Synthesis and structural characterization of new heteroleptic copper(I) complexes based on mixed phosphine/thiocarbamoyl-pyrazoline ligands

Favarin, Lis Regiane Vizolli; Rosa, Persiely Pires; Pizzuti, Lucas; Machulek, Amílcar; Caires, Anderson R. L.; Bezerra, Leticia S.; Pinto, Leandro Moreira de Campos; Maia, Gilberto; Gatto, Claudia C.; Back, Davi F.; Anjos, Ademir dos

doi:10.1016/j.poly.2016.10.003

Cited by 23 publications

(5 citation statements)

References 29 publications

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“…A similar shift was also seen in the signals of ν(C−O) between the ligands and complexes, indicating the coordination of phenol oxygen to the copper. These observations were consistent with other published works involving copper complexes [ 19 , 23 , 24 , 25 , 26 ]. The signals observed around 460 and 410 cm −1 in the spectra were assigned to the stretching frequencies of the copper-donor atom-chelating ligand, ν(Cu−O) and ν(Cu−N), respectively.…”

Section: Resultssupporting

confidence: 94%

Efficient Catalytic Reduction of 4-Nitrophenol Using Copper(II) Complexes with N,O-Chelating Schiff Base Ligands

et al. 2021

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The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride was used as a model to test the catalytic activity of copper(II) complexes containing N,O-chelating Schiff base ligands. In this study, a series of copper(II) complexes containing respective Schiff base ligands, N′-salicylidene-2-aminophenol (1), N′-salicylidene-2-aminothiazole (2), and N,N′-bis(salicylidene)-o-phenylenediamine (3), were synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR), and UV-Visible (UV-Vis) and electron paramagnetic resonance (EPR) spectroscopies. The results from the 4-nitrophenol reduction showed that 3 has the highest catalytic activities with 97.5% conversion, followed by 2 and 1 with 95.2% and 90.8% conversions, respectively. The optimization of the catalyst amount revealed that 1.0 mol% of the catalyst was the most optimized amount with the highest conversion compared to the other doses, 0.5 mol% and 1.5 mol%. Recyclability and reproducibility tests confirmed that all three complexes were active, efficient, and possess excellent reproducibility with consistent catalytic performances and could be used again without a major decrease in the catalytic activity.

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Section: Resultssupporting

confidence: 94%

Efficient Catalytic Reduction of 4-Nitrophenol Using Copper(II) Complexes with N,O-Chelating Schiff Base Ligands

et al. 2021

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“…The reduction processes for compounds 1 − 5 were poorly resolved, while 6 demonstrates reversible reduction at a potential of −1.7 V. Due to the irreversibility of the oxidation processes, differential pulse voltammetry (DPV) ( Figure S19 ) was used to determine the precise values of the oxidation potentials, and further DPV data will be analyzed. The first oxidation potentials,

(1) ( Table 1 ), for compounds 1 − 4 and 6 are close to 0.8 V vs. Fc/Fc + , while the voltammogram of the oxidation of compound 5 contains a less pronounced peak at 0.72 V. It indicates that the metal-centred oxidation processes of complexes 1 − 6 are similar to each other and the Cu + /Cu 2+ transition potential is close to that observed in similar complexes (0.8 V vs. Fc/Fc + ) [ 23 , 24 , 25 , 26 , 27 , 29 , 30 , 35 , 37 , 45 , 46 , 47 ]. The low intensity of the first oxidation peak in the complex 5 indicates that metal oxidation is suppressed, possibly, due to sterical reasons.…”

