Copper(II) Complexes of Spirohydantoins. Synthesis,Quantum-Chemical,and Spectroscopic Study

A series of new Cu(II) complexes with important physiologically active cycloalkane-5-spirohydantoines are synthesized reacting as a result of CuCl₂ · 2H₂O interaction with the ligands in alkaline water medium. Their structures were studied using spectroscopic (IR and EPR) methods. For comparison, ab initio calculations of the structure and IR spectra of the corresponding Cu(II) complexes were also performed. It was proven that with cyclopentane-5-spirohydantoins, distorted (flattened) tetrahedral structure is realized Cu(L_–H)₂(H₂O)₂, while with the higher cycloalkane-5-spirohydantoins linear Cu(II) complexes of the type CuL_–H(OH) are formed.     

Synthesis and Structure of Copper(II) Phosphonodithioite Complexes

A series of new complexes of CuBr with phosphonodithioites were prepared and characterized by NMR and IR spectroscopy. As shown by single crystal X-ray diffraction, diethyl tert-butylphosphonodithioite forms with CuBr a tetrameric cubane-like complex with the monodentate coordination of the organophosphorus ligand via the P atom.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 903–907.Original Russian Text Copyright © 2005 by Kursheva, Kataeva, Perova, Batyeva, Sinyashin, Freilich.     

Novel Cobalt(II), Nickel(II) and Copper(II) Complexes of Neutral Orotic Acid. Synthesis,Spectroscopic and Thermal Studies

The new orotic acid complexes, [MCl₂(H₂O)₃(H₃Or)], M=Co(II), Ni(II) and [CuCl₂(H₂O)(H₃Or)₃] · H₂O, were synthesized and characterized by elemental analysis, magnetic susceptibility, spectral (Diffuse reflectance UV–Vis and FTIR) methods, and simultaneous thermal analysis (TG, DTG and DTA) techniques. Physical measurements indicate that the neutral orotic acid ligands are bonded to metal ions through the carbonyl groups. Two thermal processes of the complexes can occur: dehydration and pyrolytic decomposition. On the basis of the DTG_max, the thermal stability of the complexes follows the order: Co(II) (122 °C) > Cu(II) (77 °C) > Ni(II) (66 °C).     

Synthesis, Crystal Structure and Properties of Polyamine Copper(II) Complexes

Two polyamine copper(II) complexes were synthesized by the reaction between N,N,N′,N′-tetrakis(2′-aminoethyl)propane-1,2-diamine hexahydrochloride and copper(II) perchlorate under almost the same conditions except for reaction temperature. The crystal structures of two complexes were determined by X-ray diffraction techniques, which shows that one of the complexes is unexpected and is a double chlorine or chloride-bridged dinuclear copper(II) complex formed by two diethylenetriamines, and another is a pentadentate mononuclear copper(II) complex composed of homo-protonated N,N,N′,N′-tetrakis(2′-aminoethyl)propane-1,2-diamine. The mechanism of the reaction leading to form the unexpected complex was discussed. The UV-visible spectra and cyclic voltammogram of the complexes were measured.     

Synthesis and Characterization of Tris(oxazolinyl)borato Copper(II) and Copper(I) Complexes

The reaction of To^MTl (To^M=tris(4,4-dimethyl-2-oxazolinyl)phenylborate) and CuBr₂ in benzene at 60 °C provides To^MCuBr ( 1 ) as an entry-point into tris(oxazolinyl)phenylborato copper chemistry. To^MCuO^tBu ( 2 ) and To^MCuOAc ( 3 ) are prepared by the reactions of To^MCuBr with KO^tBu and NaOAc, respectively. To^MCuO^tBu is transformed into (To^MCuOH)₂ ( 4 ) through hydrolysis. NMR, FT-IR, and EPR spectroscopies are used to determine the electronic and structural properties of these copper(II) compounds, and the solid-state structures were characterized by X-ray crystallography. Reduction of copper is observed upon treatment of To^MCuO^tBu with phenylsilane in an attempt to synthesize monomeric copper(II) hydride. To^MCu ( 5 ) and To^M₂Cu ( 6 ) were independently synthesized and characterized for comparison.     

Synthesis, Characterization and the Antioxidative Activity of Copper(II), Zinc(II) and Nickel(II) Complexes with Naringenin

New complexes of Cu^(II), Zn^(II) and Ni^(II) with naringenin have been synthesized and characterized on the basis of elemental analyses, molar conductivities, ¹H-n.m.r., i.r. spectra, u.v. spectra, thermal analyses, and fluorescence spectra. In addition, the suppression ratio for O₂⁻· (a) and OH· (b) of the complexes were studied by spectrophotometric methods. The results show that the effect of the Cu^(II)-complex IC₅₀ (a) = 0.003 μm, IC₅₀ (b) = 0.06 μm is the most remarkable, and the average scavenger ability of the complexes (IC₅₀=0.06–2.67μm) against OH· is higher than that of the ligand (IC₅₀ = 28.5 μm). Taken together, these results indicate that the scavenger effect can be enhanced by the formation of metal-ligand coordination complexes, and the transition-metal ions may have differential and selective roles.     

