Australian Journal of Chemistry

The foreword to this research front dedicated to Professor Alan Bond provides an account of his distinguished career in inorganic and electroanalytical chemistry in Australia and overseas, and also describes his many awards and achievements.

Grafting from aryldiazonium salts is a popular method for preparing strongly adherent organic coatings on many surfaces. Usually, the coatings are loosely packed disordered multilayers; however, over the past decade, strategies have emerged for generating monolayers. This review describes these approaches, illustrates some of their applications, and highlights the advantages and disadvantages of each.

Aerial oxidation of Cd(TCNQ)₂ during slow recrystallization in tetrahydrofuran produced a dicarboxylate ligand–Cd complex, with the N 1s XPS spectrum showing that this chemical transformation is complete.

An integrated device is developed that incorporates a sensor, readout system, and battery on paper. The electrochromic readout system allows the pH range of a sample solution to be determined visually rather than using an LCD display or voltmeter. The integrated potentiometric sensor and readout system provides a cost-effective and lightweight solution for pH monitoring.

The electropolymerisation of N-ethylanilinium trifluoroacetate, a protic ionic liquid (PIL), was carried out, where the PIL served as the monomer precursor, solvent, and supporting electrolyte for the polymerisation process resulting in different morphologies, a greener approach to production, and a highly processable polymer.

Electrochemical determination of mass-transport parameters is often subject to small errors, which influence the outcomes of voltammetric experiment–theory comparisons. In particular, a perilous situation emerges when a quasi-reversible model with slightly overestimated mass-transport parameters is used to quantify the electrode kinetics for a system that approaches a reversible limit.

Two related [Pt(NH₃)₄]²⁺ complexes, [Pt(NH₃)₄](TCNQ)₂·(DMF)₂ (1) and [Pt(NH₃)₄](TCNQ)₂ (2) are characterized using X-ray, electrochemistry, vibrational, and electronic spectroscopy. Unexpectedly, 2 is not a catalyst for the redox reaction of ferricyanide and thiosulfate, and the rationale for this is presented.

Oxidations of W(CO)₄(LL) compounds were investigated electrochemically. The electrogenerated radical cations are unstable toward disproportionation, carbon monoxide substitution, and nucleophilic attack. The kinetics of these reactions were examined using a number of techniques including a.c. voltammetry and chronocoulometry. Infrared spectroelectrochemistry was used to characterize two [W(CO)₄(LL)]⁺ species.

The electrical impedance of anodically formed iridium oxide is assessed and correlated with the effective electrode area and charge density for bionics applications.

The generation of a radical species from the reduction of 1-ethylpyridiniuim bromide has been shown to passivate Zn/Zn^II redox after one cycle. Both deposition morphology and nucleation process are also altered in the presence of the radical species.

Crystalline neutral red accelerates microbial methane generation from coal. Industrial scale-up requires knowledge of crystalline polymorphs that may behave differently with methanogens. Temperatures in the dark, subterranean environments where methanogenesis occurs range from 50–70°C, conditions where neutral red crystallises or transforms to a new polymorph.

A novel MoO₂ composite supported on mesoporous graphene oxide (m-MoO₂/GO) is successfully synthesised. The introduction of a mesoporous structure into GO sheets not only promotes the catalytic activity, but also makes m-MoO₂/GO more effective in catalysing olefins with a long carbon chain and large ring size.

A series of all-trans acceptor–π-donor (acceptor) compounds were conveniently synthesised via the three-step synthetic method Arbuzov reaction, solvent-free Horner–Wadsworth–Emmons reaction, and Mizoroki–Heck reaction. They all exhibit obvious solvatochromic effects, strong two-photon excited fluorescence, and large two-photon absorption cross-sections.

The ability of gold anti-arthritic agents and gold nanoparticles to alter production in RAW264.7 macrophages of a number of cellular mediators of inflammation, including reactive oxygen and nitrogen species, interleukin-10 and tumour necrosis factor, have been compared.

We report on the 1,3-dipolar cycloaddition of the triple bond in an ethynyl-substituted nitronyl nitroxide to heteroaromatic N-imines. The reaction opens a new pathway to polyfunctional nitronyl nitroxides with pyrazolo[1,5-a]pyridine or related substituents that are in demand in coordination chemistry and molecular magnetism fields.

Polyurethanes (PUs) were synthesised using methylene diphenyl diisocyanate (MDI), polytetrahydrofuran ether diol (PTMG), and chain extenders containing different amounts of aliphatic side chains. Hybrid materials were then prepared by reacting the PUs with nano-TiO₂. The effects of different molecular structures of the chain extenders on the surface properties of PU coatings and the hybrid materials were investigated.

A simple, multigram-scale preparation of 1,4-bis(trimethylsilyl)buta-1,3-diyne that minimises risks associated with the preparation of this useful compound is reported.

