Molecular switches of fluorescence operating through metal centred redox couples

✍ Scribed by Raffaella Bergonzi; Luigi Fabbrizzi; Maurizio Licchelli; Carlo Mangano

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 241 KB
• Volume: 170
• Category: Article
• ISSN: 0010-8545
• DOI: 10.1016/s0010-8545(98)00069-1

✦ Synopsis

Three-component molecular systems (redox active subunit)-spacer-( light-emitting fragment) can operate as fluorescence switches, following the alternate addition of an oxidizing agent and a reducing agent (or the adjustment of the potential of the working electrode in an electrolysis experiment). The redox active subunit typically consists of a metal centred redox couple (M(n+1)+/Mn+), encircled by a macrocyclic receptor, and switching efficiency requires that one of the two oxidation states quenches the proximate fluorophore and the other does not. Four ON/OFF systems, based on either the CuII/CuI or NiIII/NiII couple, will be discussed. The nature of the quenching process responsible for the OFF state, either electron transfer or energy transfer, is related to the length and to the flexibility-rigidity of the spacer.