无机化学综合实验:Cu(I)配合物的合成与光致发光性能

Cu（I）配合物的合成与光致发光性能实验是结合无机化学中的配合物基础知识和前沿研究热点设计的综合性实验,包括配合物的制备和光致发光性质表征。本实验中分别制备了立方烷、阶梯状、二聚体等不同结构和不同配体的Cu（I）配合物,深入研究了光致发光性能与配合物结构之间的关系。该实验共需12学时完成,实验过程包括配合物制备、减压过滤、荧光光谱测试与分析等,涉及沉淀溶解、配位等多种反应类型和分子光物理性质探究。该综合性实验对实验设备要求低,实验现象明显,产率高,教学过程可操作性强,综合性强。教学实践表明,该实验能显著激发学生学习兴趣,不仅可以让学生加深对无机化学基础知识的理解,还可以获取前沿知识,对提高学生的综合实验能力,培养创新型、复合型人才具有重要意义。     

Synthesis and Structure of Different-Metal Different-Ligand Germanium(IV) and Cobalt(II) or Copper(II) Complexes with 1-Hydroxyethylidenediphosphonic Acid and 1,10-Phenanthroline

Different-metal different-ligand complexes [{Co(Phen)₃}₂{Co(Phen)(H₂O)₄}₂][{Ge(μ-OH)(μ- Hedp)}₆Cl₂] (I), [{Cu(Phen)₂(H₂O)}₂(HPhen)₂][Ge(μ-OH)(μ-Hedp)]₆ · 20H₂O (II) (H₄Hedp = 1-hydroxyethylidenediphosphonic acid, Phen = 1,10-phenanthroline) were synthesized and studied by X-ray diffraction. According to X-ray diffraction data (CIF files CCDC nos. 1573112 (I), 1573113 (II)), compounds I and II are cation–anion type complexes in which the anions are represented by {[Ge(μ-OH)(μ-Hedp)]⁶}^6– and, in the case of I, two additional Cl^– ions, while the cations are [Co(Phen)₃]²⁺, [Co(Phen)(H₂O)₄]²⁺ in I and [Cu(Phen)₂(H₂O)]²⁺, HPhen⁺ in II. In the crystals of compounds I and II, the cations, anions, and water molecules are combined by numerous intermolecular hydrogen bonds, giving rise to a 3D network.     

Synthesis,Crystal Structures and Magnetic Properties of Copper(II) Complexes with Nitronyl Nitroxide Radicals

Two new copper(II) compounds with imino nitroxide radicals [Cu(IM‐MeImz)₂ · (SCN)] 0.5[Cu(SCN)₄] ( 1 ) and [Cu(IM‐MeImz)₂ · (SCN)]ClO₄ · H₂O ( 2 ) (IM‐meImz = 2‐(5‐methylimidazol‐4‐yl)‐4,4,5,5‐tetramethyl‐2‐imidazoline‐1‐oxyl) have been synthesized and characterized structurally and magnetically. X‐ray analysis demonstrates that complex 1 contains Cu^II ions in both square‐pyramidal and square planar coordination. There are complete charge separation into [Cu(IM‐MeImz)₂(SCN)]⁺ cations and 0.5[Cu(SCN)₄]^? anions, in a 2:1 ratio. The complex 1 was connected as a one‐dimensional polymer by intermolecular interactions. In complex 2 , the coordination around the copper atom is distorted square pyramidal and the apical position is occupied by one nitrogen atom of SCN^? anion. The 2‐D network structure was formed and arranged through intermolecular H‐bonds interactions. The complex 1 exhibits intramolecular weak ferromagnetic coupling between Cu^II ion and the radicals.     

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,Characterization, and Non-Covalent Interactions of Palladium(II)-Amino Acid Complexes

The reaction of palladium(II) acetate with acyclic amino acids in acetone/water yields square planar bis-chelated palladium amino acid complexes that exhibit interesting non-covalent interactions. In all cases, complexes were examined by multiple spectroscopic techniques, especially HRMS (high resolution mass spectrometry), IR (infrared spectroscopy), and ¹H NMR (nuclear magnetic resonance) spectroscopy. In some cases, suitable crystals for single crystal X-ray diffraction were able to be grown and the molecular structure was obtained. The molecular geometries of the products are discussed. Except for the alanine complex, all complexes incorporate water molecules into the extended lattice and exhibit N-H···O and/or O···(HOH)···O hydrogen bonding interactions. The non-covalent interactions are discussed in terms of the extended lattice structures exhibited by the structures.     

