Unusual partner radical trimer formation in a host complex of cucurbit[8]uril, ruthenium(ii) tris-bipyridine linked phenol and methyl viologen

Abstract

A stable 1:1:1 inclusion complex of Ru(bpy)(3)-phenol (1), MV(2+) and cucurbit[8]uril (CB[8]) is formed in aqueous solution. In the presence of triethanolamine (TEOA), a light-induced formation of unusual partner radical trimer 1-(MV(+*))(2)-CB[8] has been observed for the first time.

Study of the Counter Anions in the Host‐Guest Chemistry of Cucurbit[8]uril and 1‐Ethyl‐1′‐benzyl‐4,4′‐bipyridinium

“…BEV-(PF 6 ) 2 was synthesized according to the literature [24]. And the anions were exchanged to the corresponding halide anions by ion exchange experiments.…”

Redox-induced Ru(bpy)32+-methylviologen radical formation and its dimerization in cucurbit[8]uril

“…In recent years, the host-guest chemistry of the cucurbituril family has been making big progress since Kim, 1 Day 2 and their co-workers reported the preparation of different cucurbit [n]uril (CB[n], n = 5, 7, 8, 9, 10) and their homologues. Among them, the inclusion chemistry of CB [8] seems much more interesting, owing to the fact that it can accommodate two identical 3 or different 4 aromatic guests in its cavity. It is noted that the inclusion complex between an electron-rich guest molecule and CB [8] typically requires the presence of an electron acceptor such as methyl viologen (N,N-dimethyl-4,4-bipyridinium, MV 2+ ), 5 because the formation of the ternary complex CB [8]-donor-MV 2+ is driven by the charge transfer (CT) interaction between the electron donor and MV 2+ inside the CB [8] cavity.…”

“…Among them, the inclusion chemistry of CB [8] seems much more interesting, owing to the fact that it can accommodate two identical 3 or different 4 aromatic guests in its cavity. It is noted that the inclusion complex between an electron-rich guest molecule and CB [8] typically requires the presence of an electron acceptor such as methyl viologen (N,N-dimethyl-4,4-bipyridinium, MV 2+ ), 5 because the formation of the ternary complex CB [8]-donor-MV 2+ is driven by the charge transfer (CT) interaction between the electron donor and MV 2+ inside the CB [8] cavity. While the dimerization constant of MV + (methylviologen radical) in the presence of equimolar CB [8] is estimated to be 2 Â 10 7 M À1 , which is much larger than that of the ternary inclusion complex CB [8]donor-MV 2+ (normally 10 3 -10 5 M À1 ).…”

“…It is noted that the inclusion complex between an electron-rich guest molecule and CB [8] typically requires the presence of an electron acceptor such as methyl viologen (N,N-dimethyl-4,4-bipyridinium, MV 2+ ), 5 because the formation of the ternary complex CB [8]-donor-MV 2+ is driven by the charge transfer (CT) interaction between the electron donor and MV 2+ inside the CB [8] cavity. While the dimerization constant of MV + (methylviologen radical) in the presence of equimolar CB [8] is estimated to be 2 Â 10 7 M À1 , which is much larger than that of the ternary inclusion complex CB [8]donor-MV 2+ (normally 10 3 -10 5 M À1 ). As soon as MV 2+ is reduced to MV + , a 2 : 1 inclusion radical dimer (MV + ) 2 / CB [8] will be formed immediately, leading to exclusion of the electron rich guest from the CB [8] cavity simultaneously.…”

Interaction between Cucurbit[n]uril (n=7, 8) and Two Kinds of Viologen Derivatives Containing Coumarin Unit

“…紫精衍生物作为一种典型的缺电子体, 可以和瓜环 形成良好的包结物. Kaifer [16] , Kim [17] 及孙立成课题组 [18] 都有这方面的研究. 我们课题组 [19] Figure 1 1 H NMR spectra of interaction between CB [7] and Figure 2 1 H NMR spectra of interaction between CB [8] and [28,29] , Bruker AVANCE III 400 MHz 超导核 …”