ESR Spectral Studies Research Articles

Synthesis, Characterization, 3D Modeling, Biological Activities of Some Metal Complexes of Novel Sulpha Drug Schiff Base Ligand and Its Nano Cu Complex

Novel solid Co(II), Ni(II), Cu(II) and Zn(II) complexes of sulpha drug Schiff base ligand (HL) derived from condensation of sulphaquinoxaline and naphthaldehyde namely, 2-{4-[(2-hydroxynaphthalen-1-yl) methyleneamino] benzenesulfonamido} quinoxalin (HNMABSQ), in addition new mixed ligand complexes with 8-hydroxyquinoline (8-HQ) or 1,10 Phenanthroline (1,10 Phen) with HL and these metal (II) ions were synthesized. The structure of complexes were proposed in light of analytical, IR, 1H-NMR, Mass, UV-Vis, ESR spectral data, magnetic and thermal studies. The molar conductance data reveal that all the metal chelates were non-electrolytes. The kinetic and thermodynamic parameters for decomposition steps in Co(II), Ni(II) and Cu(II) complexes thermo grams were calculated. On the basis of these studies, most complexes have octahedral geometry but few can attain the square planar arrangement. 3D modeling of the ligand and its metal complexes were studied by PM3 method, also the heat of formations, HOMO, LUMO and dipole moments were calculated to confirm the geometry of the ligand and its complexes. Schiff base ligand and its metal complexes were tested for antimicrobial activities. Nano-Cu- Schiff base complex was synthesized and characterized by scanning electron microscopy (SEM) and its biological activities were studied. The Cu nano complex had higher antibacterial and antifungal activity than the ligand and its metal complexes. Also, all tested compounds inhibited the growth of the liver cancer cell.

Synthesis, Characterization, Antimicrobial, DNA Binding and Cleavage Studies of Mixed Ligand Cu(II), Co(II) Complexes

The mixed ligand complexes MLA of Cu(II) and Co(II) with Schiff base derived from 4-amino antipyrine and 5-NO(2) salicylaldehyde (2,3 -dimethyl-1-phenyl-4-(2-hydroxy-5-nitro benzylideneamino)-pyrazol-5-one) as ONO donor (L) and A = 2,2 bipyridine (bpy),1,10 phenonthroline (1,10 phen) as N, N donor ligands have been prepared, owing to their biological and other applications. The structural features have arrived from their elemental analyses, magnetic susceptibility, molar conductance, Mass, IR, UV-VIS, powdered XRD and ESR spectral studies, that established MLA type of composition for the metal complexes. The electronic absorption spectral data of the complexes suggest an octahedral geometry around the central metal ion. The interaction of the complexes with Calf Thymus (CT) DNA has been studied using absorption spectra, viscosity measurements and fluorescence spectra. The binding constants (K(b)) of the complexes were determined as 2.1 × 10(6) M(-1) for complex 1, 2.5x10(6)M(-1) for complex 2, 1.16 × 10(6) M(-1) for complex 3,1.25x10(6)M(-1) for complex 4, DNA cleavage experiments performed on pBR-322 plasmids using metal complexes in the presence of H(2)O(2) showed that all the complexes afford a pronounced DNA cleavage. Molecular modelling studies were also performed to confirm the geometries of the complexes. The ligand and their metal complexes were screened for their antimicrobial activity against bacteria. The results showed that the metal complexes are biologically active.

Synthesis, structural characterization, in vitro antimicrobial and anticancer activity studies of ternary metal complexes containing glycine amino acid and the anti-inflammatory drug lornoxicam

Mixed ligand complexes were synthesized using lornoxicam (LOR) as the primary ligand and glycine amino acid (HGly) as the secondary ligand. They were characterized by FT-IR, UV–Vis, mass, 1H NMR, ESR spectral studies, TG–DTG, X-ray powder diffraction and physical analytical studies. From the molar conductance, magnetic moment and electronic spectral data of the synthesized complexes, general formulae of [M(LOR)2(Gly)]·Xn·yH2O where M=Cr(III) (X=Cl, n=2, y=3), Mn(II) (X=Cl, n=1, y=1), Co(II) (X=BF4, n=1, y=0), Ni(II) (X=Cl, n=1, y=0), Cu(II) (X=BF4, n=1, y=2) and Zn(II) (X=BF4, n=1, y=2) and (M=Fe(II) (X=BF4, n=1, y=1) and Fe(III) (X=Cl, n=2, y=1) with an octahedral structure were proposed. Thermal analyses show that the complexes lose water molecules of hydration initially and subsequently expel anionic parts and organic ligands in continuous steps. The kinetic parameters namely E, ΔH∗, ΔS∗ and ΔG∗ illustrate the spontaneous association of the metal and ligands in the formation of the complexes. The antimicrobial efficiency of the LOR and HGly ligands and the ternary complexes were examined by in vitro method against various pathogenic bacterial and fungal strains. The metal complexes were found to possess efficient antimicrobial properties compared to lornoxicam and most of these complexes could turn out to be excellent models for the design of effective antibiotic drug substances. Also, the two ligands, in comparison to ternary metal complexes are screened for their anticancer activity against breastic cancer cell line. The results showed that the metal complexes be more active than the parent LOR and glycine free ligands except Cr(III) ternary complex which was found to be inactive.

