1,002 results match your criteria: "School of Chemical and Physical Sciences[Affiliation]"

Phytophthora diseases cause devastation to crops and native ecosystems worldwide. In New Zealand, Phytophthora agathidicida is threatening the survival of kauri, an endemic, culturally and ecologically important tree species. The current method for detecting P.

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Dihydrogen Activation by Lithium- and Sodium-Aluminyls.

Angew Chem Int Ed Engl

October 2021

School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6012, New Zealand.

To date, aluminyl anions have been exclusively isolated as their potassium salts. We report herein the synthesis of the lithium and sodium aluminyls, M [Al(NON )] (M=Li, Na. NON =[O(SiMe NDipp) ] ; Dipp=2,6-iPr C H ).

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Article Synopsis
  • - The goal of biocatalysis is to replicate the way eukaryotic cells perform complex chemical reactions in a controlled manner, but increasing complexity often makes traditional batch processes ineffective.
  • - To address this, continuous flow systems were utilized to enable successful multistep biocatalytic reactions by transporting reactive intermediates directly through various biocatalyst modules.
  • - This method demonstrated the capability to synthesize diverse amines and successfully produced the natural product 4O-methylnorbelladine using a specific series of biocatalytic reactions without unwanted cross-reactivity.
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Natural Products from Tongan Marine Organisms.

Molecules

July 2021

School of Chemical and Physical Sciences, Centre of Biodiscovery, Victoria University of Wellington, Wellington 6140, New Zealand.

The islands of the South Pacific Ocean have been in the limelight for natural product biodiscovery, due to their unique and pristine tropical waters and environment. The Kingdom of Tonga is an archipelago in the central Indo-Pacific Ocean, consisting of 176 islands, 36 of which are inhabited, flourishing with a rich diversity of flora and fauna. Many unique natural products with interesting bioactivities have been reported from Indo-Pacific marine sponges and other invertebrate phyla; however, there have not been any reviews published to date specifically regarding natural products from Tongan marine organisms.

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Article Synopsis
  • The study introduces two new self-assembled amphiphiles, SQS-1 and SQS-2, derived from the squaramide structure, showing full solubility in various solvents.
  • Their self-assembly leads to the creation of nanoscale crystalline domains and fibrillar films, confirmed by SEM analysis.
  • Both compounds exhibit anion recognition capabilities in DMSO, with SQS-1 showing a noticeable color change when exposed to HPO, indicating its potential for detecting specific anions over others.
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Efficient energy transport is desirable in organic semiconductor (OSC) devices. However, photogenerated excitons in OSC films mostly occupy highly localized states, limiting exciton diffusion coefficients to below ~10 cm/s and diffusion lengths below ~50 nm. We use ultrafast optical microscopy and nonadiabatic molecular dynamics simulations to study well-ordered poly(3-hexylthiophene) nanofiber films prepared using living crystallization-driven self-assembly, and reveal a highly efficient energy transport regime: transient exciton delocalization, where energy exchange with vibrational modes allows excitons to temporarily re-access spatially extended states under equilibrium conditions.

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Chemical synthesis of C6-tetrazole ᴅ-mannose building blocks and access to a bioisostere of mannuronic acid 1-phosphate.

Beilstein J Org Chem

July 2021

Lennard-Jones Laboratory, School of Chemical and Physical Sciences, Keele University, Keele, Staffordshire, ST5 5BG, U. K.

Article Synopsis
  • Alginate is a versatile polysaccharide known for its biocompatibility and useful properties stemming from charged carboxylate groups in its structure.
  • The research focuses on creating modified mannuronic acid building blocks, where the carboxylate is replaced with a bioisosteric tetrazole to explore new materials with different properties.
  • The synthesis involves converting a C6-nitrile to thioglycosides with protected tetrazole and developing C4-protected donors for assembling oligosaccharides with unique characteristics.
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Bandgap control in two-dimensional semiconductors via coherent doping of plasmonic hot electrons.

Nat Commun

July 2021

Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, Zhejiang, China.

Bandgap control is of central importance for semiconductor technologies. The traditional means of control is to dope the lattice chemically, electrically or optically with charge carriers. Here, we demonstrate a widely tunable bandgap (renormalisation up to 550 meV at room-temperature) in two-dimensional (2D) semiconductors by coherently doping the lattice with plasmonic hot electrons.

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A dimeric β-diketiminato ytterbium(II) hydride affects both the two-electron aromatization of 1,3,5,7-cyclooctatetraene (COT) and the more challenging two-electron reduction of polyaromatic hydrocarbons, including naphthalene (E =-2.60 V). Confirmed by Density Functional Theory calculations, these reactions proceed via consecutive polarized Yb-H/C=C insertion and deprotonation steps to provide the respective ytterbium (II) inverse sandwich complexes and hydrogen gas.

