New zinc(ii) metalloporphyrin: molecular structure, spectroscopic characterization, electrochemical sensing of dopamine, and catalytic dye degradation†

This work is a continuation of the series of studies aimed at studying the electronic and structural properties of divalent metal porphyrin complexes, especially zinc(II) metalloporphyrins. In this perspective, we have prepared the [Zn(TMPP)(4,4′-bpy)]·CHCl₃ (I) coordination compound, where TMPP is the meso-tetra(para-methoxyphenyl)porphyrinate and 4,4′-bpy is the 4,4′-bipyridine. The UV/Vis, fluorescence, IR and ¹H NMR spectroscopic techniques, ESI-HRMS mass spectrometry investigation as well as a single crystal X-ray diffraction study were used to characterize the title compound. Notably, we demonstrated the ability of this zinc(II) metalloporphyrin to degrade the methylene blue (MB) dye, examining several influencing factors, including pH, temperature and initial dye concentration. Additionally, complex I exhibited remarkable efficiency in degrading MB under blue LED irradiation. Beyond catalytic applications, this compound was successfully employed as an electrochemical sensor for the detection of dopamine (DA) using the square wave voltammetry (SWV) method, showcasing its multifunctional capabilities.