Synthesis, spectroscopic, thermogravimetric and antimicrobial studies of mixed ligands complexes

•Synthesis of mixed ligand complexes of guaifenesin and glycine in 1:1:1 molar ratio.•Guaifenesin acts as monobasic tridentate while electronic and magnetic data proposed an octahedral geometry.•HF method with 3-21G basis set is used to investigate the molecular structure of GFS ligand.•The antibacterial activity was screened of the compounds.•The complexes exhibit considerable anticancer activity against the breast cell line (MFC7).

An interesting series of mixed ligand complexes have been synthesized by the reaction of metal chloride with guaifenesin (GFS) in the presence of 2-aminoacetic acid (HGly) (1:1:1 molar ratio). The elemental analysis, magnetic moments, molar conductance, spectral (UV–Vis, IR, 1H NMR and ESR) and thermal studies were used to characterize the isolated complexes. The molecular structure of GFS is optimized theoretically and the quantum chemical parameters are calculated. The IR showed that the ligand (GFS) acts as monobasic tridentate through the hydroxyl, phenoxy etheric and methoxy oxygen atoms and co-ligand (HGly) as monobasic bidentate through the deprotonated carboxylate oxygen atom and nitrogen atom of amino group. The molar conductivities showed that all the complexes are non-electrolytes except Cr(III) complex is electrolyte. Electronic and magnetic data proposed the octahedral structure for all complexes under investigation. ESR spectrum for Cu(II) revealed data which confirm the proposed structure. Antibacterial screening of the compounds were carried out in vitro on gram positive (Bacillus subtilis and Staphylococcus aureus), gram negative (Escherichia coli and Neisseria gonorrhoeae) bacteria and for in vitro antifungal activity against Candida albicans organism. However, some complexes showed more chemotherapeutic efficiency than the parent GFS drug. The complexes were also screened for their in vitro anticancer activity against the breast cell line (MFC7) and the results obtained showed that they exhibit a considerable anticancer activity.

Graphical abstractGeometry optimized structures of GFS.Figure optionsDownload full-size imageDownload as PowerPoint slide