Two diphosphanes with variable-length ligands tested as nucleophiles to prepare isoporphyrin copolymers in the presence of ditolylporphyrin of zinc (ZnT2P) prevented the oxidation of the diphosphine ligand. This paper demonstrates the power of this approach and describes the photoelectrocatalytic properties. The obtained copolymers were characterized by UV-vis spectroscopy, X-ray photoelectron spectroscopy, atomic force micrograph (AFM), EQCM (Electrochemical Quartz Cristal Microbalance) and electrochemistry. Their impedance properties (EIS) were studied and their photovoltaic performances were also investigated by photocurrent transient measurements under visible light irradiation.

Positively charged phosphorus-containing heterocycles are characteristic core skeletons for functional molecules. While various phosphonium-containing five- or six-membered-ring compounds have been reported, the seven-membered-ring phosphepinium have not been fully studied yet. In this study, dithieno[3,2-b; 2\',3\'-f]phosphepinium ions containing electron-donating aminophenyl groups were synthesized. An X-ray crystallographic analysis of the resulting donor-acceptor-donor dyes revealed a bent conformation of the central seven-membered ring. These compounds exhibit fluorescence in the near-infrared region with a bathochromic shift of ca. 70 nm compared to a phosphepine oxide congener and a large Stokes shift. High fluorescence quantum yields were obtained even in polar solvents due to the suppression of the nonradiative decay process. A theoretical study revealed that the phosphepinium skeleton is highly electron-accepting owing to the orbital interaction between a px orbital of the phosphonium moiety and a π* orbital of the 1,3,5-hexatriene moiety. Due to the lower-lying px orbital in the phosphonium moiety compared to that of the phosphine oxide and the bent conformation of the seven-membered ring, the phosphepinium ring permits effective px-π* conjugation. A large structural relaxation with a contribution of a quinoidal resonance structure is suggested in the excited state, which should be responsible for the bright emission with a large Stokes shift.

Mitochondria-targeted antioxidants (MTAs) have been studied quite intensively in recent years as potential therapeutic agents and vectors for the delivery of other active substances to mitochondria and bacteria. Their most studied representatives are MitoQ and SkQ1, with its fluorescent rhodamine analog SkQR1, a decyl ester of rhodamine 19 carrying plastoquinone. In the present work, we observed a pronounced antibacterial action of SkQR1 against Gram-positive bacteria, but virtually no effect on Gram-negative bacteria. The MDR pump AcrAB-TolC, known to expel SkQ1, did not recognize and did not pump out SkQR1 and dodecyl ester of rhodamine 19 (C12R1). Rhodamine 19 butyl (C4R1) and ethyl (C2R1) esters more effectively suppressed the growth of ΔtolC Escherichia coli, but lost their potency with the wild-type E. coli pumping them out. The mechanism of the antibacterial action of SkQR1 may differ from that of SkQ1. The rhodamine derivatives also proved to be effective antibacterial agents against various Gram-positive species, including Staphylococcus aureus and Mycobacterium smegmatis. By using fluorescence correlation spectroscopy and fluorescence microscopy, SkQR1 was shown to accumulate in the bacterial membrane. Thus, the presentation of SkQR1 as a fluorescent analogue of SkQ1 and its use for visualization should be performed with caution.

Quantum dots (QDs) with metal fluoride surface ligands were prepared via reaction with anhydrous oleylammonium fluoride. Carboxylate terminated II-VI QDs underwent carboxylate for fluoride exchange, while InP QDs underwent photochemical acidolysis yielding oleylamine, PH3, and InF3. The final photoluminescence quantum yield (PLQY) reached 83% for InP and near unity for core-shell QDs. Core-only CdS QDs showed dramatic improvements in PLQY, but only after exposure to air. Following etching, the InP QDs were bound by oleylamine ligands that were characterized by the frequency and breadth of the corresponding ν(N-H) bands in the infrared absorption spectrum. The fluoride content (1.6-9.2 nm-2) was measured by titration with chlorotrimethylsilane and compared with the oleylamine content (2.3-5.1 nm-2) supporting the formation of densely covered surfaces. The influence of metal fluoride adsorption on the air stability of QDs is discussed.

We have developed a catalytic protocol for Diels-Alder reaction using trialkylphosphonium oxoborates as oxyanion hole catalysts. The reaction can be operated under ambient conditions. Dienes could easily polymerize under acidic condition. Nonetheless, these acid-sensitive substrates are compatible with the catalytic protocol and the reaction scope covers a wide range of substrates.

Clinically manifested resistance of bacteria to antibiotics has emerged as a global threat to society and there is an urgent need for the development of novel classes of antibacterial agents. Recently, the use of phosphorus in antibacterial agents has been explored in quite an unprecedent manner. In this comprehensive review, we summarize the use of phosphorus-containing moieties (phosphonates, phosphonamidates, phosphonopeptides, phosphates, phosphoramidates, phosphinates, phosphine oxides, and phosphoniums) in compounds with antibacterial effect, including their use as β-lactamase inhibitors and antibacterial disinfectants. We show that phosphorus-containing moieties can serve as novel pharmacophores, bioisosteres, and prodrugs to modify pharmacodynamic and pharmacokinetic properties. We further discuss the mechanisms of action, biological activities, clinical use and highlight possible future prospects.

