Effect of the coordination of π-acceptor 4-cyanopyridine ligand on the structural and electronic properties ofmeso-tetra(para-methoxy) andmeso-tetra(para-chlorophenyl) porphyrin cobalt(ii) coordination compounds. Application in the catalytic degradation of methylene blue dye

Synthesis, Characterization, X-ray Molecular Structure, Antioxidant, Antifungal, and Allelopathic Activity of a New Isonicotinate-Derived meso-Tetraarylporphyrin

The present article describes the synthesis of an isonicotinate-derived meso-arylporphyrin, that has been fully characterized by spectroscopic methods (including fluorescence spectroscopy), as well as elemental analysis and HR-MS. The structure of an n-hexane monosolvate has been determined by single-crystal X-ray diffraction analysis. The radical scavenging activity of this new porphyrin against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical has been measured. Its antifungal activity against three yeast strains (C. albicans ATCC 90028, C. glabrata ATCC 64677, and C. tropicalis ATCC 64677) has been tested using the disk diffusion and microdilution methods. Whereas the measured antioxidant activity was low, the porphyrin showed moderate but encouraging antifungal activity. Finally, a study of its effect on the germination of lentil seeds revealed interesting allelopathic properties.

Radical Crotylation of Aldehydes with 1,3-Butadiene by Photoredox Cobalt and Titanium Dual Catalysis

Metal-hydride hydrogen atom transfer (MHAT) has been recognized as a powerful method for alkene functionalization; however, photochemical MAT-mediated chemoselective functionalization of dienes remains undeveloped. In this study, we report a radical strategy (1e-) through MHAT using photoredox cobalt and titanium dual catalysis for aldehyde crotylation with butadiene, achieving excellent regio- and diastereoselectivity.

Hydrogen Evolution Reaction, Electrochemical CO2 Reduction, and Oxidative Photodegradation of Organic Dyes Catalyzed by Co(II) Trimethoxy-Meso-Arylporphyrin

In search of robust catalysts for redox transformations such as the hydrogen evolution reaction (HER) or CO2 to CO reduction, we stepped on the previously reported meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato cobalt(II) complex [Co(TTMPP)]. We prepared [Co(TTMPP)] in good yields and characterized it by IR, UV-vis absorption, photoluminescence spectroscopy, and cyclic voltammetry (CV). The [Co(TTMPP)] was used as a homogeneous catalyst for the electrochemical formation of H2 (HER) in DMF (N,N’-dimethylformamide)/TFA (trifluoroacetic acid) and DMF/EtN3BF4 solutions, with high faradic efficiencies (FE). Additionally, the reduction of CO2 to CO in DMF under a CO2 atmosphere was catalyzed in DMF/TFE (TFE = 2,2,2-trifluoroethanol) and DMF/PhOH with high FE and only traces of H2 as a by-product. Turnover frequencies of 15.80 or 9.33 s−1, respectively were determined from CV experiments or controlled potential electrolysis in the presence of 1eq. TFE. They were lower with PhOH as proton source with 13.85 or 8.31 s−1, respectively. Further, [Co(TTMPP)] as a solid catalyst (suspension) allowed the photodecomposition of the organic dyes methylene blue (MB) and rhodamine B (RhB) using H2O2 under visible light irradiation. The photocatalyst was photostable over five cycles. A photocatalytic mechanism was proposed based on trapping experiments of reactive oxygen species.

Synthesis of New Cobalt(III) Meso-Porphyrin Complex, Photochemical, X-ray Diffraction, and Electrical Properties for Photovoltaic Cells

