A macrocyclic ligand (H2L) containing two o,o′-bis(iminomethyl)phenol and two calixarene head units has been synthesized and its coordination chemistry towards divalent Ni and Zn investigated. The new macrocycle forms complexes of composition [ML] (M=Zn, M=Ni) and [ZnL(py)2], which were characterized by elemental analysis; IR, UV/Vis, and NMR spectroscopy; electrospray ionization mass spectrometry (ESI-MS); and X-ray crystallography (for [ZnL(py)2] and [NiL]). H2L allows the sensitive optical detection of Zn2+ among a series of biologically relevant metal ions by a dual fluorescence enhancement/quenching effect in solution. The fluorescence intensity of the macrocycle increases by a factor of ten in the presence of Zn2+ with a detection limit in the lower nanomolar region.
Bibliographical noteFunding Information:
We are thankful to Prof. Dr. H. Krautscheid for providing facilities for X-ray crystallographic measurements. The financial support by the German Federal Ministry of Education and Research (BMBF, r4project SE-FLECX, 033R132A) is gratefully acknowledged.
All Science Journal Classification (ASJC) codes
- Organic Chemistry