An investigation of two copper(ii) complexes with a triazole derivative as a ligand: magnetic and catalytic properties.
Ontology highlight
ABSTRACT:
SUBMITTER: Petrenko YP
PROVIDER: S-EPMC9036593 | biostudies-literature | 2021 Jul
REPOSITORIES: biostudies-literature
Publications
An investigation of two copper(ii) complexes with a triazole derivative as a ligand: magnetic and catalytic properties.
Petrenko Yuliia P YP Piasta Karolina K Khomenko Dmytro M DM Doroshchuk Roman O RO Shova Sergiu S Novitchi Ghénadie G Toporivska Yuliya Y Gumienna-Kontecka Elzbieta E Martins Luísa M D R S LMDRS Lampeka Rostyslav D RD
RSC advances 20210702 38
Two new copper(ii) complexes [Cu<sub>2</sub>(L)<sub>2</sub>(OAc)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] (1) (L = 3-methyl-5-pyridin-2-yl-1,2,4-triazole) and [CuL<sub>2</sub>] (2) were prerared and thoroughly studied. The complexes are able to selectively catalyze the oxidation of styrene towards benzaldehyde and of cyclohexane to KA oil. The 2D coordination polymer 1 showed an antiferromagnetic behaviour attributed to the intrachain magnetic coupling. ...[more]
Similar Datasets
Project description: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-Nax distance is elongated compared to Cu-Neq. 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 µeff ≈ 1.87 and 1.83 µB (per each Cu2+ ion), respectively, in the temperature range 50-300 K, which are close to the theoretical spin value (1.73 µB). Ferromagnetic exchange interactions between Cu(II) ions inside {Cu2(μ-X)2X2} (X = Cl, Br) dimers (J/kB ≈ 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 µeff ≈ 1.72 and 1.70 µB 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.
| S-EPMC9268630 | biostudies-literature
Project description:A series of copper complexes (3-6) stabilized by 1,2,3-triazole-tethered N-heterocyclic carbene ligands have been prepared via simple reaction of imidazolium salts with copper powder in good yields. The structures of bi- and trinuclear copper complexes were fully characterized by NMR, elemental analysis (EA), and X-ray crystallography. In particular, [Cu2(L2)2](PF6)2 (3) and [Cu2(L3)2](PF6)2 (4) were dinuclear copper complexes. Complexes [Cu3(L4)2](PF6)3 (5) and [Cu3(L5)2](PF6)3 (6) consist of a triangular Cu3 core. These structures vary depending on the imidazolium backbone and N substituents. The copper-NHC complexes tested are highly active for the Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction in an air atmosphere at room temperature in a CH3CN solution. Complex 4 is the most efficient catalyst among these polynuclear complexes in an air atmosphere at room temperature.
| S-EPMC4901887 | biostudies-literature
Project description:Two mononuclear zero-dimensional Ni(II) and Zn(II) complexes bearing diethylenetriamine derivative ligand, namely [NiL(CH3COO)2(H2O)] (1) and [ZnL(CH3COO)2] (2) [L = N, N'-bis(2-hydroxybenzyl)diethylenetriamine], were synthesized under reflux conditions. The molecular composition and structure of the complexes were identified by IR, PXRD, elemental analyses, and single crystal X-ray diffraction. Complex 1 belongs to a monoclinic crystal system with the P21/n space group, and Complex 2 belongs to a monoclinic crystal system with the C2/c space group. The Henry reaction of nitromethane with aromatic aldehydes was explored with Complexes 1 and 2 as the catalyst. Results from the catalytic reaction revealed that the complexes displayed excellent catalytic activities under the optimized conditions and that the substrate scope of aromatic aldehydes could be extended to a certain extent. In addition, the possible catalytic mechanism of the Henry reaction was also deduced.
| S-EPMC7248821 | biostudies-literature
Project description:Reaction of Cu(hfac)2 with methyl- and bromo-3-pyridyl-substituted nitronyl nitroxides (L R ) leads to assemble a diverse set of coordination complexes: mononuclear [Cu(hfac)2L 2-Me ], binuclear [{Cu(hfac)2}2(H2O)L 2-Me ], trinuclear [{Cu(hfac)2}3(L 6-Br )2], pentanuclear [{Cu(hfac)2}5(L 2-Me )2], and [{Cu(hfac)2}5(L 2-Me )4], cocrystals [Cu(hfac)2(L 2-Br )2]·[Cu(hfac)2(H2O)2] and [Cu(hfac)2(L 2-Br )2]·2[Cu(hfac)2H2O], one-dimensional polymers [Cu(hfac)2L 2-Br ] n and [Cu(hfac)2L 6-Br ] n , and cyclic dimers [Cu(hfac)2L 5-Me ]2, [Cu(hfac)2L 5-Br ]2, and [Cu(hfac)2L 6-Me ]2. The molecular structures of the obtained complexes are strongly affected by the substituent type and its location in the pyridine heterocycle. Occupation of the second position of the pyridine ring increases the steric hindrance of both imine and nitroxide coordination sites of L 2-R , which is favorable for the formation of various conformers and precipitation of complexes with different molecular structures. The pentanuclear [{Cu(hfac)2}5(L 2-Me )2] and [{Cu(hfac)2}5(L 2-Me )4] complexes do not have prior analogues and are valuable model objects for investigation of the mechanism of formation of various coordination polymers. The arrangement of long Cu-ONO bonds in {CuO6} square bipyramids due to the weakening nitroxide donor site in complexes, based on L 2-Me , L 2-Br , and L 6-Br ligands, results in ferromagnetic exchange interactions between spins of Cu2+ ions and nitroxides. Complexes with substituents that do not considerably affect the coordination ability of ligands (L 5-Me , L 5-Br , and L 6-Me ) exhibit strong antiferromagnetic exchange interactions between spins of Cu2+ ions and nitroxides.
