Metal Complexes Of Derivatives Research Articles

New transition metal complexes of enantiomeric benzimidazol derivatives in presence of dinitrogen or phosphorous aromatic donors: Synthesis, characterization and DNA interaction

New transition metal complexes of enantiomeric benzimidazol derivatives in presence of dinitrogen or phosphorous aromatic donors: Synthesis, characterization and DNA interaction

Metal Complex Derivatives of Azole: a Study on Their Synthesis, Characterization, and Antibacterial and Antifungal Activities

Four new zinc complex derivatives of azoles and ligands were synthesized and isolated as white air-stable solids and characterized by elemental analyses, thermogravimetric analysis (TGA), infrared spectroscopy, nuclear magnetic resonance (NMR) and mass spectra. The elemental analysis, theoretical calculations and NMR show that the complexes likely have a 1:1 (M:L) stoichiometry and tetrahedral geometry. To evaluate the biological activity of the complexes and to discuss the role of metal ions and structural properties, the ligands and their metal complexes have been studied. Their antimicrobial activity was determined in vitro by agar-well diffusion and broth microdilution against nine bacterial strains and seven fungal strains with clinical relevance. In vitro assays showed that the complexes exhibited moderate antibacterial and/or antifungal activities. The antimicrobial activity was found to be more active for the metal complexes than the ligands. The metal complexes that contained copper and cobalt, respectively, displayed notable antibacterial and antifungal effects against all the tested bacterial strains. The minimum inhibitory concentration 50 (MIC50) values were in the range 2454-0.7 µg mL-1. Metal complexes were more effective at inhibiting bacteria than fungi. The results could provide a high-potential solution for antimicrobial growth resistance, for both bacteria and fungi.

Simple terpyridine based Cu(II)/Zn(II) complexes for the selective fluorescent detection of H2S in aqueous medium

Simple 4′-phenyl-2,2′:6′,2″-terpyridine derived metal complexes (1.Cu and 1.Zn) are studied for selective detection of H2S, based on metal displacement approach. Probe 1.Cu exhibits turn-on and 1.Zn exhibits turn-off fluorescence detection of H2S both in aqueous buffer and biological medium. In the presence of H2S, fluorescent output signal turned ON or OFF by simply changing the metal from copper to zinc in terpyridine coordination center. The advantages of the probes include a low detection limit (2.2μM for 1.Cu and 31μM for 1.Zn), fluorescent response, good selectivity, high sensitivity and fast response (45–60s) and easy to synthesize the probe. Furthermore, the detection of H2S could be used for the construction of INHIBIT and NAND molecular logic gates based on the optical signal.

DC Electrical Conductivity of Three-Branched Dendritic and Linear Metal Complexes of N-Substituted Imidazole Phenanthroline Derivatives

N-substituted imidazole phenanthroline dendritic metal complexes of 2-(4-(4,5-diphenyl-2,5-1H-imidazol-2-yl)phenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline, N-phenyl substituted phenylene imidazole derivative (TIPIP) and N,N-dimethyl phenylene imidazole derivative (MIPIP), were synthesized and characterized. DC electrical conductivity behavior vs. temperature in the range 300–500 K of the prepared three-branched metal (II) complexes of Co, Ni, Cu, Zn, Cd, and Hg was studied. Of the entire dendritic metal complexes, Cu(II) complexes showed the best electrical conductivity in the range 10−7–10−12 Scm−1; a semiconductor behavior. For comparison, the linear Cu(II) complexes of TIPIP and MIPIP were synthesized and their electrical conductivity behavior was studied. Linear and dendritic Cu(II) complexes showed consistent DC electrical conductivity behavior. N,N-dimethyl substituted phenylene imidazole (MIPIP) Cu(II) dendritic and linear complexes showed the highest electrical conductivity values which reached 10−7 Scm−1 at high temperatures. The synthesized materials were characterized using CHN analyses, FTIR, UV-visible, 1H-NMR, and thermal analyses (TGA, DTA).

