Mechanochemical Synthesis, Characterization and Antimicrobial Activity of Some Organotin (IV) Derivatives of Propan-1,3-Dioic Acid

Three organotin (IV) derivatives of propan-1,3-dioic acid with potassium (K) metal; potassium dibutyltin(IV)propan-1;3-dioate (1), potassium diphenltin(IV)propan-1,3-dioate (2), and potassium triphenltin(IV)propan-1,3-dioate (3) were mechanochemically synthesized by grinding KOH with propan-1,3-dioic acid to give the ligand L: potassium propan-1,3-dioate, followed by reacting the ligand, L with Bu2SnO, Ph2SnO and Ph3SnOH separately. The complexes were purified by recrystallization and purity checked by melting point determination. Characterization of the complexes was done using Fourier Transformed Infrared Spectroscopy (FTIR) and solubility studies. The complexes were screened for antimicrobial activity against four strains of bacteria: Escherichia coli, Klebstella Pneumonia, Salmonella tyhi and Pseudomonas aeruginosa and four fungi strains: Conioplora puteana, Rhizopus spp, Scleratium rofsii and Serpula lacrymans. Ciproflxacin and Fulcin were used as controlled drugs. FTIR spectrum of the ligand showed Vasym(COO) absorption bands which shifted from 1699.7 cm-1 to 1479.8 cm-1, 1640.8 cm-1 and 1703.4 cm-1 in complexes (1), (2) and (3), respectively. These shifts indicated that the carbonyl oxygen were in coordination of the metal ions. Their modes of coordination were found to be bidendate since their ∆υ values obtained were < 200 cm-1. The antimicrobial result showed significant activity (20-27 mm) against the microbes at the minimum inhibition concentrations (MIC) in the range 5-20 µg/mL and minimum bactericidal/fungicidal concentrations (MBC/MFC) of 10 and 20 µg/mL. The order of activity showed by the ligand and complexes is (2)>(1)>(3)>L against bacteria and (3)>(2)>L>(1) against fungi which competed favourably with the control drugs: Ciproflxacin and Fulcin.