Inspired by the crystal structure of a MnIII dinuclear complex we obtained featuring both Jahn-Te... more Inspired by the crystal structure of a MnIII dinuclear complex we obtained featuring both Jahn-Teller (JT) elongation and compression distortions, we have modelled a series of complex cations based on...
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Substituted [2.2]metaparacyclophanes are amongst the least studied of the simple cyclophanes. Thi... more Substituted [2.2]metaparacyclophanes are amongst the least studied of the simple cyclophanes. This is undoubtedly the result of the lengthy syntheses of these compounds. We report the simple synthesis of a rare example of a non-symmetric [2.2]metaparacyclophane. Treatment of [2.2]paracyclophane under standard nitration conditions gives a mixture of 4-nitro[2.2]paracyclophane, 4-hydroxy-5-nitro[2.2]metaparacyclophane and a cyclohexadienone cyclophane.
9Be solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. A... more 9Be solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. An updated comprehensive table of the 9Be NMR chemical shifts of beryllium complexes in solution is presented. The recent additions span a greater range of chemical shifts than those previously reported, and more overlap is observed between the chemical shift regions of four-coordinate complexes and those with lower coordination numbers. Four-coordinate beryllium species have smaller ω 1/2 values than the two- and three-coordinate species due to their higher order symmetry. In contrast to previous studies, no clear relationship is observed between chemical shift and the size and number of chelate rings.
Advances in nanotechnology have resulted in the introduction of magnetic fluid hyperthermia (MFH)... more Advances in nanotechnology have resulted in the introduction of magnetic fluid hyperthermia (MFH), a promising noninvasive therapeutic localized cancer treatment. Exposure of a fluid of superparamagnetic iron oxide nanoparticles (IONPs) to an alternating magnetic field (AMF) operating at biologically benign conditions leads to heat dissipation within the tumor and ultimate apoptosis and/or necrosis. Despite use in a clinical setting, there are still impediments preventing widespread use of MFH. These include insufficient heat dissipation potency of IONP fluid, inadequate dose or concentration of deposited fluid to the tumor, inhomogeneous distribution of fluid inside the tumor, the lack of control of real‐time monitoring of temperature rises during treatment, and exposure of the patients to X‐ray radiation produced by computed tomography (CT) scans. Accordingly, massive efforts have been put forth to promote the successful clinical adoption of MFH. In this contribution, the technique of MFH is described, including the present state of clinical MFH. The physical mechanisms behind heat dissipation by magnetic nanoparticles (MNPs) that instigate cell death pathways are discussed, as is recent technological progress in the field toward the advancement of MFH. Finally, an outlook on the future considerations required to accelerate the clinical adoption of MFH is presented.
Abstract In this study we compared the heat resistance of spores of G. stearothermophilus A1, D1,... more Abstract In this study we compared the heat resistance of spores of G. stearothermophilus A1, D1, P3 and ATCC 12980 obtained using the milk biofilm system under continuous flow with previously reported values obtained by a sporulating medium. The average decimal reduction times of A1, D1, P3 and ATCC 12980 were 4.2, 4.9, 4.1 and 7.9 min, respectively, and were not significantly different (p
Secondary-sphere H-bonding is shown to strengthen the binding of tetra-dentate pyridyl-derived li... more Secondary-sphere H-bonding is shown to strengthen the binding of tetra-dentate pyridyl-derived ligands towards beryllium.
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2019
Catalysis is an important process across multiple disciplines, and there are still many challenge... more Catalysis is an important process across multiple disciplines, and there are still many challenges to be met. Enzymes, “nature’s catalysts”, display impressive efficacy with controlled selectivity and rapid throughput, so attempting to mimic these properties opens up exciting pathways in catalyst research. In recent years, metallo-organic coordination cages have shown promise in exploring these avenues. Their unique structures and modifiable properties present opportunities not available to traditional catalysts. This mini-review provides a general introduction to the field, then attempts to extract effects ascribed to interior versus surface or exterior influences, illustrating these with recently published results.
In this paper, we present our findings on a series of copper(ii) 2,2′-bipyridyl (bipy) complexes ... more In this paper, we present our findings on a series of copper(ii) 2,2′-bipyridyl (bipy) complexes that inhibit the oxidation of thiosulfate, a current problem in the gold leaching process. The formation of six complexes, five of which have been structurally characterized by X-ray crystallography, illustrate a thermally induced, controllable switching between oxidation states, which in turn inhibits the oxidation of thiosulfate. These findings give further insight and understanding into the rich chemistry of the coinage metals and the hydrolytic processes involved with gold leaching.
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2019
We report an improved method to make the ligand N,N′-(pyrazine-2,5-diylbis(methanylylidene))bis(2... more We report an improved method to make the ligand N,N′-(pyrazine-2,5-diylbis(methanylylidene))bis(2-(pyridin-2-yl)ethanamine) (L) and the subsequent complexation of this ligand to make the triangular metallo-macrocycles [Co3L3](ClO4)6·2H2O (C1·2H2O) and [Mn3L3](ClO4)6·3H2O (C2·3H2O). Single crystal X-ray analysis of both trimeric circular helicates reveal the complexes pack in enantiomeric pairs in close synergy with the accompanying anions.Graphical abstract
Inspired by the crystal structure of a MnIII dinuclear complex we obtained featuring both Jahn-Te... more Inspired by the crystal structure of a MnIII dinuclear complex we obtained featuring both Jahn-Teller (JT) elongation and compression distortions, we have modelled a series of complex cations based on...