| S-EPMC6811855 | biostudies-other
Project description:A novel POM-based trinuclear copper(ii) triazole framework, namely, [H2{Cu6(trz)6(μ3-OH)2}Mo5O18]·3H2O (1) was isolated using a hydrothermal method, which displays a 3D network constructed from trinuclear copper(ii) units and triazole ligands with [Mo5O18]6- anions as templates. 1 has been identified by single crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, powder X-ray diffraction and FT-IR. Magnetic studies indicate that antiferromagnetic interactions exist in 1. In addition, 1 exhibits good Lewis acid catalytic activity for the synthesis of cyclohexanone ethylene ketal with 95% conversion. The HOMO-LUMO gap (E g) of 1 is 2.34 eV calculated using the Kubelka-Munk equation (Fhν)0.5, indicating that its forbidden bandwidth belongs to the semiconductor category. Visible-light photodegradation of RhB catalyzed by 1 was investigated, which shows high activity with an above 98% degradation rate.
| S-EPMC9077210 | biostudies-literature
Project description:Cysteine plays an essential role in maintaining cellular redox homeostasis and perturbations in cysteine concentration are associated with cardiovascular disease, liver disease, and cancer. 19F MRI is a promising modality for detecting cysteine in biology due to its high tissue penetration and negligible biological background signal. Herein we report fluorinated macrocyclic copper complexes that display a 19F NMR/MRI turn-on response following reduction of the Cu(ii) complexes by cysteine. The reactivity with cysteine was studied by monitoring the appearance of a robust diamagnetic 19F signal following addition of cysteine in conjunction with UV-vis and EPR spectroscopies. Importantly, complexes with -CH2CF3 tags display good water solubility. Studies with this complex in HeLa cells demonstrate the applicability of these probes to detect cysteine in complex biological environments.
| S-EPMC6242275 | biostudies-literature
Project description:Synthesis, characterization, reactivity, and sensing properties of 4-formylbenzoate complexes of copper(II), zinc(II), and cadmium(II) possessing the 1,10-phenanthroline ancillary ligand are studied. The crystal structures of the (1,10-phenanthroline)bis(4-formylbenzoate)(aqua)copper(II) and (1,10-phenanthroline)bis(4-formylbenzo-ate)zinc(II) and a novel molecular complex comprising an assembly of mononuclear and dinuclear species of (1,10-phenanthroline)bis(4-formylbenzoate)cadmium(II) are reported. These zinc and cadmium complexes are fluorescent; they show differentiable sensitivity to detect three positional isomers of nitroaniline. The mechanism of sensing of nitroanilines by 1,10-phenanthroline and the complexes are studied by fluorescence titrations, photoluminescence decay, and dynamic light scattering. A plausible mechanism showing that 1,10-phenanthroline ligand-based emission quenched by electron transfer from the excited state of 1,10-phenanthroline to nitroaniline is supported by density functional theory calculations. In an anticipation to generate a fluorescent d10-copper(I) formylbenzoate complex by a mild reducing agent such as hydroxylamine hydrochloride for similar sensing of nitroaromatics as that of the d10-zinc and cadmium 4-formylbenzoate complexes, reactivity of d9-copper(II) with hydroxylamine hydrochloride in the presence of 4-formylbenzoic acid and 1,10-phenanthroline is studied. It did not provide the expected copper(I) complex but resulted in stoichiometry-dependent reactions of 4-formylbenzoic acid with hydroxylamine hydrochloride in the presence of copper(II) acetate and 1,10-phenanthroline. Depending on the stoichiometry of reactants, an inclusion complex of bis(1,10-phenanthroline)(chloro)copper(II) chloride with in situ-formed 4-((hydroxyimino)methyl)benzoic acid or copper(II) 4-(hydroxycarbamoyl)benzoate complex was formed. The self-assembly of the inclusion complex has the bis(1,10-phenanthroline)(chloro)copper(II) cation encapsulated in hydrogen-bonded chloride-hydrate assembly with 4-((hydroxyimino)methyl)benzoic acid.
