Vernier-Templated Synthesis, Crystal Structure, and Supramolecular Chemistry of a 12-Porphyrin Nanoring

Kondratuk, Dmitry V.; Sprafke, Johannes K.; O'Sullivan, Melanie C.; Perdig�o, Luis M.A.; Saywell, Alexander; Malfois, Marc; O'Shea, James N.; Beton, Peter H.; Thompson, Amber L.; Anderson, Harry L.

Abstract

Vernier templating exploits a mismatch between the number of binding sites in a template and a reactant to direct the formation of a product that is large enough to bind several template units. Here, we present a detailed study of the Vernier-templated synthesis of a 12-porphyrin nanoring. NMR and small-angle X-ray scattering (SAXS) analyses show that Vernier complexes are formed as intermediates in the cyclo-oligomerization reaction. UV/Vis/NIR titrations show that the three-component assembly of the 12-porphyrin nanoring figure-of-eight template complex displays high allosteric cooperativity and chelate cooperativity. This nanoring–template 1:2 complex is among the largest synthetic molecules to have been characterized by single-crystal analysis. It crystallizes as a racemate, with an angle of 27° between the planes of the two template units. The crystal structure reveals many unexpected intramolecular C[BOND]H⋅⋅⋅N contacts involving the tert-butyl side chains. Scanning tunneling microscopy (STM) experiments show that molecules of the 12-porphyrin template complex can remain intact on the gold surface, although the majority of the material unfolds into the free nanoring during electrospray deposition.

Citation

Kondratuk, D. V., Sprafke, J. K., O'Sullivan, M. C., Perdigão, L. M., Saywell, A., Malfois, M., …Anderson, H. L. (2014). Vernier-Templated Synthesis, Crystal Structure, and Supramolecular Chemistry of a 12-Porphyrin Nanoring. Chemistry - A European Journal, 20(40), 12826-12834. https://doi.org/10.1002/chem.201403714

• Journal Article Type: Article
• Acceptance Date: May 28, 2014
• Online Publication Date: Aug 25, 2014
• Publication Date: Sep 26, 2014
• Deposit Date: Jul 14, 2016
• Publicly Available Date: Jul 14, 2016
• Journal: Chemistry - A European Journal
• Print ISSN: 0947-6539
• Electronic ISSN: 1521-3765
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Issue: 40
• Pages: 12826-12834
• DOI: https://doi.org/10.1002/chem.201403714
• Keywords: Conjugation, Macrocycles, Porphyrinoids, Supramolecular chemistry, Template synthesis
• Public URL: https://nottingham-repository.worktribe.com/output/733825
• Publisher URL: http://dx.doi.org/10.1002/chem.201403714
• Contract Date: Jul 14, 2016