Oxygen-initiated stereoselective thermal isomerisation of a cyclobutane derivative in the solid state.

Solid-state [2+2] photochemical cycloaddition reactions have been extensively studied after the classical work of Schmidt in the 1960s. Of these, trans-1,2-bis(4'-pyridyl)ethylene (bpe) is one of the well-studied alkenes to synthesize tetrakis(4-pyridyl)cyclobutane (tpcb). However, almost all the solid-state [2+2] cycloaddition reactions of bpe yielded, almost exclusively, one of the four possible isomers, namely, the rctt-tpcb (r=regio c=cis and t=trans). Here we describe a stereoselective synthesis of the tetrahedrally disposed rtct-tpcb by the solid-state thermal isomerization of the rctt-isomer in atmospheric air. We propose that this isomerization occurs through a topochemical unimolecular mechanism by a radical chain pathway, initiated by molecular oxygen. This is supported by the nature of products formed in air and nitrogen, detection of a radical in ESR spectral studies, ESI-MS crossover experiments, VT PXRD studies along with QM, MD and docking calculations. The formation of a unique isomer by thermal isomerization may be a general phenomenon to quantitatively synthesize other useful stereoisomers from the existing isomers of cyclobutane derivatives.

The influence of valence states of tungsten ions on PbO–Y2O3–P2O5 glass network

Lead yttrium phosphate glasses mixed with different concentrations of WO3 (ranging from 0 to 5.0mol%) were synthesized. Differential thermal analysis (DTA), optical absorption, ESR and IR spectral studies have been carried out. The results of DTA have indicated that there is a gradual decrease in the resistance of the glass against devitrification with increase in the concentration of WO3 up to 3.0mol%. The optical absorption spectra of these glasses exhibited a relatively broad band peaking at about 850nm identified due to dxy−dx2–y2 transition of W5+ ions; this band is observed to be more intense in the spectrum of glass containing 3.0mol% of WO3. The ESR spectra of these glasses recorded at room temperature exhibited an asymmetric signal at g⊥∼1.71 and g||∼1.62. The intensity of the signal is observed to be maximal for the spectrum of the glass PYPW3. The optical absorption and ESR spectral studies have indicated that there is a maximum reduction of tungsten ions from W6+ state to W5+ state in the glass containing 3.0mol% of WO3. The IR spectral studies have indicated that there is an increasing degree of disorder in the glass network with increase in the concentration of WO3 up to 3.0mol%.

Computational studies of the first order kinetic reactions for mononuclear copper(II) complexes having a hard–soft NS donor ligand

The chelation behaviour of 4-((E)-2-(1-(thiophen-2-yl)ethylidene)hydrazinyl)-1-(4-methoxyphenyl)-1H-pyrrole-3-carbonitrile (HL) towards Cu(II) ions has been investigated. These Cu(II) complexes are characterized by elemental analyses, molar-solid conductance, ESR, FTIR and electronic spectral studies. Also, the kinetic and thermodynamic parameters (Ea, A, ΔH, ΔS, ΔG) for all thermal decomposition steps have been evaluated using Coats–Redfern and Horowitz–Metzger methods. Furthermore, antimicrobial activity of the ligand and its complexes were studied against Gram-negative bacteria: Escherichia coli, Gram-positive Bacillus cereus, Bacillus subtilis and pathogenic fungi Pseudomonas aeruginosa by using minimum inhibitory concentrations (MICs) method.

