Peracetic acid activated by nickel cobaltite as effective oxidizing agent for BPA and its analogues degradation.

The presented research concerns the use of nickel cobaltite nanoparticles (NiCo2O4 NPs) for the heterogeneous activation of peracetic acid and application of NiCo2O4-PAA system for degradation 10 organic micropollutants from the group of bisphenols. The bisphenols removal (initial concentration 1 µM) process was optimized by selecting the appropriate process conditions. The optimal amount of catalyst (115 mg/L), peracetic acid (PAA) concentration (7 mM) and pH (7) were determined using response surface analysis in the Design of Experiment. Then, NiCo2O4 NPs were used to check the possibility of reuse in subsequent oxidation cycles. The work also attempts to explain the mechanism of oxidation of the studied micropollutants. The participation of the sorption process on the catalyst was excluded and based on the experiments with radical scavengers it can be concluded that the oxidation proceeds in a radical pathway, mainly with participation of O2•- radicals. Experiments conducted in real water matrices exhibit low impact on degradation efficiency. Toxicity tests with green alga Acutodesmus obliquus and aquatic plant Lemna minor showed that post-reaction mixture influenced growth and the content of photosynthetic pigments in concentration dependent manner.

Synthesis, Post-Functionalization and Properties of Diphosphapentaarenes.

Linearly-fused polyarenes are an important class of compounds with high relevance in materials science. While modifying the shape and size represents a common means to fine-tune their properties, the precise placement of heteroatoms is a strategy that is receiving an increasing deal of attention to overcome the intrinsic limitations of all-carbon structures. Thus, linearly-fused diphosphaarenes recently emerged as a novel family of molecules with striking optoelectronic properties and outstanding stability. However, the properties of diphosphaarenes are far from being benchmarked. Herein, we report the synthesis, phosphorus post-functionalization and properties of new diphosphapentaarene derivatives. We describe their synthetic limitations and unveil their potential for optoelectronic applications.

Luminescent Pyrrole-Based Phosphaphenalene Gold Complexes: Versatile Anticancer Tools with Wide Applicability.

Invited for the cover of this issue are the groups of Christel Herold-Mende and Carlos Romero-Nieto at the Universities of Heidelberg and Castilla-La Mancha. The image depicts the use of phosphaphenalene gold(I) complexes for the treatment of brain cancer. Read the full text of the article at 10.1002/chem.202104535.

Luminescent Pyrrole-Based Phosphaphenalene Gold Complexes: Versatile Anticancer Tools with Wide Applicability.

Brain cancer, one of the most lethal diseases, urgently requires the discovery of novel theranostic agents. In this context, molecules based on six-membered phosphorus heterocycles - phosphaphenalenes - are especially attractive; they possess unique characteristics that allow precise chemical engineering. Herein, we demonstrate that subtle structural modifications of the phosphaphenalene-based gold(I) complexes lead to modify their electronic distribution, endow them with marked photophysical properties and enhance their efficacy against cancer. In particular, phosphaphenalene-based gold(I) complexes containing a pyrrole ring show antiproliferative properties in 14 cell lines including glioblastomas, brain metastases, meningiomas, IDH-mutant gliomas and head and neck cancers, reaching IC50 values as low as 0.73 µM. The bioactivity of this new family of drugs in combination with their photophysical properties thus offer new research possibilities for both the fundamental investigation and treatment of brain cancer.

Controlling the molecular arrangement of racemates through weak interactions: the synergy between π-interactions and halogen bonds.

POX and NX halogen bonds in combination with π-stacking interactions lead to the sorting of π-extended R- and S-isomers. Theoretical calculations point to a positive synergistic effect between the π-interactions and the halogen bonds to be the origin of such phenomena. As a result, enantiomeric building blocks form homoleptically connected quadrangular structures.

Nanostructural catalyst: metallophthalocyanine and carbon nano-onion with enhanced visible-light photocatalytic activity towards organic pollutants.

Metallophthalocyanine (MPc) and carbon nano-onion (CNO) derivatives were synthesized and characterized by using ultraviolet-visible spectroscopy, infrared and Raman spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy and X-ray powder diffraction. The unmodified CNOs and MPc-CNO derivatives were used as photocatalysts for rhodamine B (RhB) degradation under visible-light irradiation. The photocatalytic studies revealed that the MPc-CNO nanostructural materials simultaneously exhibited a high absorption capacity and an excellent visible-light-driven photocatalytic activity towards RhB. These nanostructures possess great potential for use as active photocatalysts for organic pollutant degradation.

Extraction of 2'-O-apiosyl-6'-O-crotonic acid-betanin from the ayrampo seed (Opuntia soehrensii) cuticle and its use as an emitting layer in an organic light-emitting diode.