The catalytic activity of nanofibre sepiolite as a green and non-toxic catalyst was investigated in the synthesis of chromene derivatives.

The formation of copper nanoparticles (CuNPs) in the presence of N-donor ligands results in changes in the nanoparticle optical properties and particle size distributions, depending on the nature of the donor ligands. CuNP formation kinetics are independent of the nature of the donor ligand.

Synthesis of star polymers using reversible addition–fragmentation chain transfer (RAFT) polymerization through core-first and arm-first preparation are outlined. Biomedical applications of the resulting star polymers in controlled delivery of chemotherapeutic agents, protein inhibitors, signalling molecules, siRNA, and in constructing macromolecular magnetic resonance imaging (MRI) contrast agents and fluorescent imaging agents, and theranostic vectors are discussed.

Portable dielectric barrier discharge ionization is a plasma-based ion source for mass spectrometry that is significantly ‘softer’ than the two most widely used plasma-based ionization sources. This is important for the detection of intact molecules with thermolabile bonds, such as many explosives, and some chemical weapons and organic pollutants.

A series of carbon-based solid acid catalysts derived from biomass was prepared and used for the conversion of fructose to 5-HMF, which is a very important platform chemical due to its unique chemical structure. The results suggest that sulfonated carbon materials exhibit remarkable catalytic capability for fructose dehydration to 5-HMF.

The synthesis of 21-membered imine- and amine-linked tris-indole macrocycles starting from 7-nitroethylindoles is described.

New hole-transport materials have been applied in silicon–carbon nanotube solar cells to yield better performance.

A range of 3-hydroxymethylindoles undergo acid-catalysed reactions involving ipso-electrophilic substitution with the extrusion of methanal and the formation of diindolylmethane moieties. Both inter- and intramolecular processes lead to macrocyclic compounds.

Peptide toxins from sea anemones may provide valuable drug leads. However, little is known about peptide toxin distribution in discrete morphological regions in sea anemones, which perform distinct biological functions. We utilise imaging mass spectrometry to examine peptide distribution in the Australian sea anemone, Oulactis muscosa, and infer biological function.

Catalyst supports play a vital role in the formation of active cobalt sites for the N₂O decomposition reaction. Co²⁺ and Co³⁺ are the highly active cobalt species. The acidic properties of the ZSM-5 support changes with the cobalt loading.

A prodrug mPEG-b-PCL-(g-PTX)-b-PLA-(g-LA) has been synthesized, which may exchange ligands with QDs to form a nanotheranostic system (prodrug-co-QDs). This novel system exhibited good controlled drug release behaviour due to the ester linkage between the drug and polymer. By using typical cancer cell lines, we showed that this nanotheranostic system is promising in cancer diagnosis and treatment in vitro.

The co-operative stabilizations associated with the bending of the σ_C–C toward C–F bonds and total hyperconjugative generalized anomeric effect in the cis-configuration of 1,2-difluoroethene overcome the destabilizations associated with the exchange component and dipole–dipole interactions, leading to the preference of the cis-configuration in the compound.

The present paper reports a new hybrid cyclohexaphosphate which was characterized by different techniques (NMR, IR, UV-vis) and evaluated (electrical and biological). This reported compound exhibits an acidic character which is rarely observed with this type of condensed phosphate. In addition, this material is distinguished from others by its higher thermal stability and more pronounced antioxidant activity.

New azomethine receptors were designed and synthesised for rapid and naked eye detection of inorganic fluoride anions in semi-aqueous media. The sensing ability of the receptors towards F⁻ has been investigated spectroscopically. By using F⁻ and H⁺ as chemical inputs and the absorbance as output, an INHIBIT logic gate was constructed, which exhibits ‘Write–Read–Erase–Read’ ability without obvious degradation in its optical output.

The reactions of classic iridium and rhodium complexes with iodine(iii) oxidants are described. All reactions resulted in two-electron oxidation. Ligand exchange and anion scrambling were observed in monodentate ligand-containing complexes. In the case of reacting Iⁱⁱⁱ reagents with chelating ligand-containing complexes, no scrambling was observed, leading to the isolation of well-defined complexes.

A new porous 3-dimensional coordination framework containing the novel photoactive ligand 5-((4-tert-butyl)phenylazo)isophthalic acid displays light-dependent spectroscopic properties.

Star-shaped block copolymers based on poly(N-vinylcaprolactam) and functionalized with polyethylene glycol have been synthesized. The star-shaped block copolymers self-assemble spontaneously into aggregates in water and were used to encapsulate methotrexate.

A novel, simple and straightforward combinatorial method for the synthesis of new substituted 3-(arylamino)-6,7-dihydro-1H-indazol-4(5H)-one derivatives has been developed. The synthesis was achieved via a one-pot three-component reaction of aromatic isothiocyanates, substituted 1,3-cyclohexanediones, and hydrazine hydrate in dimethyl sulfoxide.

