Australian Journal of Chemistry
Volume 65 Number 9 2012
RESEARCH FRONTS: 1. Second Molecular Materials Meeting (M3) @ Singapore; 2. Second International Collaborative and Cooperative Chemistry Symposium
This foreword introduces some selected papers presented at the 2nd Molecular Materials Meeting in Singapore (M3@Singapore) from 9 to 11 January 2012 that was organized by the Institute of Materials Research and Engineering (IMRE) of A*STAR, Singapore. The conference brought together leading researchers in the disciplines of chemistry, materials science, physics, biology, medicine and engineering to discuss the advances in molecular materials and cultivate cross-disciplinary research.
Conducting material-incorporated core-shell particles were synthesized and adopted for electrorheological materials when dispersed in medium oils. Under an applied electric field, they exhibited a fluid-like to a solid-like phase transition, which correlated with the coated material, thickness and dielectric properties of the particles.
CH12126Heterocyclic-Functionalized Organic Dyes for Dye-Sensitized Solar Cells: Tuning Solar Cell Performance by Structural Modification
Dye-sensitized solar cells (DSSCs) have been investigated extensively as promising candidates for renewable-energy systems. With various heterocycles incorporated into the dye sensitizers, different solar-cell performances are obtained. This review focuses on recent progress in the molecular design of heterocyclic-functionalized organic dyes for efficient DSSCs, and special attention has been paid to the relationship between the properties and the structures of the heterocyclic-functionalized organic dyes.
Carbon nanotubes (CNTs) have attracted enormous attention for the fuel cell research because of their unique structure and extraordinary mechanical, electrical, and thermal properties. In this review, we summarize and compare the recent research and development on CNT-based fuel cells, particularly focussing on CNTs as a catalytic support for enhanced electro-catalytic activity, metal free electro-catalysts for the oxygen reduction reaction and fillers in the polymer electrolyte membrane in fuel cells.
A poly(acrylic acid) thin film with embedded Ag nanoparticles demonstrates pH-induced variation of plasmonic properties due to the change of distance between Ag nanoparticles during swelling and shrinking of the polymer matrix. Dynamic plasmonic properties should be applicable for optoelectronic devices and sensors.
CH12116Carbazole-Functionalised Poly(1-phenyl-1-alkyne)s: Synthesis, Light Emission, and Fluorescent Photopatterning
Carbazole-functionalized poly(1-phenyl-1-alkyne)s were synthesised in high yields with high molecular weights by transition metal-catalysed acetylene polymerisation. All the polymers possessed high thermal stability and emitted strong photo-and electroluminescence. They were photosensitive and could be readily photo-oxidized to generate fluorescent patterns.
CH12175Gold/Palladium Bimetallic Alloy Nanoclusters Stabilized by Chitosan as Highly Efficient and Selective Catalysts for Homocoupling of Arylboronic Acid
A bimetallic Au/Pd-alloyed catalyst exhibited superior catalytic activity and selectivity towards homocoupling of arylboronic acids under aerobic conditions. It was found that there was an optimum alloy ratio for the best bimetallic catalyst, i.e. the rate of conversion of phenylboronic acid increased with the Pd content when it was increased from 5 to 19 % but decreased with a Pd content higher than 19 %.
CH12171Pyridine-Incorporated Dihexylquaterthiophene: A Novel Blue Emitter for Organic Light Emitting Diodes (OLEDs)
The synthesis, characterisation, and blue organic light emitting diodes (OLEDs) device characteristics using 2,5-bis(5′-hexyl-[2,2′-bithiophen]-5-yl)pyridine (Th4PY) as a blue emitter are reported. The OLED using 4′,4′′-tris(N-carbazolyl)triphenylamine (TCTA) matrix with Th4PY emitter exhibited highly efficient sky-blue emission with a low turn-on voltage of 3 V and a maximum brightness close to 15000 cd m–2 at 8 V, and a maximum luminous efficiency of 7.4 cd A–1 (6.3 lm W–1) with CIE coordinates of x = 0.21, y = 0.32.
CH12112Structure–Property Relationships Based on Phenyl-1H-Pyrrole End-Capped Thiophene Semiconductors
A new series of phenyl-1H-pyrrole end-capped thiophene oligomers has been synthesized, and the relationships between the molecular structures and electronic properties were investigated. As the semiconductors are in organic thin-film transistors, they all show good p-type organic thin-film transistor properties.
Electroluminescence (EL) from glass fibres with CdTe quantum dots (QDs) is reported. EL appeared at relatively low direct current electric field. This suggests potential applicability of the QD-incorporated fibres in low voltage driven EL devices.
This research front contains contributions in the areas of synthetic organic methodology, green chemistry, medicinal and biological chemistry, polymer and materials chemistry, and in-depth spectroscopy using magnetic circular dichroism, which were presented at the 2nd International Collaborative and Cooperative Chemistry Symposium (2nd ICCCS) from 30 October to 2 November 2011 at the University of Queensland.