A Study on Spectro-Analytical Aspects, DNA - Interaction, Photo-Cleavage, Radical Scavenging, Cytotoxic Activities, Antibacterial and Docking Properties of 3 - (1 - (6 - methoxybenzo [d] thiazol - 2 - ylimino) ethyl) - 6 - methyl - 3H - pyran - 2, 4 - dione and its Metal Complexes.

The focus of the present work is on the design, synthesis, characterization, DNA-interaction, photo-cleavage, radical scavenging, in-vitro cytotoxicity, antimicrobial, docking and kinetic studies of Cu (II), Cd (II), Ce (IV) and Zr (IV) metal complexes of an imine derivative, 3 - (1 - (6 - methoxybenzo [d] thiazol - 2 - ylimino) ethyl) - 6 - methyl - 3H - pyran - 2, 4 - dione. The investigation of metal ligand interactions for the determination of composition of metal complexes, corresponding kinetic studies and antioxidant activity in solution was carried out by spectrophotometric methods. The synthesized metal complexes were characterized by EDX analysis, Mass, IR, (1)H-NMR, (13)C-NMR and UV-Visible spectra. DNA binding studies of metal complexes with Calf thymus (CT) DNA were carried out at room temperature by employing UV-Vis electron absorption, fluorescence emission and viscosity measurement techniques. The results revealed that these complexes interact with DNA through intercalation. The results of in vitro antibacterial studies showed the enhanced activity of chelating agent in metal chelated form and thus inferring scope for further development of new therapeutic drugs. Cell viability experiments indicated that all complexes showed significant dose dependent cytotoxicity in selected cell lines. The molecular modeling and docking studies were carried out with energy minimized structures of metal complexes to identify the receptor to metal interactions.

Metal complexes of 6-pyrazolylpurine derivatives as models for metal-mediated base pairs

6-(3,5-Dimethylpyrazol-1-yl)purine has recently been introduced as an artificial nucleobase for the specific recognition of canonical nucleobases via the formation of a metal-mediated base pair. We report here the synthesis and structural characterization by single crystal X-ray diffraction analysis of a series of metal complexes of the corresponding alkylated model nucleobases 9-methyl-6-(3,5-dimethylpyrazol-1-yl)purine 2 and 9-methyl-6-pyrazol-1-yl-purine 7. The sterically more demanding ligand 2 forms the Cu2+ complexes [Cu(2)(NO3)2] and [Cu(2)Cl2] with a 1:1 stoichiometry of ligand and metal ion. In contrast, ligand 7 forms complexes [Cu(7)2(NO3)](NO3) and [Ag(7)2](ClO4) with a 2:1 stoichiometry. The molecular structures of [Cu(2)(NO3)2] and [Cu(2)Cl2] confirm the previously suggested coordination pattern, i.e. Cu2+ is coordinated via the pyrazole nitrogen atom and the purine N7 position. The fact that different relative orientations of the two ligands in [Cu(7)2(NO3)](NO3) and [Ag(7)2](ClO4) are observed allows the prediction that the corresponding metal-mediated homo base pairs should be stable both in regular antiparallel-stranded and in the rare parallel-stranded double helices.

Cytotoxic effects of palladium complexes containing squaric ligands and sulfosuccinic acid on cancer cell lines

Background: Some metal complex derivatives can have an effective role in cancer treatment. The most common used components are platinum complexes which have numerous side effects, whereas, palladium complexes have shown fewer toxicity rate. Methods: Some of palladium complexes were designed and synthesized for biological evaluation based on the squaric and sulfosuccinic acid ligands. Results: the cytotoxic effects of the synthesized complexes, including 2-iodo squarato palladium (II), 2-iodo sulfosuccinate palladium (II) and 2-amino squarato palladium (II) on different cell lines (Hela, MCF-7, K562, and HUVEC) were examined. To determine the toxicity effect, lactate dehydrogenase (LDH) and trypan blue staining technique were used and the results were compared with cis-platinum. Conclusion: the analysis of binding of new groups to palladium showed higher toxicity of 2-iodo sulfosuccinate palladium on normal cells than control compound. The comparison of compounds indicated that amino group increased the efficacy. Replacement of ion atoms by amino group in 2-amino squarato palladium enhanced the efficacy of the compound on cancer cell lines. 2-amino squarato palladium exerted the maximum effect on PC3 cell line and the minimum effect on Hela with IC50s of 4.33 µM and 18.88µM, respectively. Moreover, 2-amino squarato palladium (II) indicated less toxicity on HUVEC in comparison to cis-platinum.