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Printed monolith adsorption as an alternative to expanded bed adsorption for purifying M13 bacteriophage.

J Chromatogr A

August 2021

School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand. Electronic address:

An ordered 3D printed chromatography stationary phase was used to purify M13 bacteriophage (M13) directly from crude cell culture. This new approach, which offers the same advantages as expanded bed adsorption (EBA) with regard to tolerating solids-laden feed streams but without the corresponding issues associated with fluidized bed stability that affect the latter, can be described as "printed monolith adsorption (PMA)". PMA columns (5, 10 and 15 cm length by 1 cm diameter) were made via a wax templating method from cross-linked cellulose hydrogel and functionalized with a quaternary amine ligand.

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Surface model of the human red blood cell simulating changes in membrane curvature under strain.

Sci Rep

July 2021

MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University Wellington, Wellington, New Zealand.

We present mathematical simulations of shapes of red blood cells (RBCs) and their cytoskeleton when they are subjected to linear strain. The cell surface is described by a previously reported quartic equation in three dimensional (3D) Cartesian space. Using recently available functions in Mathematica to triangularize the surfaces we computed four types of curvature of the membrane.

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A mechanistic understanding of surface Bi enrichment in dilute GaBi systems.

Phys Chem Chem Phys

July 2021

MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Physics, University of Auckland, Private Bag 92019, Auckland, New Zealand.

Experiment has shown that dilute GaBi systems produce a range of self-organised nanostructured patterns at the surface [Tang et al., Nat. Nanotechnol.

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The relationship between the structure and the properties of a drug or material is a key concept of chemistry. Knowledge of the three-dimensional structure is considered to be of such importance that almost every report of a new chemical compound is accompanied by an X-ray crystal structure - at least since the 1970s when diffraction equipment became widely available. Crystallographic software of that time was restricted to very limited computing power, and therefore drastic simplifications had to be made.

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Phospholipid fatty acid (PLFA) analysis as a tool to estimate absolute abundances from compositional 16S rRNA bacterial metabarcoding data.

J Microbiol Methods

September 2021

School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand; Centre for Biodiversity and Restoration Ecology, Victoria University of Wellington, Wellington 6012, New Zealand. Electronic address:

Microbial biodiversity monitoring through the analysis of DNA extracted from environmental samples is increasingly popular because it is perceived as being rapid, cost-effective, and flexible concerning the sample types studied. DNA can be extracted from diverse media before high-throughput sequencing of the prokaryotic 16S rRNA gene is used to characterize the taxonomic diversity and composition of the sample (known as metabarcoding). While sources of bias in metabarcoding methodologies are widely acknowledged, previous studies have focused mainly on the effects of these biases within a single substrate type, and relatively little is known of how these vary across substrates.

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Ultrafast transient absorption spectroscopy is a powerful tool to reveal excited state dynamics in various materials. Conventionally, probe pulses are generated via bulk supercontinuum generation or (noncollinear) optical parametric amplifiers whilst pump pulses are generated separately using (noncollinear) optical parametric amplifiers. These systems are limited by either their spectral density, stability, spectral range, and/or temporal compressibility.

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Recent studies with silver nanoparticles (AgNPs) and the history of silver metal as a broad-spectrum bactericidal and virucidal agent, places silver as one of the future biocidal candidates in the field of nanomedicine to eliminate bacteria and viruses, especially multidrug resistant ones. In this review, we have described the various morphologies of AgNPs and correlated the enhanced bactericidal activity with their prominent {111} facets. In addition to prioritizing the characterization we have also discussed the importance of quantifying AgNPs and silver ion content (Ag) and their different mechanisms at the chemical, biological, pharmacological, and toxicological levels.

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Although the nucleophilic alkylation of aromatics has recently been achieved with a variety of potent main group reagents, all of this reactivity is limited to a stoichiometric regime. We now report that the ytterbium(II) hydride, [BDIYbH] (BDI = CH[C(CH)NDipp], Dipp = 2,6-diisopropylphenyl), reacts with ethene and propene to provide the ytterbium(II) n-alkyls, [BDIYbR] (R = Et or Pr), both of which alkylate benzene at room temperature. Density functional theory (DFT) calculations indicate that this latter process operates through the nucleophilic (S2) displacement of hydride, while the resultant regeneration of [BDIYbH] facilitates further reaction with ethene or propene and enables the direct catalytic (anti-Markovnikov) hydroarylation of both alkenes with a benzene C-H bond.

