Synthesis,Spectroscopic Characterization,and Antifungal Activity of Some Mixed Ligand Complexes of Zn(II), Cd(II), and Hg(II)

A series of new mixed ligand complexes of Zn(II), Cd(II), and Hg(II) with citronellal thiosemicarbazone [3,7-dimethyl-6-octene-1-a1 thiosemicarbazone (LH)] and N-phthaloyl amino acids (AH) have been synthesized by the reaction of metal(II) chloride with ligands citronellal thiosemicarbazone (DOTSC) and N-phthaloyl glycine [1,3-dihydro-1,3-dioxo-2H-isoindole-2-acetic acid (A₁H)] or N-phthaloyl alanine [1,3-dihydro-1,3-dioxo-α(methyl)-2H-isoindole-2-acetic acid (A₂H)] in 1:1:1 molar ratio in dry refluxing ethanol. All the complexes have been characterized by elemental analyses, molar conductance measurement, molecular weight measurement, IR, and multinuclear NMR (¹H and ¹³C{¹H}) spectral studies. IR, ¹H, and ¹³C{¹H} NMR spectral studies suggest the involvement of azomethine-N, thiol-S atoms of the thiosemicarbazone moiety and both carboxylate-O of N-phthaloyl amino acid moiety in coordination with central metal(II) ion, and four coordinated geometries have been assigned to these complexes. The free ligands and metal complexes have been screened for their antifungal activity against two fungal strains, Fusarium moniliformae and Macrophomina phaseolina, using the the radial growth method. The results of antifungal activity show that metal complexes show enhanced higher activity than the free ligands.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Preparation and Spectroscopic Characterization of Two Manganese(II)semiquinone Complexes

Summary. The complexes [CTA][Mn(II)(SQ)₃] were isolated in the solid state and purified. SQ is the o-semiquinone of L-dopa or dopamine and CTA is the cetyltrimethylammonium cation. These complexes were characterized by Raman, infrared, EPR and thermogravimetry (TG) techniques. The EPR spectra of the solids presented an intense signal characteristic of the o-semiquinone radical anion with g=2.0062 and g=2.0063 for L-dopa and dopamine, respectively. Six characteristic lines around the organic radical signal confirm the presence of the Mn²⁺ ion. The most intense Raman bands were observed at for dopamine and at 1356 cm^–1 for L-dopa and assigned to a C–O stretching with major C₁–C₂ character. The absence of an intense Raman band at ca. , characterizes the ligands as an o-semiquinone radical anion. Broad bands in the region can be assigned to deformations associated with the five-member ring chelate including the manganese ion, the oxygens, and the C₁–C₂ bonds. The more intense IR bands for the dopamine and the L-dopa-derived ligands at are assigned to CO. Mass loss mechanisms for the two complexes, based on the TG results, were proposed and confirm the formula proposed.     

Thermotropic Mesomorphism in Some Cu(II) and Pd(II) Metallorganic Complexes

The synthesis and liquid crystal properties of some bis(N-p-(n-alkoxy)phenyl, p-(n-alkoxy)salicylaldiminato)copper(II), of a homologous series of bis(N-p-(n-alkanoyloxy)phenyl, p-(n-alkanoyloxy)salicylaldiminato)copper(II), and of some corresponding palladium(II) complexes are reported. All of the compounds examined exhibit enantiotropic smectic mesomorphism, predominantly of the C type. Palladium(II) complexes are mesomorphic up to higher temperatures than the copper(II) homologues.     

Schiff碱Cu(II)配合物的结构、光谱及电化学性质

为了探讨配合物结构对性质的影响,合成了两个Schiff碱的铜配合物{[Cu(II) (L1)]ClO_4(1)和[Cu(II)(L2)-(H_2O)_2](BF_4)_2(2)},并用红外、质谱和元素分 析对它们进行了表征,用X射线衍射方法测定了它们的昌体结构。实验结果表明： 配合物1和2均属三斜晶系,P1空间群。1的晶胞参数为a = 1.1147(6)nm, b = 1. 1481(7)nm, c = 0.770(3)nm; α = 98.81(4) °,β=106.94(4)°γ= 66.49(4)° ;V=0.8715(8)nm~3,Z=2,R=0.044.2的晶胞参数为a=1.0819(4)nm, b = 1.4095(6) nm, c = 1.0192(4)nm; α=96.54(4)°,β=106.18(3)°,γ=80.51(3)°;V=1. 4681(5)nm~3, Z=2, R = 0.068.此外,配合物1的Cu-O(1)键长[0.1880(5)nm]和可 见吸收波长(λ_(max)=557nm)比2[0.1982(6)nm,λ_(max)=605nm]短。配合物2在- 0。80～-1.20V范围内出现两个氧化和两个还原过程。     

