Studies on Synthesis and Spectral Characterization of Some Transition Metal Complexes of Azo-Azomethine Derivative of Diaminomaleonitrile

Abstract

New complexes of 2,3-bis(5-(4-chlorophenyl)diazenyl)-2-hydroxybenzylideneamino)maleonitrile (CDHBDMN) with VO(II), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) were synthesized and characterized by analytical and physicochemical techniques, that is, elemental analyses, molar conductivity, UV, IR, EPR, 1 H-NMR spectra, magnetic susceptibility and also by aid of scanning electron microscopy (SEM), nonlinear optical study (NLO), �uorescence spectral studies, and solvatochromic behaviors. Electronic and magnetic susceptibility measurements of the complexes indicate square pyramidal geometry for VO(II), octahedral for Ni(II), and square planar geometry for all the other complexes. e EPR spectral data provide information about their structures on the basis of Hamiltonian parameters and the degree of covalency. ese metal complexes were also tested for their antibacterial and antifungal activities to assess their inhibiting potential. Metal-mediated �uorescence enhancement is observed on complexation of the azo Schiff base ligand. e synthesized compounds were investigated for nonlinear optical properties, and the surface morphology of the Cu(II) complex was studied by scanning electron microscopy.

Syntheses of Coordination Compounds of (±)-2-Amino-3-(4-Hydroxyphenyl)Propionic Acid, Mixed Ligand Complexes and Their Biological Activities

“…Absorption at 259 and 318 nm is associated with π → π* transition of the ligand [43] [44] Its magnetic moment of 1.066 BM is lower than that expected for Co(II) ion may be ascribed to antiferromagnetism which is due to the interaction between electron spins on neighbouring metal ions or polymerization. This is similar to that obtained for compound 1 [34] [35] [36].…”

“…The electronic spectrum of compound 1 exhibited two bands at 512 nm and 735 nm corresponding to 2 A 1g → 2 B 2g and 2 A 1g → 2 E 1g respectively On the basis of simplest model three spin-allowed bands are expected in a four coordinate cobalt(II) complex, that is, 4 A 2 (F) → 4 T 2 (F), 4 A 2 (F) → 4 T 1 (F), and 4 A 2 (F) → 4 Usually such complexes show two bands between 830 and 625 nm, which can be assigned to 4 A 2 (F) → 4 T 2 (F) and 4 A 2 (F) → 4 T 1 (F), respectively; 4 A 2 (F) → 4 T 1 (P) is usually observed as a well-defined shoulder at about 550 nm [31]. [36]. The spectrum for the cobalt(II) complex of the mixed ligand, compound 2, showed two bands at 460 nm and 620 nm corresponding to the transitions 3 A 2 g → 3 T 2 g and 4 A 2 g → 3 T 1 g respectively for octahedral geometry [27].…”

Mixed-Ligand Ni(II), Co(II) and Fe(II) Complexes as Catalysts for Esterification of Biomass-Derived Levulinic Acid with Polyol and in Situ Reduction via Hydrogenation with NaBH4

“…The SEM investigations checked the surfaces of the metal complexes that exhibited a small to medium particle, which have a tendency to agglomerate formation with different shapes analogous with the starting materials [63]. In general, the SEM photograph displays a single phase formation with well-defined, grain-like shapes being particle sized in the range of 0.5 µm [64]. In this context, the present investigation represents a unique pattern of a metal-organic framework assembly exhibiting that of a nanostructure.…”

Synthesis, Characterization, Analytical and Cytotoxic Studies of N,N′‐Bis(2‐Hydroxynaphthylidene)‐4‐chlorophenyl Methanediamine and Its Co(II), Ni(II) and Cu(II) Complexes

“…In the case of BHNCPMD, the multiplet which extends from d6.69 ppm to 8.95 ppm is due to the aromatic ring protons of the Schiff base ligand. [15] The two phenolic protons which are under similar chemical environment appear as singlet at d10.81 ppm. [16] The signal at d10.00 ppm corresponds to the azomethine protons of the ligand.…”