Energy transfer ultraviolet photodetector with 8-hydroxyquinoline derivative-metal complexes as acceptors**Project supported by the National Natural Science Foundation of China (Grant Nos. 61371046, 61405026, 61474016, and 61421002) and China Postdoctoral Science Foundation (Grant No. 2014M552330).

We choose 8-hydroxyquinoline derivative-metal complexes (Beq, Mgq, and Znq) as the acceptors (A) and 4,4',4”-tri-(2-methylphenyl phenylamino) triphenylaine (m-MTDATA) as the donor (D) respectively to study the existing energy transfer process in the organic ultraviolet (UV) photodetector (PD), which has an important influence on the sensitivity of PDs. The energy transfer process from D to A without exciplex formation is discussed, differing from the working mechanism of previous PDs with Gaq [Zisheng Su, Wenlian Li, Bei Chu, Tianle Li, Jianzhuo Zhu, Guang Zhang, Fei Yan, Xiao Li, Yiren Chen and Chun-Sing Lee 2008 Appl. Phys. Lett. 93 103309)] and REq [J. B. Wang, W. L. Li, B. Chu, L. L. Chen, G. Zhang, Z. S. Su, Y. R. Chen, D. F. Yang, J. Z. Zhu, S. H. Wu, F. Yan, H. H. Liu, C. S. Lee 2010 Org. Electron. 11 1301] used as an A material. Under 365-nm UV irradiation with an intensity of 1.2 mW/cm2, the m-MTDATA:Beq blend device with a weight ratio of 1:1 shows a response of 192 mA/W with a detectivity of 6.5× 1011 Jones, which exceeds those of PDs based on Mgq (146 mA/W) and Znq (182 mA/W) due to better energy level alignment between m-MTDATA/Beq and lower radiative decay. More photophysics processes of the PDs involved are discussed in detail.

Synthesis and Biological Screening of Heterocyclic Ligands-Pyrazole Derivatives Metal Complexes

Synthesis and Biological Screening of Heterocyclic Ligands-Pyrazole Derivatives Metal Complexes

Metallopolymers based on a polyazomethine ligand containing rigid oxadiazole and flexible tetramethyldisiloxane units

ABSTRACTSoluble, easily processable polymer–metal complexes with improved optical and dielectric properties for optoelectronic functional materials were obtained. For this, a new polyazomethine (PAZ2) was prepared by the reaction of a siloxane dialdehyde and bis(formyl‐p‐phenoxymethyl) tetramethyldisiloxane with 2,5‐bis(p‐aminophenyl)‐1,3,4‐oxadiazole, and it was used as a ligand for Cu(II), Co(II), and Zn(II) ions on the basis of the presence of the electron‐donor nitrogen atoms from the azomethine group and oxadiazole ring. The structure of the PAZ2 was determined by spectral [Fourier transform infrared (FTIR) and 1H‐NMR spectroscopy] techniques. The metal complexation was proven by FTIR spectroscopy, and the silicon‐to‐metal ratios in the complexes were established by energy‐dispersive X‐ray fluorescence. The new materials were characterized by gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. The optical properties of PAZ2 and the derived metal complexes were studied by ultraviolet–visible and fluorescence spectroscopies. PAZ2 shows fluorescence emission, and it was significantly enhanced by metal complexation. The emission was enhanced by protonation; this behavior is useful, especially for sensors. The electrical properties were investigated by dielectric spectroscopy at various frequencies and temperatures, and this emphasized the existence of dipolar relaxations. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41631.