| S-EPMC6844117 | biostudies-literature
Project description:Interest is increasingly focused on the use of transition metal complexes as biochemical, medical, analytical, pharmaceutical, agronomic, anticancer, and antibacterial agents. In this study, three complexes of [Zn(H2L)Cl] (1), [Cu(H2L)(H2O)(NO3)] (2) and [Ni(H2L)(NO3)].2H2O (3) were synthesized from a 2-chloroquinoline-3-carbaldehyde derived ligand [H3L = ((E)-2-(((2-((2-hydroxyethyl)amino)quinolin-3-yl)methylene)amino)ethanol. The compounds were characterized using physicochemical and spectroscopic methods. The results demonstrate that the free ligand behaves as a tridentate ligand with one oxygen and two nitrogen (ONN) donor atoms in 1:1 metal:ligand ratio. The formation constants of the complexes were found to be (K Zn(II) = 2.3 × 106, K Cu(II) = 2.9 × 106, and K Ni(II) = 3.8 × 105). The thermodynamic parameters indicated that the reactions were spontaneous with exothermic nature of metal-ligand interaction energies. Based on the analyses of the experimental (EDX, FTIR, PXRD, MS and TGA) and DFT results, a distorted tetrahedral, a distorted square pyramidal and square planar geometry for Zn(II), Cu(II) and Ni(II) complexes, respectively, were proposed. The B3LYP calculated IR frequencies and TD-B3LYP calculated absorption spectra were found to be in good agreement with the corresponding experimental results. The powder XRD data confirmed that the Zn(II), Cu(II) and Ni(II) complexes have polycrystalline nature with average crystallite sizes of 27.86, 33.54, 37.40 Å, respectively. In vitro antibacterial activity analyses of the complexes were studied with disk diffusion method, in which the complexes showed better activity than the precursor ligand. Particularly the Cu(II) complex showed higher percent activity index (62, 90%), than both Zn(II) (54, 82%) and Ni(II) (41, 68%) complexes against both E. coli and P. aeruginosa, respectively. Using the DPPH assay, the complexes were further assessed for their antioxidant capacities. All metal complexes showed improved antioxidant activity than the free ligand. Zn(II) and Cu(II) complexes, which had IC50 values of 10.46 and 8.62 μg/ml, respectively, showed the best antioxidant activity. The calculated results of Lipinski's rule of five also showed that the target complexes have drug-like molecular nature and similarly, the results of binding mode of action of these compounds against E. coli DNA gyrase B and P. aeruginosa LasR.DNA were found to be in good agreement with the in vitro biological activities.
| S-EPMC9669718 | biostudies-literature
Project description:Three new tripod tetradentate phenolate-amines (H2L1, H2L4 and H2L9), together with seven more already related published ligands, were synthesized, and characterized. With these ligands, two new dinuclear doubly-bridged-phenoxido copper(II) complexes (3, 4), and six more complexes (1, 2, 5-8), a new trinuclear complex (9) with an alternative doubly-bridged-phenoxido and -methoxido, as well as the 1D polymer (10) were synthesized, and their molecular structures were characterized by spectroscopic methods and X-ray single crystal crystallography. The Cu(II) centers in these complexes exhibit distorted square-pyramidal arrangement in 1-4, mixed square pyramidal and square planar in 5, 6, and 9, and distorted octahedral (5+1) arrangements in 7 and 8. The temperature dependence magnetic susceptibility study over the temperature range 2-300 K revealed moderate-relatively strong antiferromagnetic coupling (AF) (|J| = 289-145 cm-1) in complexes 1-6, weak-moderate AF (|J| = 59 cm-1) in the trinuclear complex 9, but weak AF interactions (|J| = 3.6 & 4.6 cm-1) were obtained in 7 and 8. No correlation was found between the exchange coupling J and the geometrical structural parameters of the four-membered Cu2O2 rings.
| S-EPMC10058975 | biostudies-literature
Project description:Ten new compounds of Co, Ni and Cu with glycinamide (HL = glycinamide): [Co(H2O)2(HL)2]Cl2 (1a), [Co(H2O)2(HL)2]Br1.06Cl0.94 (1b), [Co(H2O)2(HL)2]I2 (1c), [Ni(H2O)2(HL)2]Cl2 (2a), [Ni(H2O)2(HL)2]Br0.94Cl1.06 (2b), [Ni(H2O)2(HL)2]I2 (low and room temperature polymorph, 2cLT and 2cRT), [CuCl2(HL)2] (3a), [CuBr1.3Cl0.7(HL)2] (3b) and {[Cu(HL)2]2[Cu2I6]} n (3c), as well as glycinamide hydroiodide (H2LI) and a new polymorph of glycinamide hydrochloride (β-H2LCl) were prepared and characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermal analysis (TG/DTA) and ESR spectroscopy. 1a, 1b, 2a and 2b are isostructural, as well as 1c and 2cRT, while the Cu compounds (3a-c) have entirely different molecular structures. All investigated compounds are mononuclear with exception of the 1D coordination polymer 3c. Compound 3c contains copper ions in the mixed oxidation state Cu(i) and Cu(ii) with interesting magnetic properties. Paramagnetic behaviour was found in 1a, 1b, 3a and 3b. Temperature induced polymorphic transformation was observed in 2c. Compounds 1a and 3a showed moderate antiproliferative activity and selectivity toward the human breast tumor cell line MCF-7.
| S-EPMC9066431 | biostudies-literature