Electronic Spectral Studies Research Articles

Synthesis, characterization, DNA binding and cleavage studies of mixed-ligand copper (II) complexes

New two copper complexes of type [Cu(Bzimpy)(L)H2O]SO4 (where L=2,2′ bipyridine (bpy), and ethylene diamine (en)), Bzimpy=2,6-bis(benzimidazole-2yl)pyridine have been synthesized and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, mass, IR, electronic and EPR spectral studies. Based on elemental and spectral studies six coordinated geometries were assigned to the two complexes. DNA-binding properties of these metal complexes were investigated using absorption spectroscopy, fluorescence spectroscopy, viscosity measurements and thermal denaturation methods. Experimental studies suggest that the complexes bind to DNA through intercalation. These complexes also promote the cleavage of plasmid pBR322, in the presence of H2O2.

Spectroscopic characterization of Lanthanoid derived from a hexadentate macrocyclic ligand: Study on antifungal capacity of complexes

Complexes of Ce(III), Nd(III), Sm(III) and Eu(III) were synthesized with NO-donor macrocyclic ligand, i.e. 3,5,13,15,21,22-hexaaza-2,6,12,16-tetramethyl-4,14-dithia-tricyclo[15.3.1.1(7-11)]docosane-1(21),2,5,7,9,11(22),12,15,17,19-decaene. The ligand was obtained by the condensation of 2,6-diacetylpyridine with thiourea and characterized by elemental analysis, mass, IR and 1H NMR spectral studies. All the complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, mass, electronic spectral techniques and thermal studies. The ligand acts as a hexadentate and coordinated through four nitrogen atoms of azomethine groups and two nitrogen atoms of pyridine ring. The value of spectral parameters i.e. nephelauxetic effect (b), covalency factor (b1/2), Sinha parameter (δ%) and covalency angular overlap parameter (η) account for the covalent nature of the complexes. The macrocyclic ligand and its Lanthanoid were tested in vitro against two plant pathogenic fungi in order to assess their antifungal capacity.

Estimation of Excited State Dipolemoments from Solvatochromic Shifts–Effect of pH

Multicomponent, highly efficient, catalytic synthesis of some polysubstituted imidazole under solvent-free condition is reported. Characterization of polysubstituted imidazole have been carried out by X-ray diffraction (XRD) and spectral techniques. Electronic spectral studies reveal that their solvatochromic behavior depends not only on the polarity of the medium but also on the hydrogen bonding properties of the solvents. Specific hydrogen bonding interaction in polar solvents modulated the order of the two close lying lowest singlet states. The solvent effect on both the absorption and emission spectral results have been analyzed by multiple parametric regression analysis. Solvatochromic effects on the emission spectral position indicate the charge transfer (CT) character of the emitting singlet states both in a polar and a non polar environment. The fluorescence decays for the imidazole fit satisfactorily to a single exponential kinetics. The prototropic studies of N,N-dimethyl-4-(1,4,5-triphenyl-1H-imidazol-2-yl)naphthalen-1-amine (DTINA) reveal that two monocations [imidazole nitrogen protanated (MC1) and dimethylamino nitrogen protanated (MC2)] and a dication [both imidazole nitrogen and dimethylamino nitrogen protanated (DC)] are formed by protonation in both ground and excited states. These observations are in consistent with quantum chemical calculations.

Synthesis, structure and molecular docking studies of dicopper(ii) complexes bridged by N-phenolato-N′-[2-(dimethylamino)ethyl]oxamide: the influence of terminal ligands on cytotoxicity and reactivity towards DNA and protein BSA

