Electrochemistry of Rhodanine Derivatives as Model for New Colorimetric and Electrochemical Azulene Sensors for the Detection of Heavy Metal Ions

Rhodanine (R) is a heterocycle having complexing properties for heavy metal (HM) ions. Considering the similar electron-donating character of diethylaminobenzene and azulene, electrochemical characterization (Z)-5-(azulen-1-ylmethylene)-2-thioxo-thiazolidin-4-one (R1) 5-(4 diethylamino-benzylidene)-2-thioxo-thiazolidin-4-one (R2) was performed to establish their common features. Chemically modified electrodes based on R1 R2 were compared HM recognition. Evidence formation films provided by scanning controlled potential electrolysis, recognition experiments using films. Parallel studies analysis HMs complexation in solution UV-Vis. The analogy between created premise easier selection compounds certain applications. performance chemically evaluated as detection limits HMs. azulene monomer proved be best candidate Pb(II) detection, being about eight times more sensitive than R2. However, solution, good choice optical measurements, higher absorption coefficient. These results support two ligands different behaviors homogeneous heterogeneous systems.