Fullerene–Coumarin Dyad as a Selective Metal Receptor: Synthesis, Photophysical Properties, Electrochemistry and Ion Binding Studies

Abstract

A coumarin derivative with a malonate unit has been synthesized and used for the preparation of a fullerene-coumarin dyad through the Bingel cyclopropanation method. The newly synthesized dyad is soluble in organic solvents and has been fully characterized with traditional spectroscopic techniques. Electronic interactions between the two components of the dyad were probed with the aid of UV/Vis spectroscopy, fluorescence emission, and electrochemistry measurements. Our studies clearly show the presence of electronic interactions between C(60) and modified coumarin in the ground state; efficient electron-transfer quenching of the singlet excited state of the coumarin moiety by the appended fullerene sphere was also observed. Time-resolved fluorescence measurements revealed lifetimes for the coumarin-C(60) dyad at a maximum of 50 ps, while the quantum yield was reaching unity. Additionally, the redox potentials of the C(60)-coumarin dyad were determined and the energetics of the electron-transfer processes were evaluated. Finally, after alkaline treatment of C(60)-coumarin, which resulted in the deprotection of carboxylate units, the dyad was tested as a metal receptor for divalent metal cations; ion competition studies and fluorescence experiments showed binding selectivity for lead ions.

Macrocyclic pentamers functionalised around their periphery as potential building blocks

“…Platinum on carbon (Pt/C) is oen used for reduction of nitro to amine in a mild condition without affecting other adjacent groups. [28][29][30] Here, Pt/C was also successfully employed to reduce the nitro group under ambient condition using an H 2 balloon without loss of the benzyl group to produce 12 in excellent yield (Scheme 1, vii).…”

Review—Recent Advances in Electrochemical Sensing of Lead Ion

“…For zerodimensional carbon materials fullerene and carbon quantum dots, due to their unique optical properties, they are often used in the optical field. 74,75 We will not discuss them too much here. Onedimensional and two-dimensional carbon materials are the carbon nanomaterials which often used for electrochemical detection of Pb 2+ .…”

Nucleophilic cyclopropanation of [60]fullerene by the addition–elimination mechanism

“…The malonate derivative of coumarin that was synthesized, which contains a benzothiazole chromophore block as a continuation of the p-conjugated system of the coumarin skeleton, undergoes a Bingel-Hirsch reaction to give fullerenecoumarin diad 254 (Scheme 71): 133 The electron interactions between the two components of diad 254 were studied by UV/Vis spectroscopy, uorescence emission and electrochemical measurements. Studies clearly show the existence of electronic interactions between C 60 and modied coumarin in the ground state; efficient electron-transfer quenching of the singlet excited state of the coumarin moiety by the appended fullerene sphere was also observed.…”