Novel 1,3-oxazine hybrids of sesamol and quinoline have been synthesized via one-pot reaction of sesamol/6-hydroxyquinoline, aromatic amines, and formaldehyde. The structures of all the novel compounds were confirmed by spectral data. The structure of the synthesized hybrids was also confirmed by X-ray crystallographic studies.

Synthesis and binding behaviour of bile acid-based flavin receptors containing 2,6-diaminopyridine and aromatic moieties are reported. These receptors display significant influence of steric and aromatic π-stacking interactions, along with hydrogen bonding, on their binding with N-(10)-hexylflavin derivative.

Zeolite X base catalysts containing alkali metal ions are prepared from amorphous bamboo leaf ash. The catalysts are found to be highly active in cyanoethylation of methanol under an instant heating environment that mimics microwave fast heating.

An effective, high-yielding strategy for O-glycosylation is studied and applied in solid-phase synthesis.

Secondary amines react with maleic anhydride under kinetic control across the C=O functionality exclusively. The product changes into N-substituted maleimic acid under thermodynamic control. The Fukui functions determined at the B3LYP/6-31G* level reveal that the carbon atom of the carbonyl group is the hardest site, thus making it the preferred site for the nucleophilic attack.

A novel alkaloid-like compound containing the azabicyclo[3.3.1]nonane core is reported to be the first instance of using the bridged Ritter reaction with hydrogen cyanide. The structure of this unique and unexpected compound was determined with the aid of X-ray crystallography.

Peptide nanofibres with arginine as a building block have been prepared via a self-assembly method and decorated with Cu and Ni nanoparticles. These prepared nanostructural compounds present a unique catalytic activity for the synthesis of 5-substituted 1H-tetrazoles and the N-arylation of amines.

The hydrogenated derivative of levoglucosenone was functionalised at the α-position with aldol chemistry using a series of aromatic aldehydes. The benzylidene derivative was then hydrogenated stereospecifically and the product transformed using a Baeyer–Villiger reaction into (3R,5S)-3-benzyl-5-(hydroxymethyl)-4,5-dihydrofuran-2(3H)-one, a chiral building block that can be used for the synthesis of the protease inhibitor indinavir.

A simple and highly sensitive method for the detection of hydrogen peroxide in food samples was developed by electrodepositing Cu and MnO₂ onto a g-C₃N₄ coated glassy carbon electrode. The sensor exhibits high selectivity, good stability, and reproducibility.

Different aminoalcohol ligands (TEA, DEA, and MEA) were found to affect the size and optical properties (band gap and emission peak) of ligand-stabilized ZnO quantum dots. Ligands of higher polarity and larger molar volume produce smaller, more monodisperse ZnO quantum dots. As the size of ZnO quantum dots decrease, the optical properties are blue-shifted.

SnFe₂O₄ has been widely used as a magnetic material or catalyst for the oxidative removal of organic pollutants, but never used as an electrode material in lithium ion batteries. In this study, binder-free SnFe₂O₄-rGO hybrid films with both horizontal and vertical channels were fabricated through electrophoretic deposition to present excellent electrochemical performance of lithium ion batteries.

Heterocycles fused to quinoline frameworks widely occur in many biologically active natural products and in medicinally important drugs. Our strategy represents the first collective synthetic concise and efficient entry to nine novel condensed tetracyclic quinolinones by Friedel–Crafts cycliacylations. The simplicity and wide variability of the procedures highlights the efficiency of the methodology for constructing complex fused-ring systems.

The attempted synthesis of a β-keto imidazolidinone nitroxide by oxidation of the β-hydroxy imidazolidinone precursor led to an unexpected ring-opening reaction. A β-fragmentation mechanism is suggested, rather than a Baeyer–Villiger rearrangement.

A simple procedure for the condensation of the bio-derived furfurals, 5-(methyl)furfural (MF) and 5-(chloromethyl)furfural (CMF), with primary amines is described. The experiments were conducted in both batch and flow conditions, with reaction times as short as 60 s. Mild reaction conditions were necessary for CMF in order to selectively react on the aldehyde and not the methyl-chlorine group.

Orpiment (As₂S₃) quantum dots (QDs) were first synthesised through top-down and bottom-up routes, and exhibit strong blue photoluminescence emission. They were effective against murine melanoma B16 cells through induction of apoptosis. Moreover, self-assemblies of orpiment QDs were fabricated by destroying the protective surface ligand layer surrounding the inner orpiment cores by addition of an acid.

In this research, relatively high surface area mesoporous ZnS nanoparticles have been synthesised using two different media. The mechanism of the by-product assisted synthesis of the prepared mesoporous ZnS nanoparticles in EtOH has been investigated using field emission scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, diffuse reflectance spectroscopy, N₂ adsorption–desorption, and FT-IR spectroscopy analyses.