A Host-Induced Intramolecular Charge-Transfer Complex and Light-Driven Radical Cation Formation of a Molecular Triad with Cucurbituril
journal contributionposted on 16.05.2008, 00:00 by Dapeng Zou, Samir Andersson, Rong Zhang, Shiguo Sun, Björn Åkermark, Licheng Sun
The host−guest chemistry of systems containing a molecular triad Ru(bpy)3-MV2+-naphthol complex (denoted as Ru2+-MV2+-Np, 1) and cucurbituril (CB) is investigated by NMR, ESI-MS, UV−vis, and electrochemistry. The Ru2+-MV2+-Np guest and CB 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. The selective binding of Ru2+-MV2+-Np guest with β-CD and CB host is also investigated. We find that CB binds the Ru2+-MV2+-Np guest stronger than β-CD. Upon light irradiation, a MV+• radical cation stabilized in the cavity of CB accompanied by the naphthalene residue has been observed. This novel system may open a new way for design and synthesis of photoactive molecular devices.