Novel dye sensitizers of main chain polymeric metal complexes based on complexes of 2-(2′-pyridyl)benzimidazole derivative with Zn(II), Co(II): synthesis, characterization, and photovoltaic performance for dye-sensitized solar cells

In this paper, four novel D–π–A polymeric metal complex as dye sensitizers for dye-sensitized solar cell, which have Poly(p-phenylenevinylene) or carbazole derivative used as an electron donor, thiophene derivatives used as π-bridge and 2-(2′-pyridyl)benzimidazole derivative metal (Zn, Co) complex used as an electron acceptor (A) were synthesized and characterized. They have been determined and studied by FT-IR, TGA, DSC, GPC, elemental analysis, UV–vis absorption spectroscopy, photoluminescence spectroscopy, cyclic voltammetry, J–V curves and IPCE plots. The results show that four novel polymeric metal complex exhibited good photovoltaic property and thermal stability. The DSSC fabricated by P1, P2, P3 and P4 exhibit good device performance with a power conversion efficiency of up to 2.15, 2.27, 2.30 and 2.41 % (under simulated air mass 1.5 G irradiation) respectively, indicating the polymeric metal complexes are promising in the development of DSSC. .

Synthesis and Antitumor and Surface Activity of Novel Tetrachloro Metallate Complexes of Sulfaquinoxaline with Co(II), Cu(II), or Sn(II) Chlorides

AbstractNew sulfonamide tetrachloro metallate complexes that might possess strong carbonic anhydrase (CA) inhibitory properties were synthesized by the reaction of 4-amino-N-(quinoxalin-2-yl) benzene sulfonamide (sulfaquinoxaline) hydrochloride with different metal chlorides, i.e. CoCl2, CuCl2 or SnCl2. The produced metal complexes of the sulfonamide derivative, containing divalent cations, were characterized by standard procedures. These metal complexes might possess topical antiglaucoma properties which might make them more effective as pharmacological agents. The synthesized complexes exhibited significant cytotoxic activity against colon HCT-116 human cell line. Surface properties of these surfactants were investigated. The surface properties studies included critical micelle concentration (CMC), maximum surface excess (Γmax), minimum surface area (Amin). Free energy of micellization (ΔG°mic) and adsorption (ΔG°ads) were calculated.

ChemInform Abstract: A Review on the Chemistry, Coordination, Structure and Biological Properties of 1‐(Acyl/Aroyl)‐3‐(substituted) Thioureas

AbstractReview: 382 refs.

A silicon-containing polyazomethine and derived metal complexes: synthesis, characterization, and evaluation of the properties

A new dialdehyde-containing silicon was prepared by a reaction of Williamson-type and structurally characterized. By its subsequent condensation with 2,5-bis(p-aminophenyl)-1,3,4-oxadiazole, a multifunctional polyazomethine-containing imine, phenylene, oxadiazole, ether, and carbosilane groups within the chain was prepared. The complexes of this polymer with Co(II), Cu(II), and Zn(II) ions formed on the basis of electron-donor ability of the oxadiazole and azomethine groups were prepared in a one-step approach by mixing the two precursors of polyazomethine (dialdehyde and diamine) with corresponding metal salt. The ligand and metal complexes were characterized by spectral (Fourier transform infrared (FTIR), 1H, and 13C NMR) methods. The thermal, optical, electrochemical, and dielectric properties were studied and the effects of the metal insertion in dependence on its nature over these properties were evaluated. All compounds are soluble in common organic solvents and show low glass transitions due to the flexible ether and Si–C bonds, are fluorescent, mainly due to the oxadiazole ring, are redox active and have high dielectric constant due to the presence of oxadiazole, azomethine metal units.

Synthesis, spectroscopic studies and in vitro antibacterial activity of Ibuprofen and its derived metal complexes

Complexes of Na+, Ag+, Ca2+, Mg2+, Cu2+, Zn2+ and Hg2+ metal ions with the anti-inflammatory drug α-methyl-4-(2-methylpropyl)benzene acetic acid (Ibuprofen) have been synthesized and fully characterized. The IR spectroscopy data showed that Ibuprofen interacts with metal ions through the deprotonated carboxylate group in the bidentate form.Ibuprofen and its Ag+ and Hg2+ complexes showed antibacterial activity against the Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes). The metal complexes resulted significantly more effective than the free Ibuprofen drug.