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Substituted [2.2]metaparacyclophanes are amongst the least studied of the simple cyclophanes. Thi... more Substituted [2.2]metaparacyclophanes are amongst the least studied of the simple cyclophanes. This is undoubtedly the result of the lengthy syntheses of these compounds. We report the simple synthesis of a rare example of a non-symmetric [2.2]metaparacyclophane. Treatment of [2.2]paracyclophane under standard nitration conditions gives a mixture of 4-nitro[2.2]paracyclophane, 4-hydroxy-5-nitro[2.2]metaparacyclophane and a cyclohexadienone cyclophane.
9Be solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. A... more 9Be solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. An updated comprehensive table of the 9Be NMR chemical shifts of beryllium complexes in solution is presented. The recent additions span a greater range of chemical shifts than those previously reported, and more overlap is observed between the chemical shift regions of four-coordinate complexes and those with lower coordination numbers. Four-coordinate beryllium species have smaller ω 1/2 values than the two- and three-coordinate species due to their higher order symmetry. In contrast to previous studies, no clear relationship is observed between chemical shift and the size and number of chelate rings.
Advances in nanotechnology have resulted in the introduction of magnetic fluid hyperthermia (MFH)... more Advances in nanotechnology have resulted in the introduction of magnetic fluid hyperthermia (MFH), a promising noninvasive therapeutic localized cancer treatment. Exposure of a fluid of superparamagnetic iron oxide nanoparticles (IONPs) to an alternating magnetic field (AMF) operating at biologically benign conditions leads to heat dissipation within the tumor and ultimate apoptosis and/or necrosis. Despite use in a clinical setting, there are still impediments preventing widespread use of MFH. These include insufficient heat dissipation potency of IONP fluid, inadequate dose or concentration of deposited fluid to the tumor, inhomogeneous distribution of fluid inside the tumor, the lack of control of real‐time monitoring of temperature rises during treatment, and exposure of the patients to X‐ray radiation produced by computed tomography (CT) scans. Accordingly, massive efforts have been put forth to promote the successful clinical adoption of MFH. In this contribution, the technique of MFH is described, including the present state of clinical MFH. The physical mechanisms behind heat dissipation by magnetic nanoparticles (MNPs) that instigate cell death pathways are discussed, as is recent technological progress in the field toward the advancement of MFH. Finally, an outlook on the future considerations required to accelerate the clinical adoption of MFH is presented.
Abstract In this study we compared the heat resistance of spores of G. stearothermophilus A1, D1,... more Abstract In this study we compared the heat resistance of spores of G. stearothermophilus A1, D1, P3 and ATCC 12980 obtained using the milk biofilm system under continuous flow with previously reported values obtained by a sporulating medium. The average decimal reduction times of A1, D1, P3 and ATCC 12980 were 4.2, 4.9, 4.1 and 7.9 min, respectively, and were not significantly different (p
Secondary-sphere H-bonding is shown to strengthen the binding of tetra-dentate pyridyl-derived li... more Secondary-sphere H-bonding is shown to strengthen the binding of tetra-dentate pyridyl-derived ligands towards beryllium.
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2019
Catalysis is an important process across multiple disciplines, and there are still many challenge... more Catalysis is an important process across multiple disciplines, and there are still many challenges to be met. Enzymes, “nature’s catalysts”, display impressive efficacy with controlled selectivity and rapid throughput, so attempting to mimic these properties opens up exciting pathways in catalyst research. In recent years, metallo-organic coordination cages have shown promise in exploring these avenues. Their unique structures and modifiable properties present opportunities not available to traditional catalysts. This mini-review provides a general introduction to the field, then attempts to extract effects ascribed to interior versus surface or exterior influences, illustrating these with recently published results.
In this paper, we present our findings on a series of copper(ii) 2,2′-bipyridyl (bipy) complexes ... more In this paper, we present our findings on a series of copper(ii) 2,2′-bipyridyl (bipy) complexes that inhibit the oxidation of thiosulfate, a current problem in the gold leaching process. The formation of six complexes, five of which have been structurally characterized by X-ray crystallography, illustrate a thermally induced, controllable switching between oxidation states, which in turn inhibits the oxidation of thiosulfate. These findings give further insight and understanding into the rich chemistry of the coinage metals and the hydrolytic processes involved with gold leaching.
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2019
We report an improved method to make the ligand N,N′-(pyrazine-2,5-diylbis(methanylylidene))bis(2... more We report an improved method to make the ligand N,N′-(pyrazine-2,5-diylbis(methanylylidene))bis(2-(pyridin-2-yl)ethanamine) (L) and the subsequent complexation of this ligand to make the triangular metallo-macrocycles [Co3L3](ClO4)6·2H2O (C1·2H2O) and [Mn3L3](ClO4)6·3H2O (C2·3H2O). Single crystal X-ray analysis of both trimeric circular helicates reveal the complexes pack in enantiomeric pairs in close synergy with the accompanying anions.Graphical abstract
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Papers by Paul Plieger