A fluorescent chemosensor signalling only Hg(II) and Cu(II) in water

Geometric immobilization of polyamine ligands is expected to change their binding properties toward practical ion discrimination. Chemosensor 5 senses only two Transition metal ions in water- Hg(II) (K-d less than or equal to 1 mu M) and Cu(II) (K-d 56 mu M)- which can be compared with bindings of a nonimmobilized reference compound (9-(trpnmethyl)-anthracene; 3) with Hg(II) (K-d 14 mu M) and Cu(II) (K-d 39 mu M). A related bridged cyclen derivative (7) showed no effect on fluorescence by any metal ion examined. (C) 1997 Elsevier Science Ltd.