Spectral characterization, electrochemical and anticancer studies on some metal(II) complexes containing tridentate quinoxaline Schiff base

Co(II), Ni(II), Cu(II) and Zn(II) complexes of a tridentate ONO donor Schiff base ligand derived from 3-(2-aminoethylamino)quinoxalin-2(1H)-one were synthesized. The ligand and its metal complexes were characterized using elemental analysis, molar conductance, IR, 1H NMR, mass, magnetic susceptibility, electronic spectra and ESR spectral studies. Electrochemical behavior of the synthesized compounds was studied using cyclic voltammetry. The grain size of the synthesized compounds was determined by powder XRD. The Schiff base and its complexes have been screened for their antimicrobial activities against the bacterial species E. coli, K. pneumoniae, P. aeruginosa and S. aureus; fungal species include, A. niger, and C. albicans by disc diffusion method. The results show that the complexes have higher activity than the free ligand. The interaction of the complexes with calf thymus DNA (CT DNA) has been investigated by electronic absorption method. Furthermore, the DNA cleavage activity of the complexes was studied using agarose gel electrophoresis. In vitro anticancer studies of the ligand and its complexes using MTT assay was also done.

Mixed Ligand Copper (II) Complex with Isoniazid and Pyrazinamide

The fact that the pharmacological action of certain drugs was due to the formation of chelates with essential or trace metal ions of biological significance prompted many research workers all over the world to investigate the structural features of the metal chelates of drug substances both in solid state and in solution. So it was considered interesting and useful to study the metal complexes of drugs using various physicochemical methods. It is proposed to study the metal binding characteristics of some selected pharmaceuticals mentioned below. Isoniazid, a common antituberculosis drug, was shown to form complexes with metal ions like, Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ and Zn 2+ . (1) . Isoniazid was shown to form both 1:1 and 1:2 complexes with copper, binding through oxygen and amino nitrogen. (2-3) Pyrazinamide, another antituberculosis drug was reported to form metal complexes of the type MX2, 4L where M= Co(II), Ni(II), Cu(II) and X = Cl 1 , Br  , I  . Besides thermal and spectral studies of these complexes, ESR spectral study was also made for the copper complex. (4) Nickel was also shown to form neutral

Metal (II) Complexes Derived from Naphthofuran-2-carbohydrazide and Diacetylmonoxime Schiff Base: Synthesis, Spectroscopic, Electrochemical, and Biological Investigation

A new Schiff base and a new series of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) complexes were synthesized by the condensation of naphthofuran-2-carbohydrazide and diacetylmonoxime. Metal complexes of the Schiff base were prepared from their chloride salts of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) in ethanol. The ligand along with its metal complexes have been characterized on the basis of analytical data, IR, electronic, mass, 1HNMR, ESR spectral data, thermal studies, magnetic susceptibility, and molar conductance measurements. The nonelectrolytic behaviour of the complexes was assessed from the measured low conductance data. The elemental analysis of the complexes confirm the stoichiometry of the type CuL2Cl2 and MLCl2 where M = Ni(II), Co(II), Cd(II), and Hg(II) and L = Schiff base. The redox property of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In the light of these results, Co(II), Ni(II), and Cu(II) complexes are assigned octahedral geometry, Cd(II), and Hg(II) complexes tetrahedral geometry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleaving capacity of all the complexes was analysed by agarose gel electrophoresis method.

Coordination modes of bidentate lornoxicam drug with some transition metal ions. Synthesis, characterization and in vitro antimicrobial and antibreastic cancer activity studies

The NSAID lornoxicam (LOR) drug was used for complex formation reactions with different metal salts like Cr(III), Mn(II), Fe(III) and Ni(II) chlorides and Fe(II), Co(II), Cu(II) and Zn(II) borates. Mononuclear complexes of these metals are obtained that coordinated to NO sites of LOR ligand molecule. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, IR, UV–Vis, 1H NMR, mass, electronic spectra, magnetic susceptibility and ESR spectral studies, conductivity measurements, thermogravimetric analyses (TG–DTG) and further confirmed by X-ray powder diffraction. The activation thermodynamic parameters are calculated using Coats–Redfern and Horowitz–Metzger methods. The data show that the complexes have composition of ML2 type except for Fe(II) where the type is [ML3]. The electronic absorption spectral data of the complexes suggest an octahedral geometry around the central metal ion for all the complexes. The antimicrobial data reveals that LOR ligand in solution show inhibition capacity less or sometimes more than the corresponding complexes against all the species under study. In order to establish their future potential in biomedical applications, anticancer evaluation studies against standard breast cancer cell lines (MCF7) was performed using different concentrations. The obtained results indicate high inhibition activity for Cr(III), Fe(II) and Cu(II) complexes against breast cancer cell line (MCF7) and recommends them for testing as antitumor agents.

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, 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.

