CT Complex Supramoecular Self-assembles Built With Cucurbit[8]uril

According to the literatures, as soon as MV2+ is reduced to MV+', a 2:1 inclusion radical dimer (MV+')2/CB[8](cucurbit[8]uril) will be formed immediately, leading to exclusion of the electron rich guest from the CB[8]cavity simultaneously. However, when MV2+moiety in complexes Ru(bpy)32+-(CH2)n-MV2+(n=4,7) were reduced to MV+·, a redox-induced radical Ru(bpy)32+-(CH2)n-MV+·(n=4,7) and its dimerization in CB[8]have been observed concomitantly in aqueous solution, which depends heavily on the length of the carbon chain linkage and the electron-rich guest.In recent years, near infrared (NIR) absorbing dyes are attracting more and more attention because of their potential applications in optoelectronic devices, photodynamic therapy (PDT). Unfortunately, this kind of synthesis is often time consuming and complicated. PTZ electron donor and MV2+ (N,N-dimethyl-4,4-bipyridinium) electron acceptor were mixed with CB[8]in aqueous solution here, an unusual ternary 1:1:1 host-guest complex exhibiting NIR absorption was formed due to intense CT interaction of the D-A dyad. Several methods such as Uv-vis, H-NMR spectra, ESI-MS, circular dichroism have been used to confirm the ternary inclusion complex. Due to the photosensitivity, the ternary inclusion complex exhibiting photocleavage ability on supercoiled plasmid DNA (pBR322), suggesting a potential application in photodynamic therapy.