A Highly Luminescent Tetramer from a Weakly Emitting Monomer: Acid‐ and Redox‐Controlled Multiple Complexation by Cucurbit[7]uril. Issue 23 (13th May 2014)

• Record Type: Journal Article
• Authors: Bergamini, Giacomo; Fermi, Andrea; Marchini, Marianna; Locritani, Mirko; Credi, Alberto; Venturi, Margherita; Negri, Fabrizia; Ceroni, Paola; Baroncini, Massimo
• Is Part Of: Chemistry. Volume 20:Issue 23(2014)
• Page Start: 7054
• Page End: 7060
• Publication Date: 2014-05-13
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201400375
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The tetrahedral, shape‐persistent molecule <bold>1</bold>⁴⁺, containing four pyridylpyridinium units connected through a central carbon atom, exhibits unexpected photophysical properties including a substantially redshifted absorption (2350 cm⁻¹) and a very strong fluorescence (<italic>Φ</italic>_em=40 %), compared with the monomer <bold>2</bold>⁺ (<italic>Φ</italic>_em=0.4 %). Density functional theory calculations on the structure and spectroscopic properties of <bold>1</bold>⁴⁺ and <bold>2</bold>⁺ show that exciton interactions, homoconjugation, and orbital nature account for the observed differences in their photophysical properties. The protonated tetramer binds four cucurbit[7]uril molecules and the host/guest interactions can be controlled by chemical (acid/base) as well as redox stimuli.</p> </abstract>