Publications by authors named "Gemma Turner"

Porphyrin-based porous materials are of growing interest as heterogeneous catalysts especially for reactions that are of importance to sustainability. Here we demonstrate that porous molecular crystals can be prepared by the simple co-crystallisation of tetraphenylporphyrin (TPP) with octa(2',6'-di-iso-propylphenoxy)phthalocyanine or some of its metal complexes [(dipPhO)PcM; M=H, Al-OH, Ti=O, Mn-Cl, Fe-Cl, Co, Ni, Cu, Zn, Ga-Cl, Ag, In-Cl or Au-Cl]. This process is facilitated by the efficient formation of the supramolecular heterodimer between TPP and (dipPhO)PcM, which is driven by the complementary shape and symmetry of the two macrocycles.

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Molecules that can reversibly switch between electronic states under an external stimulus are of interest to numerous applications. Complexes of open shell metal ions with redox active ligands undergo valence tautomerism, resulting in magnetic, colour and structural switching, relevant to data storage and actuators. However, the precise structural changes occurring during valence tautomerism in the solid state are unclear due to the lack of atomic-resolution characterization.

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Nonsymmetric 6π-electron ("oxidized") 6-oxoverdazyls have been synthesized for the first time. After formal incorporation of a hydrogen atom, the corresponding 7π-electron neutral verdazyl radical is generated. The 7π radical can undergo a further electrochemically reversible reduction to an 8π anion.

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X-ray diffraction is used to study the sorption of CO and NO in two phthalocyanine nanoporous crystals (PNCs) with 4,4' bipyridine or 4,4' bipyrimidine coordinated to open Co sites, demonstrating how the coordinated ligands influence the gas sorption properties and structures of the PNCs.

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Article Synopsis
  • A new method for preparing 1,5-dimethyl-6-thioverdazyl radicals has been developed using Lawesson's reagent, involving thionation and cyclization of specific hydrazones.
  • The efficiency of thionation varies based on the electronic nature of substituents on the substrates, with electron-withdrawing groups yielding better results.
  • The study also reports on the interactions of Lawesson's reagent with carbonyls and characterizes the electronic properties of the resulting radicals using electron paramagnetic resonance.
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Background: Intra-lenticular foreign bodies are rare in veterinary medicine and uncommon in human medicine. Approximately 50% of perforating ocular injuries in canines have lenticular involvement. Treatment choices include conservative management and surgical options.

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To develop luminescent molecular materials with predictable and stimuli-responsive emission, it is necessary to correlate changes in their geometries, packing structures, and noncovalent interactions with the associated changes in their optical properties. Here, we demonstrate that high-pressure single-crystal X-ray diffraction can be combined with high-pressure UV-visible absorption and fluorescence emission spectroscopies to elucidate how subtle changes in structure influence optical outputs. A piezochromic aggregation-induced emitter, -heptaphenylcycloheptatriene (), displays bathochromic shifts in its absorption and emission spectra at high pressure.

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Objective: To assess whether gonioscopy performed on Samoyed puppies (6-14 weeks of age) is a reliable predictor of their gonioscopy results as adults (>11 months of age).

Procedure: A retrospective medical record search was performed to identify Samoyed dogs that had undergone gonioscopy as a puppy (6-14 weeks of age). A second prospective gonioscopy examination was performed as an adult (>11 months of age) and the results were compared.

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Postsynthetic modification of metal-organic frameworks (MOFs) has proven to be a hugely powerful tool to tune physical properties and introduce functionality, by exploiting reactive sites on both the MOF linkers and their inorganic secondary building units (SBUs), and so has facilitated a wide range of applications. Studies into the reactivity of MOF SBUs have focussed solely on removal of neutral coordinating solvents, or direct exchange of linkers such as carboxylates, despite the prevalence of ancillary charge-balancing oxide and hydroxide ligands found in many SBUs. Herein, we show that the μ-OH ligands in the MIL-53 topology Sc MOF, GUF-1, are labile, and can be substituted for μ-OCH units through reaction with pore-bound methanol molecules in a very rare example of pressure-induced postsynthetic modification.

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A new high-pressure single-crystal diffraction setup has been designed and implemented at the Australian Synchrotron for collecting molecular and protein crystal structures. The setup incorporates a modified micro-Merrill-Bassett cell and holder designed specifically to fit onto the horizontal air-bearing goniometer, allowing high-pressure diffraction measurements to be collected with little to no modification of the beamline setup compared with ambient data collections. Compression data for the amino acid, L-threonine, and the protein, hen egg-white lysozyme, were collected, showcasing the capabilities of the setup.

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Background: Glaucoma is a painful and blinding condition that occurs in many species, including rabbits. When medication is no longer effective in maintaining intraocular pressure (IOP), enucleation is the recognized treatment for rabbits with end-stage glaucoma. However, this procedure carries risks relating to the procedure and the anesthesia.

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Guest-mediated pore-shape modification of the metal-organic framework, ScBDC upon adsorption of -pentane and isopentane is examined from 50-1200 bar. Rotation of the BDC linker responsible for the change in pore shape occurs at much lower pressures than previously reported, with distinct adsorption behaviour observed between pentane isomers.