Two dicopper(II) complexes bridged by N-phenolato-N′-[2-(dimethylamino)ethyl]oxamide (H3pdmaeox) and end-capped with 2,2′-diamino-4,4′-bithiazole (dabt) and 2,2′-bipyridine (bpy), respectively, namely [Cu2(pdmaeox)Cl(CH3OH)(dabt)]·CH3OH (1) and [Cu2(pdmaeox)(bpy)(H2O)]-(pic)·H2O (2) (where pic− denotes the picrate anion) have been synthesized. Complex 1 was characterized by elemental analysis, molar conductivity measurements, IR and electronic spectral studies, and single-crystal X-ray diffraction. The crystal structure analyses reveal that the dissymmetric unit of complex 1 contains a neutral dicopper(II) complex moiety [Cu2(pdmaeox)Cl-(CH3OH)(dabt)], in which the cis-pdmaeox3− ligand bridges two copper(II) ions with the separation of 5.2238(19) A. Through hydrogen bonding interactions, complex 1 molecules are assembled into 3D supramolecular structures. The structure and DNA-binding activities of complex 2 have been reported in our previous paper. However, its other properties were not studied. In order to gain some insight into the structure–activity relationship, the reactivities towards DNA and protein of the two dicopper(II) complexes are studied both theoretically and experimentally. The DNA docking study suggests that all the two dicopper(II) complexes can interact with DNA through the minor groove, and the binding affinity follows the order of 1 > 2, which is further validated by spectral titration, electrochemical techniques, and viscosity measurements. Bovine serum albumin (BSA) binding activity studies revealed that the two dicopper(II) complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism with the ratio of the dicopper(II) complex to BSA being 1 : 1, and the most possible binding site is in the proximity of Trp134. The in vitro anticancer activities indicate that the two dicopper(II) complexes are active against the selected tumor cell lines, and the order of in vitro anticancer activities is consistent with the DNA-binding affinities. The influence of structural variation of the terminal ligands in the dicopper(II) complexes on DNA-binding modes and anticancer activities is preliminarily discussed.

Synthesis, Spectral Characterization and Biological Evaluation of Chromium(III) Complexes of Schiff Base

Complexes of chromium(III) metal ion with schiff base i.e. 2,3,9,10 tetraphenyl-1,4,8,11-tetra- azacyclotetradeca-1,3,8,10 tetraene. (BPD) 2,4,10,12-tetramethyl-1,5,9,13-tetraazacyclohexadeca- 1,4,9,12 tetraene. (ADP) 2,3,9,10 tetramethyl 1,4,8,11 tatraazatetredeca-1,3,8,10 tetraene (DDP) have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, electronic and epr spectral studies. On the basis of elemental analysis the complexes were found to have composition CrLX3 (X = Cl-, , NCS-), Molar conductance, measured in DMF solution of these complexes indicates that the complexes are 1:1 electrolytes in nature, therefore the complexes may be formulated as [CrLX2]X. These complexes show magnetic moment in the range of 3.80 - 3.84 B.M. corresponding to three unpaired electrons. EPR and electronic spectral studies reveal that the complexes possess six-coordinated octahedral geometry. The ligand field parameters were calculated using various energy level diagrams. In vitro synthesized compounds and metal salts have also been tested against some species of plant pathogenic fungi and bacteria in order to assess their antimicrobial properties.

Synthesis, Characterization, and Biological Activity of N (')-[(Z)-(3-Methyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazol-4-ylidene)(phenyl)methyl]benzohydrazide and Its Co(II), Ni(II), and Cu(II) Complexes.

Reaction of 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one and benzoyl hydrazide in refluxing ethanol gave N ′-[(Z)-(3-methyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazol-4-ylidene)(phenyl)methyl]benzohydrazide (HL1), which was characterized by NMR spectroscopy and single-crystal X-ray structure study. X-ray diffraction analyses of the crystals revealed a nonplanar molecule, existing in the keto-amine form, with intermolecular hydrogen bonding forming a seven-membered ring system. The reaction of HL1 with Co(II), Ni(II), and Cu(II) halides gave the corresponding complexes, which were characterized by elemental analysis, molar conductance, magnetic measurements, and infrared and electronic spectral studies. The compounds were screened for their in vitro cytotoxic activity against HL-60 human promyelocytic leukemia cells and antimicrobial activity against some bacteria and yeasts. Results showed that the compounds are potent against HL-60 cells with the IC50 value ≤5 μM, while some of the compounds were active against few studied Gram-positive bacteria.

