Fluorescent recognition of small organic molecules based on supramolecular aggregation/deaggregation of planar Cu(II) coordination complex

A Cu(II) coordination complex (1) with Schiff ligand derived from diaminomaleonitrile was synthesized and characterized, in which the ligand is rigid, planar and conjugated. The complex 1 displays an interesting fluorescent property relative to solvents which can be turned-on by CH₂Cl₂ and CHCl₃ solvent molecules. The mechanism of this selective fluorescence emission has been studied based on the crystal structure and the spectrum analysis. The tuning on and off fluorescence of complex 1 can be controlled by the process of supramolecular aggregation/deaggregation in different solvents.