Novel Diazocrowns with Pyrrole Residue as Lead(II)Colorimetric Probes

Novel 18- and 23-membered diazomacrocycles were obtained with satisfactory yields by diazocoupling of aromatic diamines with pyrrole in reactions carried under high dilution conditions. X-ray structure of macrocycle bearing five carbon atoms linkage was determined and described. Compounds were characterized as chromogenic heavy metal ions receptors. Selective color and spectral response for lead(II) was found in acetonitrile and its mixture with water. Complexation properties of newly obtained macrocycles with a hydrocarbon chain were compared with the properties of their oligoether analogs. The influence of the introduction of hydrocarbon residue as a part of macrocycle on the lead(II) binding was discussed. Selective and sensitive colorimetric probe for lead(II) in aqueous acetonitrile with detection limit 56.1 mu g/L was proposed.

Automated summary

Novel 18- and 23-membered diazomacrocycles were synthesized by diazocoupling of aromatic diamines with pyrrole under high dilution conditions, showing characteristics as chromogenic heavy metal ions receptors. These macrocycles exhibited selective and sensitive color and spectral response for lead(II) in acetonitrile mixtures with water. The introduction of a hydrocarbon residue as part of the macrocycle influenced the lead(II) binding, leading to the proposal of a selective and sensitive colorimetric probe for lead(II) in aqueous acetonitrile with a detection limit of 56.1 μg/L.