Conformational change due to intramolecular hydrophobic interaction leads to large blue-shifted emission from single molecular cage solutions. Issue 3 (11th December 2018)

• Record Type: Journal Article
• Authors: Li, Hui; Xie, Ting-Zheng; Liang, Zihao; Dahal, Dipendra; Shen, Yidan; Sun, Xinyu; Yang, Yuqing; Pang, Yi; Liu, Tianbo
• Is Part Of: Chemical communications. Volume 55:Issue 3(2019)
• Page Start: 330
• Page End: 333
• Publication Date: 2018-12-11
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/c8cc09038f
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : Intramolecular hydrophobic interaction in single metal–organic cage leads to the conformational change with a blue-shifted emission. Abstract : We demonstrate a unique negative solvatochromic emission (NSE) process from a conformational change of a coordination cage in response to solvent composition. The cationic cage contains two tetra-(4-pyridylphenyl)ethylene (TPPE) luminogens on two opposite faces, linked by Pt(PEt3 )2 and isophthalate. When the solvent changes from acetone/acetonitrile/methanol to water, the emission of single cages gradually shifts to short wavelength (NSE) with a drastic value of ∼60 nm. Small angle X-ray scattering (SAXS) measurements indicate a molecular conformational change during the process and intramolecular π–π stacking and hydrophobic interaction between the TPPE planes could be the driving forces. As a comparison, a cage with a longer inter-fluorophore distance does not have such strong intramolecular interactions and only shows regular positive solvatochromic emission (PSE) under the same conditions.