A mutually stabilized host-guest pair.

Authors :: Zhang C
Wang H
Zhong J
Lei Y
Du R
Zhang Y
Shen L
Jiao T
Zhu Y
Zhu H
Li H
Li H
Source :: Science advances [Sci Adv] 2019 Nov 01; Vol. 5 (11), pp. eaax6707. Date of Electronic Publication: 2019 Nov 01 (Print Publication: 2019).
Publication Year :: 2019
Abstract: By using click chemistry, a hexacationic cage was synthesized. The cage contains two triscationic π-electron-deficient trispyridiniumtriazine (TPZ <superscript>3+</superscript> ) platforms that are bridged in a face-to-face manner by three ethylene-triazole-ethylene linkers. A diversity of π-electron-rich guests can be recognized within the pocket of the cage, driven by host-guest π-π interactions. The cage cavity acts as a protecting group, preventing an anthracene guest from undergoing Diels-Alder reaction. Under ultraviolet (UV) light, the pyridinium C─N bonds in TPZ <superscript>3+</superscript> platforms are polarized and weakened, resulting in the occurrence of cage decomposition via β-elimination. Guest recognition could help to prevent this UV-stimulated cage decomposition by suppressing the excitation of the TPZ <superscript>3+</superscript> units.<br /> (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)