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This study used micro-analyses, (FTIR, UV-Vis) spectra, magnetic, thermogravimetric, X-ray powder diffraction (XRD) patterns, and transmittance electron microscopy (TEM) techniques to characterize three synthesized theophylline (TPH) complexes with ruthenium(III), platinum(IV), and iridium(III) metal ions. The metal ions indicated above were found to align with the TPH drug chelate as a mono-dentate ligand via the deprotonated NH group at the nitrogen atom position N7, as verified by FTIR measurements. Additionally, the complexes conductivity and magnetic susceptibility were examined. The octahedral geometry for the synthesized complexes was proposed by the current data. Except for the iridium(III) complex, which has a non-electrolytic nature due to the presence of a chlorine atom inside the chelation sphere, the molar conductivity of the complexes in DMSO solution was electrolyte in nature. Theophylline complexes with a (metal: ligand) stoichiometry of 1:2 were produced. The TPH complexes have also been tested in vitro against G(+) bacteria (Bacillus subtilis and Staphylococcus Aureus) and G(-) bacteria (Pseudomonas aeruginosa and Escherichia coli) to evaluate their antibacterial efficacy. Human breast and liver cancer cell lines were used as a test for the TPH complexes in vitro anti-cancer properties. [ABSTRACT FROM AUTHOR]

Three new water soluble ternary metal complexes, [Co(metf)(en)2]Cl2(1), [Ni(metf)(en)2]Cl2(2), and [Cu(metf)(en)2]Cl2(3), (Metf = metformin, en = ethylenediamine), were synthesized and characterized, and pharmacodynamic evaluation was reported. From the spectral analysis, octahedral geometry was proposed to all the three metal complexes. The Kinetic parameters have been determined by thermogravimetric data using Coats‐Redfern method. The stability of the complexes was obtained from their molecular orbital structures from which the quantum chemical parameters were calculated using the highest occupied molecular orbital (HOMO)‐lowest unoccupied molecular orbital (LUMO) energies. The DNA binding studies of these complexes were explored by absorption, emission, and viscosity. Groove mode of surface binding of these complexes with DNA was explained by viscosity studies. Nuclease activity exhibited by these complexes on pUC19 DNA was experimented by agarose gel electrophoresis. Discovery Studio 2.1 software was used for docking studies of these complexes into B‐DNA sequence, 5′(D*AP*CP*CP*GP*AP*CP*GP*TP*CP*GP*GP*T)‐3′ retrieved from protein data bank (PDB ID: 423D). The maximum score is seen for complex 1. The antihyperglycemic activity of these complexes was studied in streptozotocin (STZ)‐diabetic rats. The substantial increase in the antihyperglycemic activity of the complexes is seen when compared with pure drug. The maximum antihyperglycemic activity is recorded for complex 1. [ABSTRACT FROM AUTHOR]

Schiff bases and their metal complexes have a number of biological activities such as antidepressant, analgesic, antimicrobial, antiviral, and antitumor. In the present studies, the 1-(( E)-(pentylimino)methyl)naphthalen-2-ol ligand is prepared by the reaction of 2-hydroxynaphthaldehyde with n-amyl amine. The ligand results in CoL, NiL and CuL complexes when reacted with the cobalt acetate, nickel acetate, and copper acetate salts respectively. The complexes along with their ligand are fully characterized by X-ray diffraction studies and biologically screened. The ligand structure reveals that it is a zwitterion species where the iminic nitrogen atom is protonated and the C-O bond shows a high double bond character. The cobalt complex has an octahedral geometry around the metal center and each nitrogen atom is in the trans position to the oxygen donor site. On the other hand, the copper complex shows a centrosymmetric square planar coordination, and in this case, the nitrogen sites are trans to each other. The complexes and the ligand are found to be more potent than the standard drugs used against some microbes in their preliminary biological studies. [ABSTRACT FROM AUTHOR]