Separation via Flotation and Spectrometric Determination of Copper(II) in Environmental Samples using a Newly Synthesized Girard T Derivative

A simple, highly sensitive and selective spectrophotometric procedure was developed for the determination of copper(II) ions. The procedure is based on the reaction at pH 4-7 between the newly synthesized Girard T derivative N-{[(phenylamino)thioxo methyl] hydrazino carbonyl methyl}trimethyl ammonium chloride (PTHAC) and Cu(II) to form an intense green Cu(II):PTHAC (1:1) complex that floats quantitatively with oleic acid (HOL) surfactant. The different analytical factors affecting the flotation and determination processes were examined viz. pH, temperature, concentration of metal, ligand and HOL, etc. The Cu-PTHAC complexes were characterized by elemental analysis, infrared, mass and electronic spectral studies. The formed Cu(II)-PTHAC complex shows a constant and maximum absorbance at 650 nm in the aqueous and scum layers. Beers’ law is obeyed over the concentration rang 0.1-6 mg l-1 with a detection limit of 0.03 mg l-1 and molar absorptivities (at λmax 650 nm) of 0.27×104 and 0.20×105 l mol-1cm-1 in aqueous and surfactant layers, respectively. Sandell’s sensitivity is calculated to be 3.2×10-3 μg cm2 and the relative standard deviation (n=5) is <3.72%. The suggested procedure has been successfully applied to the analysis of copper in different natural waters and ore samples. Moreover, the flotation mechanism is recommended based on some physical and chemical studies of the solid complex isolated from the aqueous and scum layers.

Studies on Coordination Polymers Derived from 2,5-Bis (naphthalen-1-ylcarbamoyl)terephthalicacid

Novel coordination polymers of 2,5-bis(naphthalen-1-ylcarbamoyl)terephthalicacid were prepared by using various metal salts viz. Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) and characterized by physicochemical, thermogravimetric and spectroscopic techniques. Electronic spectral analysis and magnetic measurement studies were taken into account for the geometry of coordination polymers. Polymeric properties have also been carried out. Compounds were evaluated for their antibacterial activity against Gram-positive and Gram-negative bacterial strains. Growth inhibition was compared with the standard drug ciprofloxacin. Antifungal activity was also carried out against different fungal strains. The antifungal drug, ketoconazole was used as a positive control.

Synthesis and characterisation of Cr(III), Fe(III) and Co(III) complexes with biacetyl and bibenzoyl monoxime hydrazone

Complexes of Cr(III), Fe(III) and Co(III) with biacetyl mono oxime phenoxy acetyl hydrazone(BAMPxH), bibenzoyl monoxime phenoxy acetyl hydrazone(BBMPxH) have been isolated and characterized by analytical data, molar conductance, magnetic measurement, electronic spectra and thermo–gravimetric analysis. Cr(III), Fe(III) and Co(III) complexes were found to have octahedral structure. This paper describes the preparation and characterization of transition metal complexes of biacetyl monoxime phenoxy acetyl hydrazone (BAMPxH) and bi benzoyl monoxime phenoxy acetyl hydrazone (BBMPxH). The stereo−chemistry of the coordination compounds has been confirmed on the basis of electronic spectral and magnetic moment studies. Racah's inter−electronic parameter (B), Cubic Ligand field splitting parameter (10Dq) and Nephelauxetic ratio (β), g, λ,h have also been calculated and found that the values are in accordance with the stereo−chemical structure of the coordination compounds. The ligands BAMPxH and BBMPxH are of greater importance since they have ability to chelate metal ion through nitrogen/or oxygen donor centers. Thess ligands can form such type of complexes which are biologically important. Such metal complexes show interesting and important characteristics, especially in areas such as semiconductors, heat resistance materials and gas separators. There has been growing interest for polymeric compounds which are coordinated between ligands and transition metal complexes.

Studies on Some Dioxouranium(VI) Complexes with Dithiocarbamate Ligands

A number of dioxouranium(VI) complexes of some monobasic biden- tate dithiocarbamate(dtc) ligands have been synthesized. Monobasic bidentate dithiocarbamate ligands were prepared by the reaction of 1:1 molar ratio of ethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, 1,3-propanediamine, N,N-dibutyl-tri-methylenediamine, 1,6-hexanediamine with carbondisulphide. Physico-chemical analytical, e.g. elemental analysis, IR Spectral data suggest the formation of (UO 2 L 2 ) type complexes. The molar conductance values obtained for a number of complexes indicate the non-elec- trolytic nature of the complexes. The magnetic and electronic spectral studies of the prepared complexes indicate the presence of the 5f 0 6d 0 7s 0 electronic configuration characteristic of the 6+ oxidation state of uranium.