Synthesis, characterization and preliminary in vitro antibacterial screening activity of metal complex derivatives of 2-[(5-styryl-[1,3,4]thiadiazol-2-ylimino)-methyl]-phenol

Five new metal complex derivatives of 2-[(5-styryl-[1,3,4]thiadiazol-2-ylimino)-methyl]-phenol with the metal ions [Ni(II), Cu(II), Zn(II), Cd(II) and Sn(II)] were prepared in alcoholic medium. The complexes were characterized quantitatively and qualitatively by micro elemental analysis, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, mass spectroscopy, 1H and 13C nuclear magnetic resonance, magnetic susceptibility and conductivity measurements. The spectral study showed that all the complexes obtained as monomeric structures and the central metal moieties are four-coordinated, with tetrahedral geometry, except for the Cu(II) complex, which had square planar geometry. In preliminary in vitro antibacterial screening, all the complexes showed moderate activity against the bacterial strains tested, which was slightly higher than with the ligand.

Alkaloid-Metal Based Anticancer Agents

In order to overcome the significant side effects and the acquired resistance of platinum-based anticancer drugs, great efforts have been devoted to designing new platinum compounds or non-platinum transition metal anticancer complexes with improved pharmacological properties and a broader range of antitumor activity. Among them, the new complexes based on natural alkaloid and their derivatives provide a novel approach to potential (pro-)drugs. This review was mainly focused on the recent progresses of alkaloid-metal based anticancer agents, including metal complexes of natural or synthetic alkaloids, liriodenine, β-carboline, and quinolinoline as anticancer agents, their in vitro anticancer activities and primary action mechanism. Additionally, the future development of hybrid alkaloid and its derivatives metal complexes as anticancer drugs was discussed, which might hold a promise for overcoming multidrug resistance (MDR).

Metal complexes of Schiff base: Preparation, characterization and antibacterial activity

A total of five new metal complex derivatives of 2N-salicylidene-5-(p-nitro phenyl)-1,3,4-thiadiazole, HL with the metal ions Vo(II), Co(II), Rh(III), Pd(II) and Au(III) have been successfully prepared in alcoholic medium. The complexes obtained are characterized quantitatively and qualitatively by using micro elemental analysis, FTIR spectroscopy, UV–Vis spectroscopy, mass spectroscopy, 1H &13C NMR, magnetic susceptibility and conductivity measurements. From the spectral study, all the complexes obtained as monomeric structure and the metals center moieties are four-coordinated with square planar geometry except VO(II) and Co complexes which existed as a square pyramidal and tetrahedral geometry respectively. The preliminary in vitro antibacterial screening activity revealed that complexes 1–5 showed moderate activity against tested bacterial strains and slightly higher compared to the ligand, HL.

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.

Synthesis and cytotoxic activity of metallic complexes of lawsone

In the present study, a series of metallic complexes of the 1,4-naphthoquinone lawsone (2–6) were synthesized and evaluated for potential cytotoxicity in a mouse leukemic macrophagic RAW 264.7 cell line. Cell viability was determined by the MTT assay. Significant growth inhibition was observed for the copper complex (4) with an IC50 value of 2.5μM. This compound was selected for further evaluation of cytotoxic activity on several human cancer cells including HT-29 (human colorectal adenocarcinoma), HepG2 (human hepatocellular carcinoma) and HeLa, (human cervical adenocarcinoma cells). Significant cell viability decrease was also observed in HepG2 cells. The apoptotic potential of this complex was evaluated in these cells. Compound 4 induced apoptosis by a mechanism that involves the activation of caspases 3, 8 and 9 and modulation of apoptotic-related proteins such as Bax, Bad, and p53. These results indicate that metal complexes of lawsone derivatives, in particular compound 4, might be used for the design of new antitumoral agents.