μ 2 -Oxido bridged dinuclear vanadium(V) Schiff base complex with the general formula [VO 2 (L)] 2 ·2CH 3 OH was synthesized and characterized. The X-ray results show the complex is dinuclear with two μ-O bridging ions, and the vanadium centers have an octahedral N 2 O 4 coordination sphere. The tridentate Schiff base ligand L coordinated to vanadium(V) center as a monoanion in the basal plane. The basal plane is completed by one of the μ-O bridges. The other μ-O bridge coordinated to vanadium(V) center as apical direction. The two oxido bridged connected the two V v centers together with the V v - O -V v angle of 101.21(6)°, the V O distances of 1.70(6) and 2.31(7) Å and the V⋯V separation of 3.113(5) Å. Finally, the complex was calcinated at 600 °C for 3 h. The FT-IR spectrum of the product shows the formation of the V 2 O 5 particles. [ABSTRACT FROM AUTHOR]

A series of six-coordinated Ni(II) complexes, with the general formula Ni(Xan)L (where Xan = = isoamyldithiocarbonato and L = 2-bromopyridine, 3-bromopyridine, 4-acetylpyridine, 3-hydroxypyridine and 2-methoxypyridine) are synthesized and characterized by the elemental analysis and various physicochemical techniques such as magnetic susceptibility and conductivity measurements, UV-visible and infrared spectral data. Based on the electronic spectra and magnetic susceptibility measurements, an octahedral geometry is proposed for all the complexes. IR spectral data show that in all these complexes substituted pyridines coordinate to the metal ion through nitrogen atoms occupying the fifth and sixth axial positions, whereas O-alkyldithiocarbonate acts as a monoanion bidentate ligand and occupies the planar positions of octahedral structures. The structure of the adduct with 3-bromopyridine is elucidated by the single crystal X-ray diffraction method. The complex crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.5855(4) Å, b = 9.4984(6) Å, c = 12.4518(8) Å, α = 87.944(5)°, β = 78.843(5)°, γ = 77.794(5)°. The crystal structure of the molecule is stabilized by intermolecular C-H...S and C-H...π interactions. [ABSTRACT FROM AUTHOR]

Abstract: Two copper(II) complexes, [Cu(L)N3]n (1) and [Cu(HL)2](I3)ClO4 (2), where HL = 2-pyridylaldehydesemicarbazone, have been prepared and characterized by elemental analysis, IR and UV–Vis spectroscopy and single crystal X-ray diffraction studies. Complex 1 crystallizes in monoclinic space group P21/a, whereas, complex 2 crystallizes in triclinic space group P-1. Complex 1 is a stair-like coordination polymer with square pyramidal geometry of copper(II), whereas, complex 2 is a mononuclear cationic bis-ligand complex of octahedral copper(II). Lower coordination ability of tri-iodide or perchlorate compared to azide may be related with variations of the structures of the complexes. [Copyright &y& Elsevier]

Octahedral magnetite (FeO) nanoparticles (NPs) with dimensions ranging from 20 to 110 nm are prepared via the decomposition of iron oleate complex in the presence of cetyltrimethylammonium bromide (CTAB) and various organic solvents. It is shown that the addition of an optimal amount of CTAB prompts the growth of equi-dimensional octahedral NPs with dominant {111} facets. Moreover, it is shown that the size of the octahedral NPs can be controlled by adjusting the relative amounts of oleic acid and CTAB and choosing an appropriate high-boiling point organic solvent. The X-ray diffraction analysis results reveal that the compositions of the as-synthesized NPs are solvent-dependent and contain different amounts of iron metal, wüstite and magnetite phases. The as-synthesized NPs are oxidized to pure magnetite via an air treatment and the room-temperature magnetic properties of the resulting products are then characterized by means of a superconducting quantum interference device. The results indicate that the superparamagnetic limit for the current magnetite NPs is equal to approximately 33.3 nm at a temperature of 300 K. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A new monoclinic Cu(II) salt complex (CHN) [Cu(2,6-dipico)]·6HO, (2,6-dipico=pyridine-2,6-dicarboxylic acid) is synthesized and characterised by CHN analyses, IR, UV-Vis, magnetic susceptibility measurements, and single crystal X-ray crystallography. The structure contains two pyridine-2,6-dicarboxylate species as tridentate ligands with protonated aniline acting as a counter cation and six uncoordinated water molecules. The complex crystallizes in the monoclinic space group C2/c with unit cell parameters a = 20.9393(4) Å, b = 7.94330(10) Å, c = 19.9093(4) Å, V(Å) = 2932.32(9), Z = 4. Crystal packing is stabilized by N-H...O, O-H...O intermolecular hydrogen bonds and weak π...π interactions. The water molecules are trapped by a cooperative association of coordination interactions forming water clusters as well as by a hydrogen bond to the Cu (II) complex. [ABSTRACT FROM AUTHOR]

