Australian Journal of Chemistry最新文献

Endotracheal intubation holds significant importance in trauma point care and emergency medicine. However, laryngeal injury and subsequent chronic complications can result from the friction between the mucosa and the tube during intubation. Here we present a lubricant coating based on hyaluronic acid. Inspired by mussels, hyaluronic acid was first conjugated with dopamine to obtain HD, and then a triblock copolymer Pluronic F127 (F127) was complexed with HD to form a micelle layer. Dopamine can assist coating deposition on the tube under weak alkaline conditions, while improving the coating stability. The micelle layer formed by F127 and HD provides excellent water retention and lubrication performance. The friction coefficient of the HD-F127 coating was 56% lower than that of the control, as determined by a friction performance test.

Surface-enhanced Raman spectroscopy (SERS) is a powerful molecular spectroscopy technique that combines Raman spectroscopy with nanostructured metallic surfaces to amplify the Raman signals of target molecules by more than 10³. The high sensitivity of SERS poses a significant opportunity for pesticide detection in complex matrices at ultralow concentrations. In this study, we improved the SERS sensitivity for imidacloprid (IMD) by employing silver nanostars (AgNs) coated with gold nanostars (AuNs) as the SERS-active substrate. The SERS response towards IMD detection increased based on the combination of AuNs and AgNs on the substrate surface. The intensity of the SERS signal of IMD using the AuNs/AgNs substrate increased compared to using individual metal nanoparticle substrates. The excellent reproducibility of SERS intensity using the AuNs/AgNs substrate was achieved with a low relative standard derivative (RSD) of 4.87% for 20 different spots on the same sample and 5.19% for 20 different samples. This detection system can be used for multiple tests, which is crucial for the advancement of handheld sensors designed for field use, where minimal or no high-level technical support is accessible.

Antibiotic concentrations in wastewater generated by industries such as sewage treatment plants, medical pharmaceuticals and aquaculture has exceeded acceptable levels. It is particularly urgent to seek a method that can efficiently remove antibiotics. The removal potential of three quinolone antibiotics, pefloxacin (PF), levofloxacin (LF) and norfloxacin (NF), in simulated contaminated water was studied using a biochar-based nanomaterial prepared by a hydrothermal method. The data were fitted with adsorption kinetics, isotherms and thermodynamics. The results showed that ZnS–MoS₂ activated biochar (ZMMBC) acheived maximum adsorption amounts of 199.42, 125.00 and 142.58 mg g^–1 for PF, LF and NF, suggesting that ZMMBC has excellent adsorption performance. The adsorption mechanisms of PF, LF and NF molecules on ZMMBC include complexation, pore filling, π–π interactions, electrostatic interactions and hydrogen bond interactions.

The reactions of pyrethrin I, cinerin I and jasmolin I with sodium hydroxide in ethanol afforded an approximately 1:1 ratio of two respective cyclopentadienone dimers, isolated in good yield. A combination of one-dimensional and two-dimensional NMR spectroscopic studies allowed determination of the structure and stereochemistry of the dimers. The dimers are formed by cycloaddition reactions of the less substituted alkene of the cyclopentadienone, and by regioisomeric endo transition states. Density functional theory calculations were in accord with the experimental findings showing the products formed by ambimodal transition states. One such transition state led to two initial products with the less stable product undergoing facile conversion to the other more stable, experimentally observed product. These studies clarify the structures of the altered pyrethrolone reported by Staudinger and Ruzicka in 1924.

Diglycolamide (DGA) extractant is a kind of rare-earth extractant with promising applications that has the advantages of high extraction capacity, ease of synthesis, good thermal stability and good radiation stability. It is a green extractant that contains only four elements, C, H, O and N, and produces no residue after incineration. The properties of DGAs containing branched N,N′-alkyl substituents have been much studied in recent years, and it has been shown that branched side chains lead to better separation. The introduction of structurally rigid elements in DGA provides new possibilities for separation of rare earth elements (REEs). Owing to the tiny differences in the chemical properties of adjacent REES, the simple use of DGA extractant cannot meet all separation requirements, and a masking agent is added to the aqueous phase to improve the separation by coextraction to meet the requirements of different processes. This review presents the structural analysis of the complexes and crystals of diglycolamide extractants with rare-earth ions through different characterization means, and the effects of different structural extractants, solvents, nitric acid and phase modifiers on extraction behavior are reviewed. This review pays special attention to the effect of the side chain structure of diglycolamide on extraction behavior, which provides a theoretical basis and guiding direction for the field of separation of the REEs by diglycolamide extractants.

Rare-earth perovskite oxides have become a research hotspot in the fields of environment and energy owing to their structural tunability, excellent redox properties, high stability and high catalytic activity. Researchers have designed and developed different rare-earth perovskite catalysts for tackling environmental pollutants in recent years. This review summarizes recent research progress on rare-earth perovskite catalysts in the catalytic oxidation and photocatalytic degradation of pollutants, gas sensing of volatile organic compounds and photocatalytic water splitting for hydrogen production and carbon dioxide reduction and conversion, and summarizes the mechanism of these reactions. It also discusses in detail the relationship between structural modification, synthesis process and the physical–chemical properties of the catalysts. Finally, the challenges with rare-earth chalcocite catalysts in the field of environment and energy are discussed.

A facile oxidative cyclization of β-ketothioamides for the simultaneous formation of a compound library similar to natural product benzothiazole derivatives has been developed. The oxidative cyclization of β-ketothioamides resulted in the simultaneous formation of four classes of previously unknown benzothiazole derivatives. This chemistry’s versatility adds a valuable component to the methodology for obtaining benzothiazole derivatives.

In this study, the corrosion inhibition behavior of N,N′-(1,4-phenylene)bis(1,1-di(pyridin-2-yl)methanimine) (PBDPM) on mild steel in 1 M HCl at 30°C was evaluated under steady conditions. The corrosion inhibitor was synthesized by a one-step method. Electrochemical, energy dispersion spectrum (EDS) and water contact angle results revealed the adsorption behavior of the inhibitor at the metal–solution interface. The adsorption of PBDPM obeys the Langmuir adsorption isotherm. It is obvious that PBDPM exhibits good inhibition performance presumably due to its high surface coverage, as it forms a dense protective film on the surface of mild steel. The adsorption configuration and structure–activity relationships of the inhibitor were also explored theoretically by density functional theory (DFT) and molecular dynamics (MD), and the thermodynamic parameters and molecular active sites (the values of electrophilic attack and nucleophilic attack) were calculated.

This Highlight article considers key contributions made by Professor Brian Yates to the Australian chemistry academic community in recognition of his seminal leadership that led to the establishment of the Chemistry Threshold Learning Outcomes (CTLOs) as national assessment standards. These CTLOs currently underpin the Royal Australian Chemical Institute (RACI) process of the professional accreditation of chemistry majors in Australian tertiary institutions and, hence, provide benchmarks of learning in our discipline. Examples of contemporary assessment approaches in chemistry are presented to inform academics who are seeking to assess learning outcomes beyond threshold standards and to inspire future innovative assessment approaches.

A novel Co(OAc)₂/N-hydroxyphthalimide (NHPI)-catalyzed oxidation of 3-arylmethyl sulfonyl imines to prepare 3-arylcarbonyl analogues has been realized. 3-Arylcarbonyl sulfonyl imines were comprehensively synthesized from benzyl substrates for the first time. The reactions proceeded in moderate to excellent yields. Mechanistic investigation suggests that 3-(hydroperoxy(phenyl)methyl)benzo[d]isothiazole 1,1-dioxide A is the key intermediate for the formation of products 2.