Molecular recognition of aliphatic amines by luminescent Zn-porphyrins

Two new porphyrins and their zinc(II) complexes have been synthesized, their photophysical properties studied, and their use in the molecular recognition of amines has been analyzed. The luminescence properties of both series of compounds show a decrease on the luminescence quantum yield of the Zn-derivatives with respect to their corresponding free base porphyrins. Attempts to probe the ability of the compounds to recognise certain biologically relevant drugs revealed that dimethylformamide (DMF) is capable of binding the zinc(II) porphyins. This fact led us to perform sensing experiments of different aliphatic amines, the highest calculated association constant for methyl- and trimethylamine. These properties confirm the sensitivity of porphyrins to the binding of closely related analytes.