Visible Light-Driven Artificial Molecular Switch Actuated by Radical-Radical and Donor-Acceptor Interactions

Junling Sun, Yilei Wu, Zhichang Liu, Dennis Cao, Yuping Wang, Chuyang Cheng, Dongyang Chen, Michael R. Wasielewski*, J. Fraser Stoddart

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


We describe a visible light-driven switchable [2]catenane, composed of a Ru(bpy)32+ tethered cyclobis(paraquat-p-phenylene) (CBPQT4+) ring that is interlocked mechanically with a macrocyclic polyether consisting of electron-rich 1,5-dioxynaphthalene (DNP) and electron-deficient 4,4′-bipyridinium (BIPY2+) units. In the oxidized state, the CBPQT4+ ring encircles the DNP recognition site as a consequence of favorable donor-acceptor interactions. In the presence of an excess of triethanolamine (TEOA), visible light irradiation reduces the BIPY2+ units to BIPY(•+) radical cations under the influence of the photosensitizer Ru(bpy)32+, resulting in the movement of the CBPQT2(•+) ring from the DNP to the BIPY(•+) recognition site as a consequence of the formation of the more energetically favorable trisradical complex, BIPY(•+) CBPQT2(•+). Upon introducing O2 in the dark, the BIPY(•+) radical cations are oxidized back to BIPY2+ dications, leading to the reinstatement of the CBPQT4+ ring encircled around the DNP recognition site. Employing this strategy of redox control, we have demonstrated a prototypical molecular switch that can be manipulated photochemically and chemically by sequential reduction and oxidation.

Original languageEnglish (US)
Pages (from-to)6317-6325
Number of pages9
JournalJournal of Physical Chemistry A
Issue number24
StatePublished - Jun 18 2015

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry


Dive into the research topics of 'Visible Light-Driven Artificial Molecular Switch Actuated by Radical-Radical and Donor-Acceptor Interactions'. Together they form a unique fingerprint.

Cite this