Metal Complex Formation and Anticancer Activity of Cu(I) and Cu(II) Complexes with Metformin

Metformin has been used for decades in millions of type 2 diabetes mellitus patients. In this time, correlations between metformin use and the occurrence of other disorders have been noted, as well as unpredictable metformin side effects. Diabetes is a significant cancer risk factor, but unexpectedly, metformin-treated diabetic patients have lower cancer incidence. Here, we show that metformin forms stable complexes with copper (II) ions. Both copper(I)/metformin and copper(II)/metformin complexes form adducts with glutathione, the main intracellular antioxidative peptide, found at high levels in cancer cells. Metformin reduces cell number and viability in SW1222 and K562 cells, as well as in K562-200 multidrug-resistant cells. Notably, the antiproliferative effect of metformin is enhanced in the presence of copper ions.     

Synthesis,Characterization and Assessment of the Antioxidant Activity of Cu(II), Zn(II) and Cd(II) Complexes Derived from Scorpionate Ligands

Seeking to enrich the yet less explored field of scorpionate complexes bearing antioxidant properties, we, here, report on the synthesis, characterization and assessment of the antioxidant activity of new complexes derived from three scorpionate ligands. The interaction between the scorpionate ligands thallium(I) hydrotris(5-methyl-indazolyl)borate (TlTp^4Bo,5Me), thallium(I) hydrotris(4,5-dihydro-2H-benzo[g]indazolyl)borate (TlTp^a) and potassium hydrotris(3-tert-butyl- pyrazolyl)borate (KTp^tBu), and metal(II) chlorides, in dichloromethane at room temperature, produced a new family of complexes having the stoichiometric formula [M(Tp^4Bo,5Me)₂] (M = Cu, 1; Zn, 4; Cd, 7), [M(Tp^a)₂] (M = Cu, 2; Zn, 5; Cd, 8), [Cu(Hpz^tBu)₃Cl₂] (3), [Zn(Tp^tBu)Cl] (6) and [Cd(Bp^tBu)(Hpz^tBu)Cl] (9). The obtained metal complexes were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance and elemental analysis, highlighting the total and partial hydrolysis of the scorpionate ligand Tp^tBu during the synthesis of the Cu(II) complex 3 and the Cd(II) complex 9, respectively. An assessment of the antioxidant activity of the obtained metal complexes was performed through both enzymatic and non-enzymatic assays against 1,1-diphenyl-2-picryl- hydrazyl (DPPH^·), 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^+·), hydroxyl (HO^·), nitric oxide (NO^·), superoxide (O₂⁻) and peroxide (OOH^·) radicals. In particular, the complex [Cu(Tp^a)₂]⋅0.5H₂O (2) exhibited significant antioxidant activity, as good and specific activity against superoxide (O₂^−·), (IC50 values equal to 5.6 ± 0.2 μM) and might be identified as auspicious SOD-mimics (SOD = superoxide dismutase).     

Synthesis and Biological Activity of Some New Pyrazole Copper(II) Complexes

As a part of systematic investigation of synthesis and biologically active compounds of pyrazole derivatives containing transition metal, several new pyrazole copper(II) complexes 3a?f were synthesized from pyrazole sodium salts 2a?f , which were produced from spiro‐pyrazoles 1a?f and sodium hydride by a ring‐opening reaction. All the synthesized compounds were characterized by spectroscopic analysis. Pyrazole copper(II) complexes 3a?d and 3f exhibited high DNA cleavage activity in vitro. Furthermore, compounds 3a?f were tested for their growth inhibitory activity in A549 lung cancer, B16F10 murine melanoma, and HeLa human uterine carcinoma cells. Compounds 3c,d displayed moderate B16F10 and HeLa inhibitory activity levels ( 3c : IC₅₀ = 45 μM in B16F10 cells and 34 μM in HeLa cells, 3d : IC₅₀ = 50 μM in B16F10 cells and 32 μM in HeLa cells).     