The molecule 2'-O-apiosyl-6'-O-crotonic acid-betanin (called Achkiy) was obtained after an ecofriendly and low-cost purification process of the extract from the ayrampo seed cuticle. Results from EDS give us an idea of the organic elements present in the ayrampo cuticle layer composed of carbon, oxygen and nitrogen. Further characterization analysis of ayrampo extract by Fourier Transform Infrared Spectrophotometry (FTIR) corroborated the presence of characteristic functional groups corresponding to carboxyl, carbonyls, hydroxyls and secondary amines. On the other hand, we have confirmed by absortion peak the glucose, apiosyl, crotonic acid and betanin at 227 nm, 276 nm, 291 nm and 534 nm bands respectively. Mass Spectrometry (MS) characterization was used finally to identify the electroactive Achkiy molecule. This molecule was tested in an Organic Light Emitting Diode (OLED) achieving a luminance of 4.8 Cd m-2 when bias voltage of 16.5 V and a current of 34.1 mA was applied. In addition, the irradiance generated by the Achkiy layer reaches a value of ≈ 113.3 µW m-2 emitting light with a λ ≈ 390.10 nm. These preliminary results report an interesting molecule extracted from a natural pigment wich emits light in the blue region.

Synthesis of Blue-Luminescent Seven-Membered Phosphorus Heterocycles.

A facile synthetic procedure to prepare π-extended seven-membered phosphorus heterocycles, both symmetric and asymmetric, is reported. The prepared molecules present a persistent nonplanar framework and are soluble in a wide variety of solvents. The seven-membered phosphorus heterocycles can be electrochemically reduced and oxidized, and photoluminesce with a blue color.

Organophosphorus-B(C6F5)3 adducts: towards new solid-state emitting materials.

The coordination of B(C6F5)3 to materials based on six-membered phosphorus heterocycles via P[double bond, length as m-dash]O bonds tunes their physicochemical properties both in solution and in the solid state, remarkably improving their performances in light-emitting layers.

Zinc Porphyrin-Functionalized Fullerenes for the Sensitization of Titania as a Visible-Light Active Photocatalyst: River Waters and Wastewaters Remediation.

Zinc porphyrin-functionalized fullerene [C60] derivatives have been synthesized and used to prepare titania-based composites. The electrochemical properties and HOMO and LUMO levels of the photosensitizers were determined by electrochemical measurements. Raman and IR techniques were used to study chemical groups present on the titania surface. Absorption properties of the composites were measured in the solid state by diffuse reflectance UV-Vis spectra (DRS). The zeta potential and aggregate sizes were determined using dynamic light scattering (DLS) and electrophoretic light scattering (ELS) techniques. Surface areas were estimated based on Brunauer⁻Emmett⁻Teller (BET) isotherms. The photocatalytic activity of the photocatalysts was tested using two model pollutants, phenol and methylene blue. The composite with the highest photocatalytic potential (1/TiO2) was used for river and wastewater remediation. The photodegradation intermediates were identified by LC-UV/Vis-MS/MS techniques.

Carbon nanoonion-ferrocene conjugates as acceptors in organic photovoltaic devices.

Many macromolecular systems, including carbon nanostructures (CNs), have been synthesized and investigated as acceptors in photovoltaic devices. Some CNs have shown interesting electrochemical, photophysical and electrocatalytic properties and have been used in energy and sustainability applications. This study focuses on the covalent functionalization of carbon nanoonion (CNO) surfaces with ferrocene moieties to obtain donor-acceptor systems involving CNOs as acceptors. The systems were synthesized and characterized by infrared, Raman, UV-vis and fluorescence spectroscopies, thermogravimetric analysis, scanning electron microscopy, nitrogen adsorption and electrochemical measurements. The HOMO-LUMO levels were calculated to evaluate the possibility of using these systems in photoactive devices. In this study, for the first time, the CNO-based derivatives were applied as acceptors in the active layer of photovoltaic devices. This study is the first to use large CNO-based derivatives as acceptors in organic photovoltaic devices, and a power conversion efficiency as high as 1.89% was achieved.

Highlights on π-systems based on six-membered phosphorus heterocycles.

π-Extended molecules based on six-membered phosphorus heterocycles are exceptional systems due to their unique structural and chemical properties. Even though the first six-membered phosphorus heterocycles were synthesized in the 1950s-1960s, their chemistry is currently experiencing a renaissance with the focus on materials science. In this perspective, we highlight relevant systems that emphasize the potential of these particular organophosphorus materials for different fields of research, from bio- to optoelectronic applications. We also discuss their properties and outline our personal outlook on the future efforts toward the next generation of improved organophosphorus materials.

Influence of the Synthetic Conditions on the Structural and Electrochemical Properties of Carbon Nano-Onions.

Thermal annealing of nanodiamonds with diameters of a few nanometers (in an inert atmosphere and at temperatures in the range: 1500-1800 °C) leads to the formation of carbon nano-onions (CNOs) with diameters between 5 and 6 nm, which correspond to nanostructures with six to eight graphitic layers. The resulting spherical CNO structures were thermally modified under different atmospheres and characterized by SEM, TEM, thermogravimetric analysis and spectroscopic (Raman and diffuse reflectance infrared Fourier transform/FTIR) spectroscopy. The electrochemical properties of the CNOs prepared under different conditions were determined and compared. The results reveal that the CNOs show different structures with predominant spherical "small" carbon nano-onions. The aim of this article is to investigate the impact of the CNO's synthesis conditions on the resulting structures and study the effect of further thermal modifications on the sizes, shapes and homogeneity of these carbon nanostructures.