Spectroscopic, Thermal and Biological Studies of Zn(II), Cd(II) and Hg(II) Complexes Derived from 3-Aminopyridine and Nitrite Ion

Microwave assisted syntheses of Zn(II), Cd(II) and Hg(II) complexes with 3-aminopyridine (3AP) and nitrite (<TEX>$NO_2{^-}$</TEX>) ions have been reported. The metal complexes were characterized by elemental analyses, molar conductance, IR, Far-IR, electronic, NMR (<TEX>$^1H$</TEX>, <TEX>$^{13}C$</TEX>), thermal and electron impact mass spectral studies. The spectroscopic studies reveal the composition, the nature of nitrite ligand in the complexes, electronic transitions, chemical environments of C and H atoms thermal degradation of the complexes. On the basis of characterization data, distorted tetrahedral geometry is suggested for Zn(II), Cd(II) and Hg(II) complexes. The organic ligand (3AP) and their metal complexes were screened against gram negative pathogenic bacteria and fungi in vitro. The results are compared with our previous report J. Korean Chem. Soc. 2013, 57, 341 on 4-aminopyridine and nitrite ion complexes of the same metal ions.

Synthesis and Characterization of Copper Complex of Salicylaldehyde Benzoyl Hydrazone

Copper complex of type [Cu(SBH)2] was synthesized and characterized by different analytical procedure and spectral studies. The complex was insoluble in common organic solvents and it has melting point in between 254-258°C. Infrared spectrum showed the bonding through enolic oxygen and azomethine nitrogen. The electronic spectral studies showed that the Cu(II) is in tetrahedral coordination environment. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9231Journal of Nepal Chemical SocietyVol. 29, 2012Page: 11-17Uploaded date : 12/3/2013

Effect of 1,10-phenanthroline on DNA binding, DNA cleavage, cytotoxic and lactate dehydrogenase inhibition properties of Robson type macrocyclic dicopper(II) complex

DNA targeting macrocyclic dicopper(II) complex, [Cu2L(H2O)2](phen)2(ClO4)2 (L = μ-11,23-dimethyl-3,7,15,19-tetraazatricyclo-[19.3.1.19,13,21] he p t a c o s a-1(24), 2, 7, 9, 11, 13(26), 14, 19, 21(25), 22-decaene-25,26-diol) (2), has been synthesized and characterized. This has been synthesized by reacting a Robson type macrocyclic precursor dicopper(II) complex [Cu2L(H2O)2](ClO4)2 (1) and 1,10-phenanthroline in ethanol. Solution ESR, electronic, and ESI-MS spectral studies suggest that 1,10-phenanthroline replaces coordinated water in 1, giving 2. The influence of the phenanthroline on DNA binding, cleavage, and anticancer properties of 2 have been investigated. Complex 2 displays better DNA binding and cleavage than 1. The dicopper(II) complexes 1 and 2 show cytotoxicity in human cervical HeLa cancer cells, giving IC50 values of 79.41 and 15.82 μM, respectively. Antiproliferative properties of 1 and 2 were confirmed by Trypan Blue exclusive assay and lactate dehydrogenase enzyme level in HeLa cancer cell lysate and content media.

Synthesis and crystal structure of a ternary copper(II) complex of 2,2′-bipyridine and picrate: Molecular docking, reactivity towards DNA and in vitro anticancer activity

A new mononuclear ternary copper(II) complex with mixed ligands of 2,2′-bipyridine (bpy) and picrate (pic), namely [Cu(bpy)(pic)2], has been synthesized and characterized by elemental analysis, molar conductivity measurement, IR and electronic spectral studies, and single-crystal X-ray diffraction. The crystal structure analysis reveals the presence of two crystallographic independent molecules in an asymmetric unit. The copper(II) atoms are in elongated octahedral coordination geometries. A three-dimensional supermolecular network is formed through non-classical C−H⋯O hydrogen bonds. The DNA-binding properties of the copper(II) complex are investigated both theoretically and experimentally, revealing that the copper(II) complex can interact with HS-DNA in the mode of intercalation, and the molecular docking of the copper(II) complex with the self-complementary DNA duplex of sequence d(ACCGACGTCGGT)2 facilitates the binding events. The in vitro anticancer activities suggest that the copper(II) complex is active against the selected tumor cell lines.