Antimicrobial, DNA cleavage, and antioxidant properties of new series of metal(II) complexes derived from naphthofuran-2-carbohydrazide Schiff base: synthesis and physico-chemical studies

Metal complexes of the type [NiL2Cl2]·H2O and ML2Cl2 [M = Co(II), Cu(II), Cd(II), Zn(II), and Hg(II)] where L = Schiff base, derived from condensation of naphthofuran-2-carbohydrazide and 2-chloro-3-formylquinoline have been synthesized. The chelation of the complexes have been inferred through elemental analyses, IR, electronic mass, 1H NMR, ESR spectral data, magnetic and thermal studies. The measured low molar conductance values in DMF indicate the complexes to be non-electrolytic in nature. The cyclic voltammetric investigation suggested that, the Cu(II) complex is of single electron transfer quasi-reversible nature. The free ligand and its complexes have been evaluated for their in vitro antibacterial and antifungal activities by minimum inhibitory concentration method. The influence of DNA cleavage on all the complexes was analyzed by agarose gel electrophoresis method. The free ligand with its complexes has been studied for their antioxidant activity by DPPH method. The results of bioassay revealed that, the metal complexes are active than the free ligand and their biological activity increases on complexation.

Influence of Ga3+ ions on spectroscopic and dielectric features of multi component lithium lead boro bismuth silicate glasses doped with manganese ions

Multi-component glasses of the chemical composition 19.5Li2O–20PbO–20B2O3–30SiO–(10−x)Bi2O3–0.5MnO:xGa2O3 with 0≤x≤5.0 have been synthesized. Spectroscopic (optical absorption, IR, Raman and ESR) and dielectric properties were investigated. Optical absorption and ESR spectral studies have indicated that managanese ions do exist in Mn3+ state in addition to Mn2+ state in the samples containing low concentration of Ga2O3. The IR and Raman studies indicated increasing degree of disorder in the glass network with the concentration of Ga2O3 up to 3.0mol%. The dielectric constant, loss and ac conductivity are observed to increase with the concentration of Ga2O3 up to 3.0mol%. The quantitative analysis of the results of dielectric properties has indicated an increase in the insulating strength of the glasses as the concentration of Ga2O3 is raised beyond 3.0mol%. This has been attributed to adaption of gallium ions from octahedral to tetrahedral coordination.

Synthesis, physico-chemical investigations and biological screening of metal (II) complexes with Schiff base derived from naphthofuran-2-carbohydrazide and citral

A series of Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and Hg(II) complexes of the type CuLCl2. 2H2O and ML2Cl2 [M=Co(II), Ni(II), Cd(II), Zn(II) and Hg(II)], respectively, where L=Schiff’s base derived from condensation of citral and naphthofuran-2-carbohydrazide have been synthesized. The proposed structures of the obtained complexes have been established from elemental analyses, IR, Electronic, Mass, 1H NMR, ESR spectral data, magnetic and thermal studies. From the above spectral studies it is concluded that the ligand acts as a bidentate coordinating through azomethine nitrogen and amide oxygen. The measured low molar conductance values in DMF indicate that the complexes are non-electrolytic in nature. The electron transfer mechanism of the Cu(II) complex is investigated by the aid of cyclic voltammetry. The free ligand and its metal complexes have been screened for their antioxidant activity by the DPPH method and in vitro antibacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa) and antifungal (Aspergillus niger, Aspergillus flavus, Cladosporium oxysporum and Candida albicans) activities by the minimum inhibitory concentration (MIC) method. The DNA cleavage studies of all the complexes were studied by agarose gel electrophoresis method. The results indicate that the biological activity increases on complexation.

Transition metal complexes of s-triazine derivative: new class of anticonvulsant, anti-inflammatory, and neuroprotective agents

A new series of transition metal complexes of 2,4-bis(indolin-3-one-2-ylimino)-6-phenyl-1,3,5-triazine) (BIPTZ) have been synthesized. The structural features of BIPTZ and metal(II) complexes were investigated using elemental analyses, magnetic susceptibility, molar conductance, mass, IR, UV–Vis, 1H NMR, 13C NMR, CV, and ESR spectral studies. Electronic absorption spectra and magnetic susceptibility measurements of the complexes predict their geometry. The redox behavior of the copper(II) complexes has been studied by cyclic voltammetry. All the synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence spectrum. The Schiff base and its metal complexes were screened for anticonvulsant and anti-inflammatory activities in vivo. The metal(II) complexes are potent agents in treating neurochemical and behavioral abnormalities seen in Parkinson’s diseased (PD) mice than free ligand.

