• Omprakash Tukaram Sangule

In this study, a novel ligand, cinnamaldehyde thiosemicarbazone (Cin-TSC), was synthesized and thoroughly characterized for its coordination behaviour with Fe(III) ions. The ligand was prepared by refluxing equimolar quantities of cinnamaldehyde and thiosemicarbazide in ethanol, yielding a yellow crystalline solid with a melting point of 173 °C and a calculated molecular weight of 205.284 g/mol. Elemental analysis confirmed the compound's stoichiometry, while antimicrobial screening against Klebsiella pneumoniae indicated moderate bioactivity with a 0.60 cm inhibition zone. The ligand was analyzed using UV-visible and infrared (IR) spectroscopy. A strong absorption peak at 330 nm was observed in the UV-Vis spectrum (ε = 1.250 × 10⁵ L·mol⁻¹·cm⁻¹), and IR spectral data confirmed the presence of key functional groups such as C=S, C=N, N–H, and aromatic moieties. X-ray diffraction (XRD) studies revealed that Cin-TSC crystallizes in the orthorhombic system with high structural order. Complexation studies with Fe(III) were conducted at pH 5 (Optimum pH)using spectrophotometric techniques. The complex exhibited a maximum absorbance at 410 nm with a molar absorptivity of 6.847 × 10² L·mol⁻¹·cm⁻¹. Job’s method and mole ratio analysis both confirmed a 1:2 metal-to-ligand stoichiometry. The dissociation constant of the complex was calculated to be 4.010 × 10⁻¹⁰, corresponding to a high stability constant (β = 2.493 × 10⁹), indicating the strong binding affinity of the ligand toward Fe(III). Beer’s law was obeyed in the concentration range of 8.953 × 10⁻⁵ to 8.953 × 10⁻⁴ M, and Sandell’s sensitivity was determined to be 0.0818 µg cm⁻². Interference studies demonstrated that most divalent metal ions had negligible impact on complexation, whereas chelating agents such as EDTA and acetate ions significantly interfered. Furthermore, Cin-TSC was successfully applied to the spectrophotometric determination of Fe(III) in Panchganga River water samples. The experimentally observed Fe(III) concentration (0.83 ppm) closely matched the calculated value (0.82 ppm), confirming the reliability and accuracy of the method. These findings suggest that Cin-TSC is a promising ligand for the spectrophotometric determination of iron and offers potential for biological, analytical, and environmental water analysis applications.

Cinnamaldehyde thiosemicarbazone, Iron(III) complex, Spectrophotometric determination, Stability constant, UV-Visible spectroscopy, Infrared spectroscopy, Antimicrobial activity.

"Synthesis, Spectroscopic Characterization, and Analytical Applications of Cinnamaldehyde Thiosemicarbazone and Its Fe(III) Complex in Environmental Water Analysis", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.12, Issue 9, page no.a309-a316, September-2025, Available :http://www.jetir.org/papers/JETIR2509038.pdf

"Synthesis, Spectroscopic Characterization, and Analytical Applications of Cinnamaldehyde Thiosemicarbazone and Its Fe(III) Complex in Environmental Water Analysis", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.12, Issue 9, page no. ppa309-a316, September-2025, Available at : http://www.jetir.org/papers/JETIR2509038.pdf