Studies of Some New Aminocyclodiphosphazane Complexes of Co(II), Ni(II), and Cu(II)

The ligand aminocyclodiphosph(V)azane derivative (III) and its complexes with Co(II), Ni(II), and Cu(II) ions were prepared and characterized by microanalytical, FTIR, ¹H, ¹³C, and ³¹P-NMR, UV/Visible, thermogravimetric (TGA) analysis, and magnetic moments. The ligand acts in a tetrahedral manner forming 2:1 metal to ligand ratio. The copper complex is assigned to be tetrahedral while cobalt and nickel complexes were assigned to be octahedral structure.     

Catalytic Activity of Pt(II) Complexes in Addition of Tetrachloromethane to Alkenes

Russian Journal of General Chemistry -     

Organoplatinum(II) Complexes with Nucleobase Motifs as Inhibitors of Human Topoisomerase II Catalytic Activity

Platinum(II) complexes bearing acetylide ligands containing nucleobase motifs are prepared and their impact on human topoisomerase II (TopoII) is evaluated. Both platinum(II) complexes [Pt^II(C^N^N)(C≡CCH₂R)] ( 1a , 1b , 1c ) and [Pt^II(tBu₃terpy)(C≡CCH₂R)]⁺ ( 2a , 2b , 2c ) (C^N^N=6‐phenyl‐2,2′‐bipyridyl, tBu₃terpy = 4,4′,4′′‐tri‐tert‐butyl‐2,2′:6′,2′′‐terpyridyl, and R=( a ) adenine, ( b ) thymine, and ( c ) 2‐amino‐6‐chloropurine) are stable in aqueous solutions for 48 hours at room temperature. The binding constants (K) for the platinum(II) complexes towards calf thymus DNA are in the order of 10⁵ dm³ mol^?1 as estimated by using UV/Vis absorption spectroscopy. Of the complexes examined, only complexes 1a , 1b , 1c are found to behave as intercalators. Both complexes 1a , 1b , 1c and 2a , 2b , 2c inhibit TopoII‐induced relaxation of supercoiled DNA, while 2c is the most potent TopoII inhibitors among the tested compounds. Inhibition of DNA relaxation is detected at nanomolar concentrations of 2c . All of the platinum(II) complexes are cytotoxic to human cancer cells with IC₅₀ values of 0.5–13.7 μM , while they are less toxic against normal cells CCD‐19 Lu.     

Preparation,Characterization, Biological Activity and 3D Molecular Modeling of Mn(II), Co(II), Ni(II), Cu(II), Pd(II) and Ru(III) Complexes of Some Sulfadrug Schiff Bases

Mn(II), Co(II), Ni(II), Cu(II), Pd(II) and Ru(III) complexes of Schiff bases derived from the condensation of sulfaguanidine with 2,4‐dihydroxy benzaldehyde ( HL1 ), 2‐hydroxy‐1‐naphthaldehyde ( HL2 ) and salicylaldehyde ( HL3 ) have been synthesized. The structures of the prepared metal complexes were proposed based on elemental analysis, molar conductance, thermal analysis (TGA, DSC and DTG), magnetic susceptibility measurements and spectroscopic techniques (IR, UV‐Vis, and ESR). In all complexes, the ligand bonds to the metal ion through the azomethine nitrogen and α‐hydroxy oxygen atoms. The structures of Pd(II) complex 8 and Ru(III) complex 9 were found to be polynuclear. Two kinds of stereochemical geometries; distorted tetrahedral and distorted square pyramidal, have been realized for the Cu(II) complexes based on the results of UV‐Vis, magnetic susceptibility and ESR spectra whereas octahedral geometry was predicted for Co(II), Mn(II) and Ru(III) complexes. Ni(II) complexes were predicted to be square planar and tetrahedral and Pd(II) complexes were found to be square planar. The antimicrobial activity of the ligands and their metal complexes was also investigated against the gram‐positive bacteria Staphylococcus aures and Bacillus subtilis and gram‐negative bacteria, Escherichia coli and Pesudomonas aeruginosa, by using the agar dilution method. Chloramphenicol was used as standard compound. The obtained data revealed that the metal complexes are more or less, active than the parent ligand and standard. The X‐ray crystal structure of HL3 has been also reported.     