Section: Resultsmentioning

confidence: 67%

The Tail Wags the Dog: The Far Periphery of the Coordination Environment Manipulates the Photophysical Properties of Heteroleptic Cu(I) Complexes

et al. 2022

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In this work we show, using the example of a series of [Cu(Xantphos)(N^N)]+ complexes (N^N being substituted 5-phenyl-bipyridine) with different peripheral N^N ligands, that substituents distant from the main action zone can have a significant effect on the physicochemical properties of the system. By using the C≡C bond on the periphery of the coordination environment, three hybrid molecular systems with −Si(CH3)3, −Au(PR3), and −C2HN3(CH2)C10H7 fragments were produced. The Cu(I) complexes thus obtained demonstrate complicated emission behaviour, which was investigated by spectroscopic, electrochemical, and computational methods in order to understand the mechanism of energy transfer. It was found that the −Si(CH3)3 fragment connected to the peripheral C≡C bond changes luminescence to long-lived intra-ligand phosphorescence, in contrast to MLCT phosphorescence or TADF. The obtained results can be used for the design of new materials based on Cu(I) complexes with controlled optoelectronic properties on the molecular level, as well as for the production of hybrid systems.

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“…The preparation of the promising complexes was performed including a modification in the synthetic protocols already published in the literature [ 22 , 23 ]. Reactions of copper(II) chloride, 2,2′-bipyridine, and the thiouracil linkers at 1:1:1 molar ratios in MeOH/THF medium resulted in two promising coordination complexes with the compositions [CuCl 2 (Bipy)(L 1 )], wherein L 1 = 2-Thiouracil; and [CuCl 2 (Bipy)(L 2 )], wherein L 2 = 6-methyl-2-thiouracil.…”

Section: Resultsmentioning

confidence: 99%

“…320 nm in the UV-Vis spectra of the complexes. It is related to the appearance of LMCT (ligand to metal charge transfer) electronic transitions which should be present after complexation of ligands in transition metals [ 23 ]. The π → π* electronic transitions related to the bipyridine coligand and aromatic system of the thiouracile ring that appeared centered at ca.…”

Section: Resultsmentioning

confidence: 99%

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A Promising Copper(II) Complex as Antifungal and Antibiofilm Drug against Yeast Infection

et al. 2018

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The high mortality rate of candidemia and the limited option for the treatment of Candida spp. infection have been driving the search for new molecules with antifungal property. In this context, coordination complexes of metal ions and ligands appear to be important. Therefore, this study aimed to synthesize two new copper(II) complexes with 2-thiouracil and 6-methyl-2-thiouracil ligands and to evaluate their mutagenic potential and antifungal activity against Candida. The complexes were synthesized and characterized by infrared vibrational spectroscopy, CHN elemental analysis, UV-Vis experiments and ESI-HRMS spectrometry studies. The antifungal activity was evaluated by broth microdilution against 21 clinical isolates of Candida species. The mutagenic potential was evaluated by the Ames test. The complexes were Cu(Bipy)Cl2(thiouracil) (Complex 1) and Cu(Bipy)Cl2(6-methylthiouracil) (Complex 2). Complex 1 showed fungicidal and fungistatic activities against all isolates. Furthermore, the Minimum Inhibitory Concentration (MIC) from 31 to 125 µg/mL and inhibition percentage of 9.9% against the biofilms of C. krusei and C. glabrata were demonstrated. At the concentrations tested, complex 1 exhibited no mutagenic potential. Complex 2 and the free ligands exhibited no antifungal activity at the concentrations evaluated. Since complex 1 presented antifungal activity against all the tested isolates and no mutagenic potential, it could be proposed as a potential new drug for anti-Candida therapy.

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Synthesis and structural characterization of new heteroleptic copper(I) complexes based on mixed phosphine/thiocarbamoyl-pyrazoline ligands

Cited by 23 publications

References 29 publications

Efficient Catalytic Reduction of 4-Nitrophenol Using Copper(II) Complexes with N,O-Chelating Schiff Base Ligands

Efficient Catalytic Reduction of 4-Nitrophenol Using Copper(II) Complexes with N,O-Chelating Schiff Base Ligands

The Tail Wags the Dog: The Far Periphery of the Coordination Environment Manipulates the Photophysical Properties of Heteroleptic Cu(I) Complexes

A Promising Copper(II) Complex as Antifungal and Antibiofilm Drug against Yeast Infection

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