Complexation Study of Synthesized Pharmacological Organic Ligands with Samarium

• Published in: Russian journal of inorganic chemistry Vol. 65; no. 14; pp. 2046 - 2052
• Main Authors: Zamzam Taher Omar (Al-Ahdal), Jadhav, Shivaji, Mohsin, Mohamad, Faizaa, A. Saif, Rai, Megha
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2020; Springer Nature B.V
• Subjects: Biological activity; Chemical analysis; Chemistry; Chemistry and Materials Science; Complexation; Coordination Compounds; Ethanol; Exothermic reactions; Imines; Inorganic Chemistry; Ligands; Methylene; NMR; Nuclear magnetic resonance; Samarium; Sodium perchlorate; Stability analysis; Synthesis; Gibbs free energy change; samarium; organic ligands; pH-metric technique; enthalpy change
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023620140053

This research describes the formation of samarium complexation with organic ligands (Schiff bases of anti-mycobacterial agent isonicotinic acid hydrazide) through pH-metric technique at 25, 35, and 45°C in 70% (v/v) ethanol/water medium at 1M (NaClO 4 ) ionic strength. Organic ligands have been synthesized and their structures have been confirmed by various characterization techniques such as TLC, MP, IR, 1 H NMR, 13 C NMR, UV-Vis spectroscopies and elemental analysis. They have been evaluated for biological activity against gram positive, gram negative bacteria, and fungi showing moderate to significant results. Complexation study of these binary complexes has been evaluated and calculated using Calvin–Bjerrum technique. The order of stability constant has been found to be as follows N -[( E )-(4-hydroxy-3-methoxyphenyl)methylene]isonicotinohydrazide (L 2 ) < N -[( E )-(4-chlorophenyl)methylene]isonicotinohydrazide (L 1 ) < N -[( E )-(4-hydroxyphenyl)methylen]isonicotinohydrazid (L 4 ) < N -[( E )-(2-hydroxyphenyl)methylen]isonicotinohydrazid (L 5 ) < N -[( E )-(2-nitrophenyl)methylen]isonicotinohydrazide (L 3 ). Thermodynamic parameters associated with the samarium complexation have been observed to be negative in Δ H and Δ G . This indicates the exothermic reaction in complexation.