Synthesis, spectroscopic (electronic, IR, NMR and ESR) and theoretical studies of transition metal complexes with some unsymmetrical Schiff bases

Two unsymmetrical Schiff bases, glyoxal salicylaldehyde oxalic acid dihydrazone (gsodh) and glyoxal salicylaldehyde malonic acid dihydrazone (gsmdh) and their Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The structures of metal complexes are elucidated on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, electronic, ESR, IR and NMR (1H and 13C) spectral studies. Both ligands show monobasic tetra-dentate behaviour, bonding through CO, two CN and a phenolate group. The electronic spectral studies in solid state indicate a square planar geometry for Ni(II) and Cu(II) complexes and a tetrahedral geometry for Co(II) complexes. However, Co(II) and Cu(II) complexes adopt octahedral geometry in DMSO solution. The ESR spectra of Cu(II) complexes in DMSO solution at 77K predict an elongated tetragonal distorted octahedral geometry around metal ion and presence of unpaired electron in dx2-y2 orbital. Further, the structures of ligands and their Ni(II) complexes have been satisfactorily modelled by calculations based on density functional theory (DFT). The electronic spectra of Ni(II) complexes are also analyzed in depth with the help of time dependent-DFT (TD-DFT). The theoretical analyses of electronic structure and molecular orbitals have demonstrated that the high-energy absorption bands are M→L charge transfer and low energy transitions are d–d transitions.

Characterization and electronic spectral studies of 2-(naphthalen-1-yl)-4,5-diphenyl-1H-imidazole bound Fe2O3 nanoparticles

Multicomponent, one-pot, highly efficient, indium trifluoride (InF3) catalytic synthesis of 2-(naphthalen-1-yl)-4,5-diphenyl-1H-imidazole under solvent-free condition is reported. Characterization of imidazole has been carried out by spectral techniques. The synthesized phosphated imidazole (PI) and phosphated imidazole bound magnetic nanoparticles (PIBMN) were characterized using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and powder X-ray diffraction (XRD). The photophysical characteristics of the synthesized phosphated imidazole and phosphated imidazole bound magnetic nanoparticles were investigated by steady-state absorption and emission spectroscopy as well as time resolved fluorometry. From these experiments, the position of the spectral maxima (λabs, λexc and λemi), and lifetime (τ) of the synthesized phosphated imidazole and phosphated imidazole bound magnetic nanoparticle have been determined.

Modern spectroscopic technique in the characterization of biosensitive macrocyclic Schiff base ligand and its complexes: Inhibitory activity against plantpathogenic fungi

Complexes of the type [M(L)Cl2], where M=Co(II), Ni(II) and Cu(II) have been synthesized with a macrocyclic Schiff base ligand (1,4,5,7,10,11,12,15-octaaza,5,11,16,18-tetraphenyl, 3,4,12,13-tetramethyl cyclo-octadecane) derived from Schiff base (obtained by the condensation of 4-aminoantipyrine and dibenzoyl methane) and ethylenediamine. The ligand was characterized on the basis of elemental analysis, IR, 1H NMR, EI Mass and molecular modeling studies while the complexes were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, electronic and EPR spectral studies. All the complexes are non-electrolyte in nature. The covalency factor (β) and coefficient factor (α) suggest the covalent nature of the complexes. The ligand and its metal complexes have shown antifungal activity with their LD50 values determined by probit analysis against two economically important fungal plant pathogens i.e. Macrophomina phaseolina and Fusarium solani.

