardie, M. J. Chem. Eur. J. 2019, 25, 3536.

Host: Prof. Ivan Dmochowski