Dielectric and Spectroscopic properties of CuO doped multi-component Li2O[sbnd]PbO[sbnd]B2O3[sbnd]SiO2[sbnd]Bi2O3[sbnd]Al2O3 glass system

Multi-component silicate glasses of the chemical composition 19.4Li2O20PbO20B2O330SiO2 (10−x) Bi2O30.6 CuO: x Al2O3 with x ranging from 0 to 5mol% have been synthesized.A variety of spectroscopic (optical absorption, IR, Raman and ESR) and dielectric properties (over a range of frequency and temperature) of these glasses have been investigated as a function of Al2O3 concentration. The results of optical absorption and ESR spectral studies have indicated that a part of copper ions do exist in Cu+ state in addition to Cu2+ state especially in the samples containing low concentration of Al2O3. The IR and Raman spectral studies have revealed that there is a decreasing degree of disorder in the glass network with increase in the concentration of Al2O3 upto 3.0mol%. The values of dielectric parameters viz., dielectric constant, loss and ac conductivity at any frequency and temperature are observed to decrease as the concentration of Al2O3 is increased up to 3.0mol%. Such changes have been attributed to increase of redox ratio or increasing proportions of Cu+ ions that take part in the glass network with CuO4 structural units The quantitative analysis of the results of ac conductivity and dielectric properties have indicated a decrease in the insulating character of the glasses when the concentration of Al2O3 is raised beyond 3.0mol% in the glass network. This has been attributed to adaption of aluminium ions from tetrahedral co-ordination to octahedral co-ordination and also due to declustering influence of copper ions by aluminium ions in the glass network.

Spectroscopic and antimicrobial studies of macrocyclic metal complexes derived from 1,8-diaminonaphthalene and dimedone

A new series of macrocyclic metal complexes have been synthesized and characterized by the template condensation reaction of 1,8-diaminonaphthalene and dimedone in presence of divalent transition metals, resulting into the formation of the macrocyclic complexes of the type: [M(C36H36N4)X2]; where M = Co(II), Ni(II), Cu(II), Zn(II) and X = Cl−, NO3−, CH3COO−. The synthesized macrocyclic complexes have been characterized with the aid of elemental analysis, conductance measurements, magnetic susceptibility measurements, electronic, infrared, NMR, Mass and ESR spectral studies. The complexes were also investigated for their fluorescence activity. Electronic spectra along with magnetic moments suggest the six coordinated octahedral geometry for all these complexes. The low value of molar conductance indicates them to be non-electrolyte. The in vitro antimicrobial activities of these macrocyclic complexes have also been investigated against some bacterial strains and yeast. Further minimum inhibitory concentration shown by these complexes against these pathogens was compared with MIC shown by standard antibiotic and standard antifungal drug.

Studies on DNA binding behavior of biologically active Cu(II) complexes of Schiff bases containing acyl pyrazolones and 2-ethanolamine

Pyrazolone derivatives (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one [PMP-EA] (1), (Z)-1-(3-chlorophenyl)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1H-pyrazol-5(4H)-one [MCPMP-EA] (2), and (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-p-tolyl-1H-pyrazol-5(4H)-one [PTPMP-EA] (3) have been synthesized and characterized. The molecular geometry of 2 has been determined by single-crystal X-ray study. These ligands exist in amine-one tautomeric form in the solid state. Three copper(II) complexes, [Cu(PMP-EA)(H2O)2] (4), [Cu(MCPMP-EA)(H2O)2] (5), and [Cu(PTPMP-EA)(H2O)2] (6), respectively, have been synthesized using these ligands and characterized by microanalytical data, molar conductivity, IR, UV–Visible, FAB-Mass, magnetic measurement, TG-DTA studies, and ESR spectral studies; Cu(II) is five-coordinated with [ML(H2O)2] composition. The interaction of the complexes with CT-DNA (calfthymus) was investigated using different methods. The results suggest that the copper complexes bind to DNA via intercalation and can quench the fluorescence intensity of EB bound to DNA.

The Spectroscopic Properties of Mo5+ in ZnO-ZnF2-B2O3 Glasses

The system of glass samples ZnO-ZnF2-B2O3 containing different concentrations of MoO3 (ranging from 1.0-7.0 mol%) were prepared. The glasses were characterized by optical absorption, ESR, FTIR and Raman spectral studies. The analyses of the results of the optical absorption and ESR studies indicated that the molybdenum ions coexisted in Mo5+ state with Mo6+ state in these glasses, whereas the results of the FTIR and Raman spectral studies indicated that there was an increasing degree of disorder in the glass network with increase in the concentration of MoO3.