Dendrite growth on electrode-electrolyte interphase has severely limited applications of lithium metal batteries (LMBs). Here, we developed an ionic alternating polymer with fluorocarbons and phosphonium cations in repeating units to regulate Li deposition for the first time. The combined functionalities in the F/P hybrid polymer exhibit remarkable characteristics as a protective layer on top of Li anode, demonstrating outstanding electrochemical stability, ion flux redistributing capability and adaptive chain mobility. Based on characterizations and simulations, this cationic interlayer could effectively furnish long-standing electrostatic shielding for anodes, allowing restrained coating decomposition and homogenized electric field distribution to induce dendrite-free Li deposition, and enabling full cells with enhanced rate and long-term cycling performance. Given the importance of LMBs, this work will promote polymer design to stabilize anodes with superior electrochemical behavior.

Phosphorous is an essential element for the life of organisms, and phosphorus-based compounds have many uses in industry, such as flame retardancy reagents, ingredients in fertilizers, pyrotechnics, etc. Ionic liquids are salts with melting points lower than the boiling point of water. The term \"polymerized ionic liquids\" (PILs) refers to a class of polyelectrolytes that contain an ionic liquid (IL) species in each monomer repeating unit and are connected by a polymeric backbone to form macromolecular structures. PILs provide a new class of polymeric materials by combining some of the distinctive qualities of ILs in the polymer chain. Ionic liquids have been identified as attractive prospects for a variety of applications due to the high stability (thermal, chemical, and electrochemical) and high mobility of their ions, but their practical applicability is constrained because they lack the benefits of both liquids and solids, suffering from both leakage issues and excessive viscosity. PILs are garnering for developing non-volatile and non-flammable solid electrolytes. In this paper, we provide a brief review of phosphonium-based PILs, including their synthesis route, properties, advantages and drawbacks, and the comparison between nitrogen-based and phosphonium-based PILs. As phosphonium PILs can be used as polymer electrolytes in lithium-ion battery (LIB) applications, the conductivity and the thermo-mechanical properties are the most important features for this polymer electrolyte system. The chemical structure of phosphonium-based PILs that was reported in previous literature has been reviewed and summarized in this article. Generally, the phosphonium PILs that have more flexible backbones exhibit better conductivity values compared to the PILs that consist of a rigid backbone. At the end of this section, future directions for research regarding PILs are discussed, including the use of recyclable phosphorus from waste.

The aim of this work is to investigate the efficiency of a phosphonium-based strong anion exchange sorbent for the extraction of some selected phenolic acids. The material was synthesized through chloromethylation of a porous poly(styrene-divinylbenzene) substrate with high degree of crosslinking, followed by quaternarization with tributyl phosphine. The parameters affecting the solid phase extraction of five phenolic acids, namely chlorogenic acid, caffeic acid, dihydroxybenzoic acid, ferulic acid and rosmarinic acid were optimized. The sample pH and the type, volume and concentration of the eluting solutions were investigated. The analysis of the phenolic acids after extraction was performed using HPLC with diode array detection. Limit of detection, limit of quantitation, linear range, correlation coefficient and reproducibility for the determination of the phenolic acids were estimated. The retention of the phenolic acids on the developed phase was studied using breakthrough analysis. The experimental breakthrough curves were fitted by Boltzmann\'s function, and the regression parameters were utilized for the determination of the breakthrough parameters. The results obtained using the developed phase were compared with those obtained by the commercially available Oasis MAX sorbent. The proposed approach was successfully applied for the extraction and pre-concentration of rosmarinic acid from rosemary leaf (Rosmarini folium) alcoholic extract.

The search for new antibiotics, substances that kill prokaryotic cells and do not kill eukaryotic cells, is an urgent need for modern medicine. Among the most promising are derivatives of triphenylphosphonium, which can protect the infected organs of mammals and heal damaged cells as mitochondria-targeted antioxidants. In addition to the antioxidant action, triphenylphosphonium derivatives exhibit antibacterial activity. It has recently been reported that triphenylphosphonium derivatives cause either cytotoxic effects or inhibition of cellular metabolism at submicromolar concentrations. In this work, we analyzed the MTT data using microscopy and compared them with data on changes in the luminescence of bacteria. We have shown that, at submicromolar concentrations, only metabolism is inhibited, while an increase in alkyltriphenylphosphonium (CnTPP) concentration leads to adhesion alteration. Thus, our data on eukaryotic and prokaryotic cells confirm a decrease in the metabolic activity of cells by CnTPPs but do not confirm a cytocidal effect of TPPs at submicromolar concentrations. This allows us to consider CnTPP as a non-toxic antibacterial drug at low concentrations and a relatively safe vector for delivering other antibacterial substances into bacterial cells.