CH12062Regioselective Addition of 1,3-Dicarbonyl Dianions to Carbonyl Compounds: One Pot Lactonization and Ketalization of δ-Hydroxy-β-keto Esters to Protected Pyrone Derivatives
A simple and efficient strategy for the synthesis of 6-substituted-2-pyrone derivatives in good yield by BF3·OEt2 mediated one pot cyclization and keto-protection of δ-hydroxy-β-keto esters obtained via regioselective addition of 1, 3-dicarbonyl dianion of ethyl acetoacetate to aldehydes and ketones is described.
CH12059Transcription Inhibition by Organometallic Ruthenium–Arene Anticancer Complexes in Live Mammalian Cells
Transcription experiments carried out in live mammalian cells using plasmid probes damaged by RAPTA complexes revealed that increasing steric bulk of arene ligand does not improve their ability to arrest transcription.
Palladium-catalyzed [4 + 1] type annulations leading to dibenzofulvenes are reported, which involve double cross-coupling reactions of 1,1-diborylalk-1-enes with 2,2′-dibromobiaryls and of 9-stannafluorenes with 1,1,-dibromoalk-1-enes.
CH12073Unprecedented Mn(II)–Phosphate 3D Coordination Polymer with Novel pkb1 Topological Network Showing Spin-Canted Antiferromagnetism
A novel Mn(II)–phosphate coordination polymer has been synthesized under hydrothermal conditions. The complex has a novel 3D non-interpenetrated novel pkb1 network that exhibits spin-canted antiferromagnetism at low temperature.
CH12066Fluorescence, Phosphorescence, and Delayed Fluorescence of Benzil in Imidazolium Ionic Liquids
Even a non-degassed solution of benzil exhibits phosphorescence at room temperature in ionic liquids due to low solubility of oxygen in these media compared with the conventional molecular solvents. The existence of multiple conformers in frozen conditions has been established by the excitation wavelength dependence of the phosphorescence spectra at liquid nitrogen temperature.
The sharp zero-phonon electronic origins of the 3A2g → 3T2g transition in Ni(ii)/MgO, allows the Zeeman split levels to be observed. The reason why only some of the spin-orbit components are observed is explained in terms of the sensitivity of the levels to an excited state Jahn–Teller distortion.
CH12034Static and Dynamic Aspects of Supramolecular Interactions of Coumarin 153 and Fluorescein with Bovine Serum Albumin
The static and dynamic aspects of supramolecular interactions between coumarin 153 (C153) and fluorescein (FL) with bovine serum albumin (BSA) has been determined by steady-state absorption, fluorescence, fluorescence resonance energy transfer, site marker competitive experiments, and a molecular docking study. It has been revealed that C153 binds to domain IIIA of BSA whereas FL binds non-specifically. Kinetics of binding has also been studied by stopped-flow method.
CH12051Structural Insights into the Active Site of Human Sodium Dependent Glucose Co-Transporter 2: Homology Modelling, Molecular Docking, and 3D–QSAR Studies
The human sodium dependent glucose co-transporter 2 is an important diabetes target and we have modelled the 3D structure of this protein using homology modelling methods. The receptor based molecular docking of C-aryl glucoside analogue inhibitors into the enzyme active site and the ligand based 3D-QSAR (quantitative structure activity relationship) analysis of inhibitors were carried out. The two methods provided complementary results and showed that the presence of electronegative substituents on meta and ortho positions of the terminal phenyl ring is required to improve inhibitory activity. An electronegative substitution of moderate steric bulk at the para position is required for greater activity of the inhibitors.
CH12275Sixty Years Young: The Diverse Biological Activities of Metal Polypyridyl Complexes Pioneered by Francis P. Dwyer
Sixty years ago, the Australian chemist Francis P. Dwyer pioneered the use of ruthenium polypyridyl complexes as biologically active molecules against an astonishing range of biological targets. This perspective commemorates the anniversary of Dwyer’s landmark publication, summarises his wider achievements in biological inorganic chemistry, and discusses the contribution of this work to the development of modern biological and medicinal inorganic chemistry.
Ruthenium compounds of the type trans-[Ru(NO)(NH3)4(L)]X3 were tested for antitumour activity in vitro against murine melanoma and human tumour cells. The ruthenium complexes induced DNA fragmentation and morphological alterations suggestive of a necrotic tumour cell death. Complexes for which L = isn and imN were effective in vivo in a syngeneic model of murine melanoma B16F10, reducing subcutaneous tumour development rate and increasing animal survival.
We synthesised uniform chrysanthemum-like Bi2S3 microspheres, assembled by nanowires via a one-step facile hydrothermal route. The formation mechanism of chrysanthemum-like Bi2S3 microspheres was also proposed. The photovoltaic performance of Bi2S3 chrysanthemum-like microspheres was investigated to show their potential application in dye-sensitised solar cells.
CH12227Synthesis and SAR of a Library of Cell-Permeable Biotin-R8ERY* Peptidomimetics Inhibiting α4β7 Integrin Mediated Adhesion of TK-1 Cells to MAdCAM-1-Fc
The synthesis of a library of α4β7 integrin inhibitors based on the biotin-R8ERY (R8 = (l-arginine)8) motif is reported, wherein the tyrosine residue has been modified. The peptidomimetics were evaluated for their ability to inhibit adhesion of mouse TK-1 T-cells to the α4β7 ligand MAdCAM-1.