Abstract: A series of octahedral and square-planar Ni(II) complexes have been synthesized from two different types of hydrazone ligands. The isolated complexes have been characterized by means of analytical and spectroscopic techniques. The structures of two of the complexes have been determined by single crystal X-ray diffraction study. The binding modes of the complexes with DNA and their ability to bind DNA have been investigated by UV–Vis absorption titration, ethidium bromide fluorescence displacement experiments, and viscometry measurements and cyclic voltammetry studies. The experimental results show that the mode of binding of the complexes to DNA is combination of different mode of interaction. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis of macrocyclic ligands and their metal complexes is a fast developing area of research in bioinorganic and inorganic chemistry as witnessed by biologically important systems. A new series of divalent copper, nickel, iron and cobalt complexes has been prepared templately with 2,2-dihydroxyindane-1,3-dione and isomeric diaminopyridines and efficacy of these complexes is studied against Alternaria alternata and Fusarium oxysporum. The complexes have been characterized by the aid of elemental analyses, molar conductance, electronic spectra, ESR, magnetic measurements and IR spectral data has been collected. The complexes are proposed to be distorted octahedral. The value of molar conductance (11–13Ω−1 cm2 mol−1) indicates them to be non-electrolytes. The fungicidal properties of these complexes has been compared with the standard indofil M-45 and bavistin. Some of the complexes have been found to be anti-fungal in nature. [Copyright &y& Elsevier]

Abstract: 1-Alkyl-2-{(o-thioalkyl)phenylazo}imidazole (SRaaiNR/, 1) reacts with Co(ClO4)2·6H2O to form [Co(SRaaiNR/)2](ClO4)2 (2). The single crystal X-ray structure of one of the complexes of 2 shows a tridentate chelation N(imidazole), N(azo), S(thioether) system. In the structure one of ClO4 − anions shows disorder and forms an (imidazole)C–H···O(ClO3) interaction leading to a 1-D chain. Co(OAc)2.4H2O and SRaaiNR/ react in the presence of NH4SCN (1:1:2 mole ratio) in methanol and the complex [Co(SRaaiNR/)2(SCN)2] (3) has been separated. The single crystal X-ray structure determination has established the structure of the complexes in which the ligand SRaaiNR/ acts in a bidentate N(imidazole), N(azo) chelation mode. A cyclic voltammogram shows a Co(III)/Co(II) oxidative response at 0.6–0.8V and azo reductions. DFT computation using optimized geometry support the electronic spectral and redox properties of the complexes. [Copyright &y& Elsevier]

Abstract: Two different sets of Schiff base ligands, set-1 (HL1 , HL2 ) and set-2 (H2L3 , H2L4 ) which have been prepared by mixing 1,3-diaminopropane and aldehydes (3-methoxy-2-hydroxybenzaldehyde or 3-ethoxy-2-hydroxybenzaldehyde) in 1:1 and 1:2 ratios, respectively, are employed for the synthesis of complexes with cobalt perchlorate. The octahedral cobalt(III) complexes of general formula [Co(L)2]ClO4 (L= L1 for complex 1, L2 for complex 1a) are obtained from the mono-condensed ligands, whereas the di-condensed ligand H2L4 results in the formation of a unique type of mixed-ligand complex [Co(L2)(L4)]ClO4 (2) where the respective di- and mono-condensed Schiff bases simultaneously coordinate to the metal center. The complexes are completely characterized by elemental analyses, IR, UV–vis spectroscopy and cyclic voltammetric studies. The structures of 1 and 2 are unequivocally established by single crystal X-ray diffraction analysis. The behavior of the Schiff base ligands during the reactions is directed by the template effect of CoIII ion modulated by the perchlorate anion present in the medium. [Copyright &y& Elsevier]