Structural, optical, thermal, biological and molecular docking studies of guanidine based naphthoate metal complexes

The present work reports the complexation of few d-block metals with 3-hydroxy-2-naphthoic acid and guanidine which yields corresponding mononuclear complex bis(guaninium) 3-hydroxy-2-naphthoate metal (II) dihydrate of the type M(CN3H5)(2){C10H6(3-O)(2-COO)}].2H(2)O, where M= form Mn(II), Fe(II), Co(II), Ni(II), Cu (II), Zn(II), Cd(II), Pb(II) and Ca(II) of ratio 1:2:4 - metal: acid: base. Characterization of the complexes were done by elemental analysis, IR spectra, UV-Visible spectroscopy, TG-DTA, powder XRD. TG-DTA study reveals various decomposition pattern and thermal stability of the metal complexes. Crystalline nature of the metal complexes is confirmed form powder XRD measurement. SEM coupled with EDAX and AFM confirms the presence of nano-sized metal oxides. Antibacterial studies of the metal complex prove that they are active against Bacillus subtilis and Escherichia coli. Furthermore, molecular docking was carried out for a study of physicochemical properties and to show the binding energy of ligands with proteins.