Novel emissive phenylurea-based macrocyclic chemosensor: Synthesis, fluorescent and complexation studies

A new emissive macrocycle ligand bearing three phenylurea groups (L1) has been synthesized and fully characterised. Several mononuclear complexes with nitrate, perchlorate and tetrafluoroborate salts of transition and post-transition metals (Cu2+, Ni2+, Co2+, Zn2+ and Cd2+) were synthesized and characterised. For comparative purposes, the coordination ability of two nonfluorescent macrocyclic ligands (L2 and L3) containing three nitrophenylurea pendant-arms towards the same metal ions were studied. The interaction with transition and post-transition metal ions, and anions was explored in solution by UV–Vis and emission spectroscopy with ligand L1. All new compounds were characterised by microanalysis, IR, UV–Vis and fluorescence emission, FAB and ESI mass spectrometry and conductivity measurements.