Synthesis, Characterization and Antimicrobial Studies of N¹‐[(1E)‐1‐(2‐Hydroxyphenyl) ethylidene]‐2‐oxo‐2H‐chromene‐3‐carbohydrazide and its Metal Complexes

Abstract

A new complexes of the type ML, MʹL and M″L [where M=Cu(II), Co(II), Ni(II) and Mn(II), Mʹ=Fe(III) and M″=Zn(II), Cd(II) and Hg(II) and L=N1-[(1E)-1-(2-hydroxyphenyl)ethylidene]-2-oxo-2H-chromene- 3-carbohydrazide (HL)] Schiff base have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, IR,1H NMR, UV-Visible and ESR data. The studies indicate the HL acts as doubly monodentate bridge for metal ions and form mononuclear complexes. The complexes Ni(II), Co(II), Cu(II) Mn(II) and Fe(III) complexes are found to be octahedral, where as Zn(II), Cd(II) and Hg(II) complexes are four coordinated with tetrahedral geometry. The synthesized ligand and its metal complexes were screened for their antimicrobial activity.

Synthesis, Spectroscopic Characterization, and Biological Evaluation Studies of 5-Bromo-3-(((hydroxy-2-methylquinolin-7-yl)methylene)hydrazono)indolin-2-one and Its Metal (II) Complexes

“…In ligand seven aromatic protons have been observed in the region δ (6.9–7.5) (m, 7H) as a multiplet, and it is shifted downfield in the Zn(II), Cd(II), and Hg(II) complexes. The signals observed at δ (2.5) are due to methyl protons that remain almost unaffected in Zn(II), Cd(II), and Hg(II) complexes indicating the nonparticipation of these groups in coordination [ 21 ].…”

“…They have been studied with the view to obtain more information on stereochemistry of the complexes and to procedure more support for the conclusion, deduced with the help of magnetic data. The Co(II) complex of the electronic absorption bands appears at 15384 and 20000 cm −1 due to 4 T 1g (F) → 4 A 2g (F) ( ν 2 ) and 4 T 1g (F) → 4 T 2g (P) ( ν 3 ) transitions, respectively, in an octahedral environment [ 22 ]. The band ν 1 could not be observed because of its very low intensity.…”

“…This is less than one, suggesting partial covalency in the metal ligand bond. The values Dq, β , β %, ν 2 / ν 1 , and LFSE suggest the octahedral geometry for Co(II) complex [ 24 ]. The Co(II) complex displays a magnetic moment value of 4.88 BM, which is within the range of 4.46–5.53 BM.…”

Synthesis, spectroscopic characterization, and thermal studies of novel Schiff base complexes: theoretical simulation studies on coronavirus (COVID-19) using molecular docking

“…To assess the biological profile, another series of antimicrobial agents based on metals with a [(1E)-1-(2-hydroxyphenyl)ethylidene]-2-oxo-2H-chromene-3-carbohydrazide Schiff base possessing a NOO donor system was synthesized and thoroughly analyzed. Cd(II) complex showed the maximum zone of inhibition (18 and 16 mm) against E. coli and A. flavus organisms compared to [Cd(L)Cl 2 ]2H 2 O complex which showed the maximum zone of inhibition (27 and 31 mm) [ 37 , 38 ]. Co(II) complex of the same SB showed the maximum zone of inhibition (12 mm) against Staphylococcus aureus compared to [Co(L)H 2 OCl]Cl·6H 2 O complex which showed the maximum zone of inhibition (20 mm) [ 38 ].…”

“…Cd(II) complex showed the maximum zone of inhibition (18 and 16 mm) against E. coli and A. flavus organisms compared to [Cd(L)Cl 2 ]2H 2 O complex which showed the maximum zone of inhibition (27 and 31 mm) [ 37 , 38 ]. Co(II) complex of the same SB showed the maximum zone of inhibition (12 mm) against Staphylococcus aureus compared to [Co(L)H 2 OCl]Cl·6H 2 O complex which showed the maximum zone of inhibition (20 mm) [ 38 ].…”