Tuning the reorganization energy of electron transfer in supramolecular ensembles--metalloporphyrin, oligophenylenevinylenes, and fullerene--and the impact on electron transfer kinetics.

Oligo(p-phenylenevinylene) (oPPV) wires of various lengths featuring pyridyls at one terminal and C60 moieties at the other, have been used as molecular building blocks in combination with porphyrins to construct a novel class of electron donor-acceptor architectures. These architectures, which are based on non-covalent, directional interactions between the zinc centers of the porphyrins and the pyridyls, have been characterized by nuclear magnetic resonance spectroscopy and mass spectrometry. Complementary physico-chemical assays focused on the interactions between electron donors and acceptors in the ground and excited states. No appreciable electron interactions were noted in the ground state, which was being probed by electrochemistry, absorption spectroscopy, etc.; the electron acceptors are sufficiently decoupled from the electron donors. In the excited state, a different picture evolved. In particular, steady-state and time-resolved fluorescence and transient absorption measurements revealed substantial electron donor-acceptor interactions. These led, upon photoexcitation of the porphyrins, to tunable intramolecular electron-transfer processes, that is, the oxidation of porphyrin and the reduction of C60. In this regard, the largest impact stems from a rather strong distance dependence of the total reorganization energy in stark contrast to the distance independence seen for covalently linked conjugates.

Investigation of novel material for effective photodegradation of bezafibrate in aqueous samples.

A novel composite with an enhanced photocatalytic activity was prepared and applied to study the removal of bezafibrate (BZF), a hypolypemic pharmaceutical, from an aqueous environment. For the enhancement of titanium dioxide photoactivity a fullerene derivative, 2-(ferrocenyl) fulleropyrrolidine (FcC60), was synthesized and applied. Obtained composite was found to show a higher catalytic activity than pristine TiO2. Therefore, high hopes are set in composites that are based on carbonaceous nanomaterials and TiO2 as a new efficient photocatalysts.

Surface plasmon resonance imaging biosensor for cathepsin G based on a potent inhibitor: development and applications.

A specific surface plasmon resonance imaging (SPRI) array biosensor for the determination of the enzymatically active cathepsin G (CatG) has been developed. For this purpose, a specific interaction between an inhibitor immobilized onto a chip surface and CatG in an analyzed solution was used. The MARS-115 CatG peptidyl inhibitor containing the 1-aminoalkylphosphonate diaryl ester moiety at the C terminus and N-succinamide with a free carboxylic function was synthesized and covalently immobilized onto the gold chip surface via the thiol group (cysteamine). Atomic force microscopy was used for the observation of surface changes during the subsequent steps of chip manufacture. Optimal detection conditions were chosen. High specificity of synthesized inhibitor to CatG was proved. The precision, as well as the accuracy, was found to be well suited to enzyme determination. The sensor application for the determination of CatG in white blood cells and saliva was shown for potential diagnosis of leukemia and oral cavity diseases during the early stages of those pathological states.

Development of an SPR imaging biosensor for determination of cathepsin G in saliva and white blood cells.

Cathepsin G (CatG) is an endopeptidase that is associated with the early immune response. The synthetic compound cathepsin G inhibitor I (CGI-I) was tested for its ability to inhibit the activity of CatG via a new surface plasmon resonance imaging assay. CGI-I was immobilized on the gold surface of an SPR sensor that was first modified with 1-octadecanethiol. A concentration of CGI-I equal to 4.0 µg·mL-1 and a pH of 8.0 were found to give the best results. The dynamic response of the sensor ranges from 0.25 to 1.5 ng·mL-1, and the detection limit is 0.12 ng·mL-1. The sensor was applied to detect CatG in human saliva and white blood cells.FigureThe synthetic compound cathepsin G inhibitor I (CGI-I) was tested for its ability to inhibit the activity of cathepsin G via a newly developed surface plasmon resonance imaging assay. The sensor was applied to detect cathepsin G in human saliva and white blood cells.

SPR imaging biosensor for aspartyl cathepsins: sensor development and application for biological material.

A Surface Plasmon Resonance Imaging (SPRI) sensor has been developed for highly selective determination of cathepsin D (Cat D) or/and E (Cat E). The sensor contains immobilised pepstatin A, which binds aspartyl proteases from solution. Pepstatin A activated with N-Hydroxysuccinimide (NHS) and N-Ethyl-N'-(3-dimethylaminopropyl) carbodiimide (EDC) was immobilized on an amine-modified gold surface. Cysteamine was used for modification of the gold surface. Pepstatin A concentration and pH of interaction were optimised. A concentration of pepstatin equal to 0.5 microg mL(-1) and a pH of 3.75 were selected as optimal. The sensor's dynamic response range is between 0.25 and 1.0 ng mL(-1), and the detection limit is 0.12 ng mL(-1). However, the sensor cannot distinguish between Cat D and Cat E. In order to demonstrate the sensor's potential, Cat E was determined in human red blood cells, Cat D in human saliva, as well as total concentration of Cat D and Cat E in human nasal polyps.