International Science Community Association Research Journal of Chemical Sciences 15 2 2025 06 18 Speciation behaviour of multinuclear chelates involving biologically active transition metal ions with L-2-aminopropanoic acid and 6-methyl-2-thiouracil 28 34 EN Gupta Swaroopa Rani N. 1 Department of Chemistry, Brijlal Biyani Science College, Amravati, Maharashtra, India T. Sumathi 1 Department of Physics, Annamalai University, Annamalainagar – 608 002, India S. Parkavi 2 Department of Physics, Annamalai University, Annamalainagar – 608 002, India C. Soundaraj 3 Department of Physics, Annamalai University, Annamalainagar – 608 002, India K. Jetruth Mary Alphonsa 4 Department of Physics, Annamalai University, Annamalainagar – 608 002, India Shukla V.P. 1 Department of Chemistry Bipin Bihari College Jhansi-284001, India Kumar Anil 2 Delhi Technological University, Delhi-110042, India Bharti Karnam 3 Department of Chemistry Bipin Bihari College Jhansi-284001, India > Research Paper 2024 12 19 2025 06 18 The complexation properties of L-2-aminopropanoic acid [Alanine,(Ala)] to form multinuclear chelates with significant biologically effective transition metal ions (CuII, NiII, ZnII, CoII) in presence of 6-methyl-2-thiouracil (MTU) have been determined pH-metrically in biotiically relevant conditions. Formation constants of chelates at 35±10C and at constant ionic strength 0.1M NaNO3 have been calculated using Stability Constants of Generalized Species (SCOGS) computer program. The graph and speciation equilibria were elucidated with the help of ORGIN 6.1. Solution of di positive transition metal ions copper, nickel, zinc, cobalt (0.01M) were processed and standardized by complexometric titration Pyrimidine base derivative (methyl thiouracil) 0.01M solution was prepared by dissolving the ligand into one equivalent of alkali sodium hydroxide (NaOH). Whereas solution of amino acid alanine (0.01M) were prepared in double distilled water only. The molar ratio of metal and ligand endeavoured was kept 1:1:1 for ternary mixture and 1:1:1:1 for quaternary mixtures. Multinuclear chelates understudy demonstrate the formation of multimetal-multiligand complexes of stoichiometry M1M2L1L2 in addition to ML1L2, ML1 and ML2 complexes for all metal ions. The pH titration curves, species distribution curves, hydroxo complex species and overall stability order found for heterobinuclear chelates are discussed in terms of Irving-Williams order. Solution structures of metal complexes with said ligands have been compared and discussed. Copyright@ International Science Community Association