Copper(II) Complexes with Chiral Ligands Containing Fragments of Monoterpenoids and Amino Acid Esters

Complexes [CuL¹Cl₂] (I), [CuL²Cl₂] · EtOH (II), and Cu₂L³Cl₄ (III) containing esters of the N-derivatives of optically active amino acids based on (+)-3-carene (L¹, L²) and (?)-α-pinene (L³) are synthesized. The crystal and molecular structures of compounds I and II are determined by X-ray diffraction analyses (CIF files CCDC nos. 1560071 (I), 1560072 (II)). The crystal structure of compound I consists of mononuclear complex molecules. In the structure of compound II, the unit cell contains two crystallographically independent molecules of mononuclear complex [CuL²Cl₂] and two EtOH molecules. Ligands L¹ and L² perform the tridentate-chelating function by the N atoms of the NH and NOH groups and by the O atom of the C=O group. In compounds I and II, the coordination polyhedra Cl₂N₂O of the Cu atoms are trigonal bipyramid. According to the data of IR and electronic spectroscopy, binuclear complex III has similar coordination polyhedra. The experimental values of μ_eff for compounds I, II, and III at 300 K are 1.93, 1.88, and 2.71 μB. For complex III, the μ_eff(T) dependence in a range of 2–300 K indicates a weak ferromagnetic exchange interaction.     

Novel Copper(II) Complexes with Dipinodiazafluorene Ligands: Synthesis,Structure, Magnetic and Catalytic Properties

The reactions of CuX₂ (X = Cl, Br) with dipinodiazafluorenes yielded four new complexes [CuX₂L₁]₂ (X = Cl (1), Br (2), L₁ = (1R,3R,8R,10R)-2,2,9,9-Tetramethyl-3,4,7,8,9,10-hexahydro-1H-1,3:8,10-dimethanocyclopenta [1,2-b:5,4-b’]diquinolin-12(2H)-one) and [(CuX₂)₂L₂]n (X = Cl (3), Br (4), L₂ = (1R,3R,8R,10R,1’R,3’R,8’R,10’R)-2,2,2’,2’,9,9,9’,9’-Octamethyl-1,1’,2,2’,3,3’,4,4’,7,7’,8,8’,9,9’,10,10’-hexadecahydro-1,3:1’,3’:8,10:8’,10’-tetramethano-12,12’-bi(cyclopenta [1,2-b:5,4-b’]diquinolinylidene). The complexes were characterized by IR and EPR spectroscopy, HR-ESI-MS and elemental analysis. The crystal structures of compounds 1, 2 and 4 were determined by X-ray diffraction (XRD) analysis. Complexes 1–2 have a monomeric structure, while complex 4 has a polymeric structure due to additional coordinating N,N sites in L₂. All complexes contain a binuclear fragment {Cu₂(μ-X)_2×2} (X = Cl, Br) in their structures. Each copper atom has a distorted square-pyramidal coordination environment formed by two nitrogen atoms and three halogen atoms. The Cu-N_ax distance is elongated compared to Cu-N_eq. The EPR spectra of compounds 1–4 in CH₃CN confirm their paramagnetic nature due to the d⁹ electronic configuration of the copper(II) ion. The magnetic properties of all compounds were studied by the method of static magnetic susceptibility. For complexes 1 and 2, the effective magnetic moments are µ_eff ≈ 1.87 and 1.83 µ_B (per each Cu²⁺ ion), respectively, in the temperature range 50–300 K, which are close to the theoretical spin value (1.73 µ_B). Ferromagnetic exchange interactions between Cu(II) ions inside {Cu₂(μ-X)₂X₂} (X = Cl, Br) dimers (J/k_B ≈ 25 and 31 K for 1 and 2, respectively) or between dimers (θ′ ≈ 0.30 and 0.47 K for 1 and 2, respectively) were found at low temperatures. For compounds 3 and 4, the magnetic susceptibility is well described by the Curie–Weiss law in the temperature range 1.77–300 K with µ_eff ≈ 1.72 and 1.70 µ_B for 3 and 4, respectively, and weak antiferromagnetic interactions (θ ≈ −0.4 K for 3 and −0.65 K for 4). Complexes 1–4 exhibit high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The maximum yield of cyclohexane oxidation products reached 50% (complex 3). Based on the data on the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play a decisive role in the oxidation reaction. The initial products in reactions with alkanes are alkyl hydroperoxides.     

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。     

Synthesis and Crystal and Molecular Structures of Nickel(II) and Copper(II) 1,5-Napthalenedisulfonate Complexes with Nicotinamide

Russian Journal of Coordination Chemistry - Coordination compounds of nickel(II) and copper(II) 1,5-naphthalenedisulfonates with nicotinamides, [Ni(L)2(H2O)4](Nds) · 3H2O (I) and...     

