Cooperative Ratiometric Chemosensors:  Pinwheel Receptors with an Integrated Fluorescence System

Abstract

The synthesis and fluorescent properties of a second generation cooperative chemical sensor are described. The sensor has two interacting binding pockets for cooperative recognition of two analytes. Cooperative binding activates a ratiometric fluorescent response via formation of an excimer. Binding was characterized by NMR, absorption, and fluorescence spectroscopy. The advantages of separating the recognition elements from the fluorescent response elements are discussed.

Artificial Molecular Machines

“…A number of different fluorescent sensors reporting conformational changes have been synthesized on the basis of energy transfer, 1272 − 1274 excimer formation, 1275 − 1282 or charge transfer mechanisms. 1283 − 1286 Optical responses have been obtained by simple stimuli-dependent conformational change, 796 , 1262 , 1273 , 1275 , 1287 − 1289 folding processes, 1276 − 1278 , 1290 shuttling, 799 , 1272 , 1283 − 1285 , 1291 − 1294 switching, 1273 and transitions between coiled and helical structures. 1295 Optical outputs have been used to develop molecular logic gates.…”

A dual channel chemodosimeter for Hg2+ and Ag+ using a 1,3-dithiane modified BODIPY

“…We suppose that Ag + can coordinate with the sulphur atoms of the thioacetal moiety of 1, due to the fact that Ag + exhibits a moderate coordination ability compared with Hg 2+ . 81,82 This inhibits PET quenching of the fluorescence and leads to restoration of emission. The detection limit for sensing Ag + was found to be 0.65 mM.…”

Fluorescence sensing systems for gold and silver species

“…In 2001, Glass and co-workers demonstrated a cooperative binding-induced excimer formation using two pinwheel systems. 177 The systems contained four ethylenediamine moieties, which cooperatively interacted with Ag(I) and brought the attached fluorophores in close proximity to induce the excimer emission. Among several fluorophores tested only two fluorophores could induce the excimer band, namely naphthylsulfonanilide 81 and pyrenyl acetanilide 82 (Fig.…”