Design, synthesis, characterization and antibacterial and antifungal activity of a new 2-{(E)-[(4-aminophenyl)imino]-methyl}-4,6-dichlorophenol and its complexes with Co(II), Ni(II), Cu(II) and Zn(II): An experimental and DFT study

Abstract

In this study, the complexes of Co (II), Ni (II), Cu (II) and Zn (II) with 2-(E)-(4-aminophenylimino)methyl-4,6-dichlorophenol were prepared and characterized by physical, spectral and analytical data. The metal: ligand stoichiometric ratio is 1:2 in all the complexes. The results suggested that the Schiff bases are coordinated to the metal ions through the phenolic oxygens and azomethine nitrogen to give mononuclear complexes. Their structures were elucidated on the basis of elemental analysis, IR, 1H and 13C NMR spectra, UV-VIS, magnetic susceptibility measurements and thermogravimetric analyses. Both the antibacterial and antifungal activities and MIC values of compounds were reported. Among the tested compounds, the most effective compound providing a MIC value of 64 ?g/mL is Zn(L)2 against C. tropicalis and B. subtilis. The theoretically optimized geometries of complexes have tetrahedral structures. The computed stretching frequencies of C=N, C-O and N-H bonds were found to be in good agreement with experimental data. All calculated frequencies fall within about 5% of the experimental frequency regions.

Catalytic investigation of Pd(II) complexes over Heck-Mizoroki reaction: Tailored synthesis, characterization and density functional theory

“…[Pd II L1(imdz)2]Cl→ [Pd II L1(imdz)2] + + Cl¯ In the FT-IR spectra of complexes, the band observed at ~3217 cm -1 , assigned for -OH vibration in ligands completely vanished and a new band at lower frequency appeared at ~534 cm -1 , which was assigned to Pd-O. 24 The ap-O n L i n e F i r s t pearance of this band indicates the bonding of metal with phenolic oxygen. The band due to azomethine HC=N groups was shifted downwards in complexes and observed at ~1602 cm -1 , which confirms the coordination of azomethine nitrogen with metal.…”

Oxovanadium(IV) complexes of the pyridoxal Schiff bases: Synthesis, experimental and theoretical characterizations, QTAIM analysis and antioxidant activity

“…The calculated structural parameters are in good consistency with the corresponding values reported for the similar compounds. 2,3,5,6,8,[16][17][18][19][27][28][29][30] Table S-I of the Supplementary material. The C=N stretching vibration of the azomethine group results in an intensive band at 1660--1500 cm -1 region of the IR spectra of the Schiff bases.…”

“…The C=N stretching vibration of the azomethine group results in an intensive band at 1660--1500 cm -1 region of the IR spectra of the Schiff bases. 2,5,6,8,18,19,27,[29][30][31][32][33][34][35] The symmetrical stretching modes of C6=N2 and C10=N4 bonds cause an intensive band at 1628 and 1650 cm -1 in the IR spectra of the free H 2 A and H 2 B Schiff bases, respectively. Due to coordination of the N2 and N4 azomethine nitrogens to V 4+ , electron density of the C6=N2 and C10=N4 bonds is decreased.…”

“…OXOVANADIUM(IV) COMPLEXES OF PYRIDOXAL SCHIFF BASES 43 stretching vibrations of these bonds appeared at lower energies than for the free Schiff bases, 1609 and 1633 cm -1 for [VO(A)] and [VO(B)], respectively. 2,5,6,8,18,19,[27][28][29]31 Overlapping of the O-H, N-H and C-H stretching vibration modes results in a band broading in the 3600-2000 cm -1 region of the IR spectra. 8,18,19,27--29,31,33-35 This region of the [VO(A)] and [VO(B)] spectra has been assigned.…”

“…The Schiff bases and their complexes are of great importance in many areas especially in the biology with activities such as antibacterial, [1][2][3] antifungal, 2 antimicrobial, 4 antidiabetic 5 and anticancer. 6,7 Among them, the oxovanadium(IV) complexes of the Schiff bases exhibit beneficial catalytic 8,9 and biological activities such as the antimicrobial 3 and antidiabetic.…”