(Oligo)thienyl-imidazo-benzocrown ether derivatives : synthesis, photophysical ...

• Author(s): Batista, Rosa M. F. ; Oliveira, Elisabete ; Costa, Susana P. G. ; Lodeiro, Carlos ; Raposo, M. Manuela M. ; Ferreira, R. Cristina M.
• Date: 2011
• Persistent ID: http://hdl.handle.net/1822/15117
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Benzo-15-crown-5 ether; (oligo)thiophene; Imidazole; Fluorescent chemosensors; Hg2+; Pd2+; CHEF effect
• Document Type: Article
• Language: English

Description

A series of novel (oligo)thienyl-imidazobenzocrown ethers were synthesised through a simple method and evaluated as fluorimetric chemosensors for transition metal cations. Interaction with Ni2+, Pd2+, and Hg2+ in ACN/DMSO solution (99:1) was studied by absorption and emission spectroscopy. Chemoselectivity studies in the presence of Na+ were also carried out and a fluorescence enhancement upon chelation (CHEF) effect was observed following Hg2+ complexation. Considering that most systems using fluorescence spectroscopy for detecting Hg2+ are based on the complexation enhancement of the fluorescence quenching (CHEQ) effect, the present work represents one of the few examples for sensing of Hg2+ based on a CHEF effect.