Spectroscopic and biological approach in the characterization of a novel 14-membered [N4] macrocyclic ligand and its Palladium(II), Platinum(II), Ruthenium(III) and Iridium(III) complexes

A novel, tetradentate nitrogen donor [N4] macrocyclic ligand, i.e. 3,5,14,16-tetramethyl-2,6,13,17-tetraazatricyclo[12,0,07-12] cosa-1(22),2,5,7,9,11,13,16,18,20-decaene(L), has been synthesized and characterized by elemental analyses, IR, Mass, and 1H NMR spectral studies. Complexes of Pd(II), Pt(II), Ru(III) and Ir(III) have been prepared and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, Mass, electronic spectral and thermal studies. On the basis of molar conductance the complexes may be formulated as [PdL]Cl2, [PtL]Cl2, [Ru(L)Cl2]Cl and [Ir(L)Cl2]Cl. The complexes are insoluble in most common solvents, including water, ethanol, carbon tetrachloride and acetonitrile, but soluble in DMF/DMSO. The value of magnetic moment indicates that all the complexes are diamagnetic except Ru(III) complex which shows magnetic moment corresponding to one unpaired electron. The magnetic moment of Ru(III) complex is 1.73 B.M. at room temperature. The antimicrobial activities of ligand and its complexes have been screened in vitro, as growth inhibiting agents. The antifungal and antibacterial screening were carried out using Food Poison and Disc Diffusion Method against plant pathogenic fungi and bacteria Alternaria porri, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa respectively. The compounds were dissolved in DMSO to get the required solutions. The required medium used for these activities was PDA and nutrient agar.

Synthesis and characterization of heterotrinuclear bis(μ2-chlorido)dicopper (II) mono zinc(II) complexes derived from succinoyldihydrazones

Three new zinc (II)–copper (II) heterometallic trinuclear complexes of the composition [ZnCu2(Ln)(μ2-Cl)2(H2O)6]⋅2H2O (H4Ln=H4L1, H4L2, H4L3) have been synthesized from substituted succinoyldihydrazones (H4Ln) in methanol medium. The composition of the complexes has been established on the basis of data obtained from analytical, mass spectral studies and molecular weight determinations in DMSO. The structure of the ligand H4L2 has been established by X-ray crystallography. The structure of the complexes has been discussed in the light of molar conductance, magnetic moment, electronic, EPR, IR and FT-IR spectral studies. The molar conductance values for the complexes fall in the region 1.2–1.7ohm−1cm2mol−1 in DMSO solution indicating that all of these are non-electrolyte. The magnetic moment values suggest weak M–M interaction in the structural unit of the complexes. The dihydrazone ligand is present in enol form in all of the complexes. Copper centre has tetragonally distorted octahedral stereochemistry. The EPR parameters of the complexes indicate that the copper centre has doublet state as the ground state. The electron transfer reactions of the complexes have been investigated by cyclic voltammetry.

Synthesis, structural and corrosion inhibition properties of some transition metal(II) complexes with o-hydroxyacetophenone-2-thiophenoyl hydrazone

A series of metal complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with o-hydroxyacetophenone-2-thiophenoyl hydrazone (Hhath) have been synthesized. The metal complexes were characterized with the help of elemental analyses, magnetic susceptibility measurements, electronic, IR, NMR and ESR spectral techniques. The structures of Hhath ligand and its Mn(II) complex were determined by single crystal X-ray diffraction studies. Hhath displays E configuration about the >CN– bond. The molecular structure of ligand is stabilized by inter- and intra-molecular H-bonding whereas, [Mn(hath)2] complex is stabilized by π–π and C–H⋯π interactions. In all the complexes, ligand behaves as mono-anionic tridentate and binds to the metal ions via deprotonated phenolate-oxygen, carbonyl-oxygen and azomethine-nitrogen. Magnetic moments and electronic spectral studies suggest an octahedral geometry around metal ion in all the complexes. Frozen solution ESR spectra of Cu(II) complex in DMSO gives axial signal and suggests 2B1g as the ground state. The ligand and its metal complexes showed appreciable corrosion inhibition activity against corrosion of mild steel in 1M HCl solution. The inhibition efficiency of the inhibitors was found to increase with time up to 12h and thereafter almost constant. The metal complexes showed greater inhibition efficiency than the free ligand.