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We report the synthesis of aromatic germanimines [(HMDS)Ge═NAr] (Ar = Ph, Mes, Dipp; Mes = 2,4,6-MeCH, Dipp = 2,6-PrCH) and an investigation into their associated reactivity. [(HMDS)Ge═NPh] decomposes above -30 °C, while [(HMDS)Ge═NDipp] engages in an intramolecular reaction at 60 °C. [(HMDS)Ge═NMes] was shown to rearrange via a 1,3-silyl migration to give [(HMDS){(SiMe)(Mes)N}Ge(NSiMe)] in a 1:7 equilibrium mixture at room temperature.

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The attractive optical properties of metallic nanoparticles include the optically interesting but surprisingly not well understood dichroic effect, defined in this research as when particle colloids display different colours in transmitted and reflected light. Here we use a systematic experimental approach supplemented by theoretical Mie theory analysis to study the origin of this effect. The CloudSpec spectrophotometer has been utilised to produce quantitative scattering and absorption spectra for monodisperse spherical gold nanoparticles, allowing precise links to be made between the optical spectra and the colours observed.

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Coordination sphere hydrogen bonding as a structural element in metal-organic Frameworks.

Dalton Trans

May 2021

School of Chemical and Physical Sciences, Keele University, Keele ST5 5BG, UK.

In the design of new metal-organic frameworks, the constant challenges of framework stability and structural predictability continue to influence ligand choice in favour of well-studied dicarboxylates and similar ligands. However, a small subset of known MOF ligands contains suitable functionality for coordination sphere hydrogen bonding which can provide new opportunities in ligand design. Such interactions may serve to support and rigidity the coordination geometry of mononuclear coordination spheres, as well as providing extra thermodynamic and kinetic stabilisation to meet the challenge of hydrolytic stability in these materials.

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Development of Continuous Flow Systems to Access Secondary Amines Through Previously Incompatible Biocatalytic Cascades*.

Angew Chem Int Ed Engl

August 2021

Manchester Institute of Biotechnology (MIB) &, School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.

Article Synopsis
  • The main goal of biocatalysis is to imitate how eukaryotic cells perform complex multi-step reactions in a controlled way.* -
  • Traditional batch conditions struggled with complex biocatalytic cascades, prompting the use of continuous flow systems to make these reactions successful.* -
  • By generating reactive carbonyl intermediates and using a series of biocatalysts, the study successfully synthesized 4O-methylnorbelladine through a newly designed reaction sequence.*
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We propose a carbon-nanotube-based neural sensor designed to exploit the electrical sensitivity of an inhomogeneous fractal network of conducting channels. This network forms the active layer of a multi-electrode field effect transistor that in future applications will be gated by the electrical potential associated with neuronal signals. Using a combination of simulated and fabricated networks, we show that thin films of randomly-arranged carbon nanotubes (CNTs) self-assemble into a network featuring statistical fractal characteristics.

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Trehalose diamide glycolipids augment antigen-specific antibody responses in a Mincle-dependent manner.

Bioorg Chem

May 2021

School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand; Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, New Zealand. Electronic address:

Many studies have investigated how trehalose glycolipid structures can be modified to improve their Macrophage inducible C-type lectin (Mincle)-mediated adjuvanticity. However, in all instances, the ester-linkage of α,ά-trehalose to the lipid of choice remained. We investigated how changing this ester-linkage to an amide influences Mincle signalling and agonist activity and demonstrated that Mincle tolerates this functional group change.

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Diarylethene-Powered Light-Induced Folding of Supramolecular Polymers.

J Am Chem Soc

April 2021

Institute for Global Prominent Research (IGPR), Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.

Helical folding of randomly coiled linear polymers is an essential organization process not only for biological polypeptides but also for synthetic functional polymers. Realization of this dynamic process in supramolecular polymers (SPs) is, however, a formidable challenge because of their inherent lability of main chains upon changing an external environment that can drive the folding process (e.g.

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Oxidative Addition of Hydridic, Protic, and Nonpolar E-H Bonds (E = Si, P, N, or O) to an Aluminyl Anion.

Inorg Chem

April 2021

School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Kelburn, Wellington 6012, New Zealand.

The aluminyl anion K[Al(NON)] {NON = [O(SiMeNDipp)]; Dipp = 2,6-PrCH} engages in oxidative additions with the E-H (E = Si, P, N, or O) bonds of phenylsilane (PhSiH), mesityl phosphane (MesPH; Mes = 2,4,6-MeCH), 2,6-di--propylaniline (DippNH), and 2,6-di--butyl-4-methylphenol (ArOH). The resulting (hydrido)aluminate salts are formed regardless of the E-H bond polarity. All of the products were characterized by nuclear magnetic resonance and infrared spectroscopic techniques and single-crystal X-ray diffraction.

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