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We investigate the effects of a broad array of external stimuli on the structural, spin-crossover (SCO) properties and nature of the elastic interaction within the two-dimensional Hofmann framework material [Fe(cintrz)Pd(CN)]·guest (cintrz = -cinnamalidene 4-amino-1,2,4-triazole; ·guest; guest = 3HO, 2HO, and Ø). This framework exhibits a delicate balance between ferro- and antiferro-elastic interaction characters; we show that manipulation of the pore contents across guests = 3HO, 2HO, and Ø can be exploited to regulate this balance. In ·3HO, the dominant antiferroelastic interaction character between neighboring Fe sites sees the low-temperature persistence of the mixed spin-state species {HS-LS} for {Fe1-Fe2} (HS = high spin, LS = low spin).

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The guest-dependent flexibility of the pillared-layered metal-organic framework (MOF), Znbdcdabco·(guest), where guest = EtOH, DMF or benzene, has been examined by high-pressure single crystal X-ray diffraction. A pressure-induced structural phase transition is found for the EtOH- and DMF-included frameworks during compression in a hydrostatic medium of the guest species, which is dependent upon the nature and quantity of the guest in the channels. The EtOH-included material undergoes a phase transition from 4/ to 2/ at 0.

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The synthetic viability of the hydrazine- and phosgene-free synthesis of 1,5-dimethyl oxo-verdazyl radicals has been improved a detailed study investigating the influence of the aryl substituent on tetrazinanone ring formation. Although it is well established that functionalisation at the C3 position of the tetrazinanone ring does not influence the nature of the radical, it is crucial in applications development. The synthetic route involves a 4-step sequence: Schiff base condensation of a carbohydrazide with an arylaldehyde, alkylation, ring closure then subsequent oxidation to the radical.

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single-crystal diffraction and spectroscopic techniques have been used to study a previously unreported Cu-framework bis[1-(4-pyridyl)butane-1,3-dione]copper(ii) (CuPyr-I). CuPyr-I was found to exhibit high-pressure and low-temperature phase transitions, piezochromism, negative linear compressibility, and a pressure induced Jahn-Teller switch, where the switching pressure was hydrostatic media dependent.

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Metastasis is the spread of cancer cells to a secondary site within the body, and is the leading cause of death for cancer patients. The lung is a common site of metastasis for many cancer types, including melanoma. Identifying the genes involved in aiding metastasis of melanoma cells to the lungs is critical for the development of better treatments.

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Melanoma represents ~5% of all cutaneous malignancies, yet accounts for the majority of skin cancer deaths due to its propensity to metastasise. To develop new therapies, novel target molecules must to be identified and the accessibility of cell surface proteins makes them attractive targets. Using CRISPR activation technology, we screened a library of guide RNAs targeting membrane protein-encoding genes to identify cell surface molecules whose upregulation enhances the metastatic pulmonary colonisation capabilities of tumour cells in vivo.

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Article Synopsis
  • - The study examines how halogen functionalization affects the spin crossover (SCO) properties in a family of 2-D Hofmann framework materials containing iron and palladium, focusing on versions that use chlorine and bromine.
  • - The presence of chlorine and bromine causes a blockage in the spin-state transitions due to the steric bulk from the halogen atoms and other guest molecules, although SCO can still occur with guest removal or physical pressure.
  • - Removal of water from these frameworks results in stable structures with only slight changes, while applying pressure (above 0.62 GPa) can induce SCO in the solvated forms, leading to a shift in transition temperatures among the different versions of the materials studied.
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The synthesis of the Rh(I)-aryl complex, Rh(I)(nbd)(BiPh)(P(4-FCH)) is reported and its efficacy as an initiator for the (co)polymerization of phenylacetylenes established. The X-ray crystal structure indicates that the complex adopts a slightly distorted square planar geometry whose purity and structure was also confirmed by elemental analysis and H, C, P, F, Rh, and P-Rh{H} HMQC NMR spectroscopy. We demonstrate that Rh(I)(nbd)(BiPh)(P(4-FCH)) mediates the (co)polymerization of phenylacetylenes in a controlled fashion with initiation efficiencies as high as 0.

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High-pressure single-crystal X-ray diffraction has been used to trap both the low-spin (LS) and high-spin (HS) states of the iron(II) Hofmann spin crossover framework, [Fe (pdm)(H O)[Ag(CN) ] ⋅H O, under identical experimental conditions, allowing the structural changes arising from the spin-transition to be deconvoluted from previously reported thermal effects.

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This paper reports on the acceptability, experience of participation and the immediate impact on maternal mood state of group singing sessions, introduced as a routine component of a mother-baby unit (MBU) treatment programme. Data was collected from 27 women who participated in the pilot programme. Results showed that implementation of a singing intervention in this setting is positively appraised by women and is associated with positive changes in self-reported mood state from pre- to post-session.

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With many safety and technical limitations partly mitigated through chemical modifications, antisense oligonucleotides (ASOs) are gaining recognition as therapeutic entities. The increase in potency realized by 'third generation chemistries' may, however, simultaneously increase affinity to unintended targets with partial sequence complementarity. However, putative hybridization-dependent off-target effects (OTEs), a risk historically regarded as low, are not being adequately investigated.

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