Magnetic and Spectroscopic Studies on the Complexes of 9-Oxo-10-Acridinemetanophosphonic Ion with Cu (II) Co (II)and Ni (II)

Abstract

Three complexes of 9-oxo-10-acridinemetanophosphonlc ion (PMA⁼ see figure) have been synthesised. The meta1:ligand ratio in the complexes is equal 1:1 and their formulas are (CUPMA) ₂,×5H₂O,NiPMA×4H₂O and CoPMA×4H₂O. The structure of the complexes has been investigated by the IR,FIR, Raman spectroscopy, UV-VIS spectroscopy, magnetic measurements and EPR spectroscopy. The physical properties of the complexes obtained are characteristic for inorganic polymers. The lowering of the ν(P-Q) stretching frequency by about cm^?, in the spectra of the complexes as compared to that of the free ligand suggests that the phosphonlc group takes part in coordination. Data from the EPR spectrum indicate that Cu(II)may form the dimeric, water bridged or even more complicated polymeric structures.     

Synthesis,Characterization, and Catalytic Activity of New Cu(II) Complexes of Schiff Base: Effective Catalysts for Decolorization of Acid Red 37 Dye Solution

In this paper, three new Cu(II) Schiff base complexes with three different anions (acetate, chloride, and nitrate) were successfully synthesized and characterized by elemental analysis, mass spectra, molar conductance, FT‐IR, NMR,UV–vis spectroscopy, magnetic moment, ESR, and thermal analysis. The catalytic performances of these complexes in decolorization of azo dye, Acid Red 37, were evaluated. Copper(II) complexes were found to be an efficient catalyst for decolorization of Acid Red 37 in the presence of hydrogen peroxide. The catalytic investigation revealed that the Cu(II) complex with acetate anion (complex 1 ) performed the highest catalytic activity. The kinetics of the decolorization of AR37 with this catalyst was studied, and the observed rate constant was determined. The effects of different reaction parameters such as catalyst dosage, solution pH, initial concentration of H₂O₂, dye solution, and reaction temperature on the reaction rate constant were studied. The best reacting conditions should be catalyst dosage = 0.004 g, initial pH 4.0, [H₂O₂]₀ = 0.8 M, and [AR37]₀ = 1.16 M at temperature 25°C. Under these conditions, about 99% of AR37 was decolorized within 60 min. The results indicated that the Cu(II) complex with the acetate anion is a promising catalyst for wastewater treatment.     

Phen-铜(II)-氨基酸配合物的合成、表征及其SOD活性

合成了3个新的SOD模拟配合物：[Cu(Phen)(L-Gln)(H₂O)]Cl·2H₂O (1)、[Cu(Phen)(L-Ala)(H₂O)]Cl·4H₂O (2)、[Cu(Phen)(L-Thr)(H₂O)]Cl·2H₂O (3) [Phen(1，10-邻菲咯啉)、L-Gln(谷氨酰胺)、L-Ala(丙氨酸)、L-Thr(苏氨酸)]。用元素分析、摩尔电导、红外光谱、紫外-可见光谱对配合物进行了表征。用X-射线衍射对配合物[Cu(Phen)(L-Gln)(H₂O)]Cl·2H₂O的晶体结构进行了测定。用氯化硝基四氮唑蓝(NBT)光还原法对这3个配合物催化歧化超氧阴离子自由基(O₂^{- ·})的能力进行了测定。结果表明：这些配合物具有较高的SOD活性， 催化速率常数K_Q分别为1.58 × 10⁷ mol^-1·L·s^-1、5.65 × 10⁷ mol^-1·L·s^-1、0.83 × 10⁷ mol^-1·L·s^-1。     

Diorganotin Complexes with N(4)-Phenylthiosemicarbazones: Synthesis,Spectroscopic Characterization,and Antibacterial Activity

Abstract

The organotin(IV) complexes, SnPh₂L^a (1), SnMe₂L^a (2), SnBu₂L^a (3), SnPh₂L^b (4), SnMe₂L^b (5), SnPh₂L^c (6), SnMe₂L^c (7), and SnBu₂L^c (8) were obtained by reaction of SnR ₂Cl₂ (R = Ph, Me, and Bu) with 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide (H₂L^a), 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide (H₂L^b), and 1-(2-hydroxy-3-methoxybenzylidene)-4-phenylthiosemicarbazide (H₂L^c). The synthesized complexes have been investigated by elemental analysis, IR, ¹H NMR, and ¹¹⁹Sn NMR spectroscopy. The data show that the thiosemicarbazone acts as a tridentate dianionic ligand and coordinates via the thiol group, imine nitrogen, and phenolic oxygen. The coordination number of tin is 5. The in vitro antibacterial activities of the ligands and their complexes have been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and compared with the standard antibacterial drugs.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures and tables]     

Synthesis, Characterization and the Antioxidative Activity of Zinc(II), Copper(II) and Nickel(II) Schiff-base Complexes