The present work describes the preparation and characterization of a new cobalt(III) porphyrin coordination compound named (chlorido)(nicotinoylchloride)[meso-tetra(para-chlorophenyl)porphyrinato]cobalt(III) dichloromethane monosolvate with the formula [Co^III(TClPP)Cl(NTC)]·CH₂Cl₂ (4). The single-crystal X-ray molecular structure of 4 shows very important ruffling and waving distortions of the porphyrin macrocycle. The Soret and Q absorption bands of 4 are very red-shifted as a consequence of the very distorted porphyrin core. This coordination compound was also studied by fluorescence and cyclic voltammetry. The efficiency of our four porphyrinic compounds-the H₂TClPP (1) free-base porphyrin, the [Co^II(TClPP)] (2) and [Co^III(TClPP)Cl] (3) starting materials, and the new Co(III) metalloporphyrin [Co^III(TClPP)Cl(NTC)]·CH₂Cl₂ (4)-as catalysts in the photochemical degradation was tested on malachite green (MG) dye. The current voltage of complexes 3 and 4 was also studied. Electrical parameters, including the saturation current density (J_s) and barrier height (ϕ_b), were measured.

CO2 to CO Electroreduction, Electrocatalytic H2 Evolution, and Catalytic Degradation of Organic Dyes Using a Co(II) meso-Tetraarylporphyrin

The meso-tetrakis(4-(trifluoromethyl)phenyl)porphyrinato cobalt(II) complex [Co(TMFPP)] was synthesised in 93% yield. The compound was studied by 1H NMR, UV-visible absorption, and photoluminescence spectroscopy. The optical band gap Eg was calculated to 2.15 eV using the Tauc plot method and a semiconducting character is suggested. Cyclic voltammetry showed two fully reversible reduction waves at E1/2 = -0.91 V and E1/2 = -2.05 V vs. SCE and reversible oxidations at 0.30 V and 0.98 V representing both metal-centred (Co(0)/Co(I)/Co(II)/Co(III)) and porphyrin-centred (Por2-/Por-) processes. [Co(TMFPP)] is a very active catalyst for the electrochemical formation of H2 from DMF/acetic acid, with a Faradaic Efficiency (FE) of 85%, and also catalysed the reduction of CO2 to CO with a FE of 90%. Moreover, the two triarylmethane dyes crystal violet and malachite green were decomposed using H2O2 and [Co(TMFPP)] as catalyst with an efficiency of more than 85% in one batch.

Review on Methylene Blue: Its Properties, Uses, Toxicity and Photodegradation

The unavailability of clean drinking water is one of the significant health issues in modern times. Industrial dyes are one of the dominant chemicals that make water unfit for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable and can cause a severe threat to human health and environmental safety. It is usually released in natural water sources, which becomes a health threat to human beings and living organisms. Hence, there is a need to develop an environmentally friendly, efficient technology for removing MB from wastewater. Photodegradation is an advanced oxidation process widely used for MB removal. It has the advantages of complete mineralization of dye into simple and nontoxic species with the potential to decrease the processing cost. This review provides a tutorial basis for the readers working in the dye degradation research area. We not only covered the basic principles of the process but also provided a wide range of previously published work on advanced photocatalytic systems (single-component and multi-component photocatalysts). Our study has focused on critical parameters that can affect the photodegradation rate of MB, such as photocatalyst type and loading, irradiation reaction time, pH of reaction media, initial concentration of dye, radical scavengers and oxidising agents. The photodegradation mechanism, reaction pathways, intermediate products, and final products of MB are also summarized. An overview of the future perspectives to utilize MB at an industrial scale is also provided. This paper identifies strategies for the development of effective MB photodegradation systems.

Copper-based MOF, Cu3(SDBA)2(HSDBA), as a catalyst for efficient reduction of 4-nitrophenol in the presence of sodium borohydride

Herein, we report the synthesis of the copper-based MOF, Cu3(SDBA)2(HSDBA), using a solvothermal method.

Bio-multifunctional noncovalent porphyrin functionalized carbon-based nanocomposite

Herein, in a one-pot method, the reduced graphene oxide layers with the assistance of multiwalled carbon nanotubes were decorated to provide a suitable space for the in situ growth of CoNi₂S₄, and the porphyrins were incorporated into the layers as well to increase the sensitivity of the prepared nanostructure. The prepared nanocomposite can establish π-π interactions between the genetic material and on the surface of porphyrin rings. Also, hydrogen bonds between genetic domains and the porphyrin' nitrogen and the surface hydroxyl groups are probable. Furthermore, the potential donor-acceptor relationship between the d⁷ transition metal, cobalt, and the genetic material provides a suitable way to increase the interaction and gene loading , and transfections. The reason for this phenomenon was optimized to increase the EGFP by up to 17.9%. Furthermore, the sensing ability of the nanocomposite towards H₂O₂ was investigated. In this regard, the limit of detection of the H₂O₂ obtained 10 µM. Also, the in situ biosensing ability in the HEK-293 and PC12 cell lines was evaluated by the addition of PMA. The nanocomposite showed the ability to detect the released H₂O₂ after adding the minimum amount of 120 ng/mL of the PMA.