Dinuclear Five‐Coordinate Copper(II) Complexes with Chelating Diphosphonic Acid Ligands: Hydrothermal Synthesis,Structure, and Thermal Properties

The synthesis of two new diphosphonic acid ligands,[ethane‐1, 2‐diylbis(azanediyl)]bis[(4‐chlorophenyl)methylene]diphosphonic acid (L₁P), [ethane‐1, 2‐diylbis(azanediyl)]bis[(4‐bromophenyl)methylene]diphosphonic acid (L₂P), and their corresponding copper complexes, Cu₂(L₁P)₂ ( 1 ) and Cu₂(L₂P)₂ ( 2 ) are described herein. Complex 2 was structurally characterized with X‐ray single crystal diffraction. The structure of 2 consists of five‐coordinatecopper(II) ions with a distorted square pyramidal arrangement doubly bridged by OPO from phosphonate groups. The Cu–Cu distance is 4.7810(2) Å. The crystal packing is determined by interdinuclear hydrogen bonds, which lead to one‐dimensional chains. The results of thermogravimetric investigations (TG‐DTA), UV/Vis diffuse reflectance, infrared and (¹H and ¹³C) NMR spectroscopy, as well as elemental analyses of compounds 1 and 2 are also presented.     

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).     

Structure, Stability, and Lability of Copper(II) Complexes with Triglycine

Equilibrium constants of complex formation, rate constants of chemical exchange reactions, and characteristics of electronic absorption spectra for species detected in aqueous solution of copper(II) with triglycine were determined, and conclusions on the structure of the complexes were made. A possibility of H-bond formation between the ammonium group of the zwitter-ionic form of the ligand and the second peptide oxygen in the anionic form of an adjacent ligand was shown. Kinetics and mechanisms of ligand and proton exchanges in solutions of copper(II) bistripeptide complexes with the ligand containing a deprotonated peptide nitrogen atom were studied. A new mechanism was proposed for hydroxide-catalyzed substitution reactions in copper(II) complexes with tripeptides.     

Synthesis,Characterization and Evaluation of the Antibacterial and Antitumor Activity of HalogenatedSalen Copper (II) Complexes derived from Camphoric Acid

Platinum metal complexes are the most common chemotherapeutics currently used in cancer treatment. However, the frequent adverse effects, as well as acquired resistance by tumor cells, urge the development of effective alternatives. In the recent past, copper complexes with Schiff base ligands have emerged as good alternatives, showing interesting results. Accordingly, and in continuation of previous studies in this area, three new camphoric acid-derived halogenated salen ligands and their corresponding Cu (II) complexes were synthesized and their antitumor activity was evaluated in order to determine the influence of the type and number of halogens present (Br, Cl). The in vitro cytotoxic activity was screened against colorectal WiDr and LS1034 and against breast MCF-7 and HCC1806 cancer cell lines. The results proved the halogenated complexes to be very efficient, the tetrachlorinated Cu (II) complex being the most promising, presenting IC₅₀ of 0.63–1.09 μM for the cell lines studied. The complex also shows selectivity to colorectal cancer cells compared to non-tumor colon cells. It is worth highlighting that the tetrachlorinated Cu (II) complex, our most efficient complex, shows a significantly more powerful antitumor effect than the reference drugs currently used in conventional chemotherapy. The halogenated salen and corresponding complexes were also screened for their antimicrobial activity against four bacterial species-Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa-and four fungal species-Candida albicans, Candida glabrata, Aspergillus fumigatus and Alternaria alternata. The compounds were found to exhibit moderate to strong antibacterial activity against the bacterial strains studied. NMR studies and theoretical calculations provided some insight into the structure of the ligands and copper complexes. Considering the results presented herein, our work validates the potential use of copper-based chemotherapeutics as alternatives for cancer treatment.     

Chromium(II) Complexes with Hydroxyethylidenediphosphonic Acid

The complex formation of chromium(II) with hydroxyethylidenediphosphonic acid (HEDP, H₅L) in an aqueous solution is studied by spectrophotometry. The pH region is determined where the HEDP complexonates of chromium(II) are stable. The effect of pH on the complexation and the composition of the coordination sphere of the complex ions is shown. The optimum conditions for the practical application of HEDP as a stabilizing ligand are chosen. The instability constants for tetra-, tri-, di-, and monoprotonated and neutral chromium(II) hydroxyethylidenediphosphonate complexes were calculated, whose pK were found to be 1.21, 2.43, 6.87, 12.60, 19.40, respectively. A new complex of chromium(II), Na₄[Cr(H₂L)₂ · 2H₂O] · 4H₂O, was isolated from a solution and characterized using elemental, IR spectroscopic, and thermographic analyses.