A naringenin Schiff-base ligand (H₃L) and its three complexes, MHL . nH₂O (M = Zn and Cu, n = 0.5) and NiH₂LOAc . 3.5H₂O, have been synthesized and characterized on the basis of elemental analysis, molar conductivity and i.r. spectrum, ¹H-n.m.r., u.v. spectra and thermal analyses. In addition, the suppression ratio for O₂^−˙ (a) and the suppression ratio for OH˙(b) were determined by the use of spectrophotometric methods. IC₅₀(a) and IC₅₀(b) of the complexes are given. The results show that compared to the ligand, the complexes exhibit high activity in the suppression of O₂^−˙ (a) and OH˙(b).     

Synthesis and Characterization of New Mononuclear Ru (II) PolypyridylComplexes with Catalytic Activity

In this work, we report the synthesis and physicochemical characterization of new chloro and aqua mononuclear Ru (II) complexes of formula [Ru(LLL)(dpp)Cl]PF₆ and [Ru(LLL)(dpp)OH₂](PF₆)₂ (LLL=tpy =2,2’ : 6’,2’’-terpyridine; tptz=2,4,6-tris(2-pyridyl)-1,3,5-triazine and dpp=2,3-bis(2-pyridil)pyrazine). For the complex [Ru(tptz)(dpp)Cl]PF₆, the complete structure was determined by X-ray diffraction. Catalytic studies of aqua-complexes revealed that they are active for the water oxidation reaction at pH 1 using cerium ammonium nitrate (CAN) as a sacrificial oxidant. Also, we were able to establish the reaction mechanism and rate constants of each stage of the catalytic cycle, turnover frequencies (TOFs), and turnover numberes (TONs). The experimental TON values for the aqua complexes were very close to the theoretical value of 7.5, indicating a high degree of recovery. DFT and TD-DFT calculations of electronic states for all complexes were consistent with experimental results and allowed the complete assignment of their UV-Visible bands and redox states.     

Synthesis,Characterization and Anti-oxidative Activity of Cobalt(II), Nickel(II) and Iron(II) Schiff Base Complexes

Six complexes, M(HL)₂ · nH₂O (M=Co, Ni and Fe; n=4) with two ligands, 2-carboxy-benzaldehydebenzoylhydrazone (H₂L¹) and 2-carboxybenzaldehyde-(4′-methoxy)benzoylhydrazone (H₂L²), have been synthesized and characterized on the basis of elemental analyses, molar conductivities, i.r. spectra and thermal analyses. In addition, the suppression ratio for O₂^- (a) and the suppression ratio for OH^· (b) were determined with a 72 spectrophotometer. The 50% inhibition [IC₅₀ (a) and IC₅₀ (b)] of the complexes were studied. This study demonstrated that the complexes have activity in the suppression of O₂^- (a) and OH^· (b). In general, the antioxidative activities increased as the concentration of these complexes increased up to a selected extent. The complexes exhibit more effective antioxidants than the ligands and the series of the ligand (H₂L²) are better than the series of the ligand (H₂L¹) do.     

Spectroscopic and Electrochemical Behavior of Cyclometalated Pd(II) Complexes

The absorption and emission spectra, emission lifetimes, luminescence quantum yields, and electrochemical behavior of the complexes Pd(Phpy)₂, Pd(Thpy)₂, and Pd(bhq)₂ (Phpy^?, Thpy^?, and bhq^?, and bhq^? are the deprotonated forms of 2-phenylpyridine, 2-(2-thienyl)pyridine, and benzo[h] quinoline, respectively) have been studied, and the results obtained have been compared with those available for Pt(II) and Pt(IV) complexes containing the same ligands. The intense ligand-centered absorption bands below 340 nm are strongly perturbed by matalation, and the absorption features in the 340–450-nm region are likely to include contributions from formally metal-to-ligand charge-transfer transitions. The structured luminescence spectra observed at 77 K (lifetimes are 0.48, 0.28 and 2.6 ms for Pd(Phpy)₂, Pd(Thpy)₂, and Pd(bhq)₂, respectively) have been assigned to transitions having mainly ligand-centered character, with an increasing metal-to-ligand charge-transfer contribution in going from Pd(bhq)₂ to Pd(Phpy)₂ and to Pd(Thpy)₂. The complexes Pd(phpy)₂ and Pd(thpy)₂ show two reversible one-electron reduction waves, whereas reduction of Pd(bhq)₂ is irreversible, as is the oxidation of the three complexes.