An experimental and theoretical exploration of supramolecular interactions and photoresponse properties of two Ni(ii) complexes

Two new nickel(ii) complexes, C₃₂H₂N₈NiClO₉ (1) and C₃₆H₂₈N₁₂NiOF₂₄P₄ (2) are reported. The noncovalent interactions witnessed in their crystal packing have been analysed using DFT calculations.

A new cobalt(ii) meso-porphyrin: synthesis, characterization, electric properties and application in the catalytic degradation of dyes

In this work, a new porphyrin, 5,10,15,20-tetrakis{4-[((4-methoxyphenyl)acetyl)oxy]phenyl}porphyrin (H₂TMAPP) (1), and its cobalt complex [Co^II(TMAPP)] (2) were synthesized in good and quantitative yields, respectively. The chemical structures of these synthesized compounds were confirmed by FT-IR, ¹H NMR, MS, UV-visible, and fluorescence spectroscopy. Their photophysical properties, namely their molar extinction coefficients (∑), fluorescence quantum yields (Φ_f) and lifetimes (τ_f), were determined and compared with those of meso-tetraphenylporphyrin. Furthermore, their electrochemical behaviours were examined using cyclic voltammetry (CV). Dielectric properties such as the conductivity (σ) and the real (M′) and imaginary (M′′) parts of the dielectric modulus were investigated as a function of temperature and frequency. The impedance analysis was carried out using Cole–Cole plots to elucidate the electrical conduction mechanism. The catalytic power and the adsorption properties of the prepared compounds were studied for methylene blue (MB) and crystal violet (CV) degradation. The results reveal that the studied compound [Co^II(TMAPP)] can be used as a catalyst for the decolourisation of dyes in the presence of H₂O₂.

In this work, a new porphyrin, 5,10,15,20-tetrakis{4-[((4-methoxyphenyl)acetyl)oxy]phenyl}porphyrin (H₂TMAPP) (1), and its cobalt complex [Co^II(TMAPP)] (2) were synthesized in good and quantitative yields, respectively.

Zinc(ii) triazole meso-arylsubstituted porphyrins for UV-visible chloride and bromide detection. Adsorption and catalytic degradation of malachite green dye

Three new triazole meso-arylporphyrins (4a-c) were synthesized by the copper(i)-catalyzed azide alkyne cycloaddition (CuAAC) "click" reaction in high yield. The corresponding zinc(ii) coordination compounds (5a-c) have also been prepared. All 4a-c and 5a-c porphyrin species were fully characterized by elemental analysis, electrospray ionization and MALDI-TOF mass spectrometry, infrared spectroscopy, proton nuclear magnetic resonance, UV-visible, fluorescence and cyclic voltammetry. The zinc(ii) 5a-c complexes have been tested as detectors for Cl- and Br- anions. UV-visible titrations reveal that these host systems exhibit strong anion binding affinities. The efficiency of the adsorption of the malachite green dye (MG) dye on the 4a-c free base porphyrins and the corresponding zinc(ii) complexes 5a-c was investigated by a kinetic study using these synthetic porphyrin derivatives as adsorbents. The use of our triazole Zn(ii) complexes in the catalytic degradation of the MG dye is the first example where a metalloporphyrin is involved in the MG dye decolorization reaction. The degradation reactions were carried out using an ecological oxidant (H2O2), where the efficiency of the decolorization has been characterized by UV-visible spectroscopic analysis. Several factors affecting the degradation phenomenon have been studied. The energetic parameters concerning the degradation process have also been determined.