A Host-Induced Intramolecular Charge-Transfer Complex and Light-Driven Radical Cation Formation of a Molecular Triad with Cucurbit[8]uril

• Published in: Journal of organic chemistry 2008-05, Vol.73 (10), p.3775-3783
• Main Authors: Zou, Dapeng, Andersson, Samir, Zhang, Rong, Sun, Shiguo, Åkermark, Björn, Sun, Licheng
• Format: Article
• Language: English
• Subjects: Chemistry; Condensed benzenic and aromatic compounds; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Organic chemistry; Preparations and properties
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo800110b

The host−guest chemistry of systems containing a molecular triad Ru(bpy)3-MV2+-naphthol complex (denoted as Ru2+-MV2+-Np, 1) and cucurbit[8]uril (CB[8]) is investigated by NMR, ESI-MS, UV−vis, and electrochemistry. The Ru2+-MV2+-Np guest and CB[8] host can form a stable 1:1 inclusion complex, in which the naphthalene residue is back-folded and inserted together with the viologen residue into the cavity of CB[8]. The selective binding of Ru2+-MV2+-Np guest with β-CD and CB[8] host is also investigated. We find that CB[8] binds the Ru2+-MV2+-Np guest stronger than β-CD. Upon light irradiation, a MV+• radical cation stabilized in the cavity of CB[8] accompanied by the naphthalene residue has been observed. This novel system may open a new way for design and synthesis of photoactive molecular devices.