Final Report Summary - NEWQDS (New Frontiers in Quantum Dots Science: Assembly and Functionalisation)
Since March 2011, the Cronin group has provided state-of-the-art research facilities for the researcher and a range of new projects linking synthesis, application and diagnostics were started exploiting the critical mass of the Glasgow group. Major breakthrough aroused from this fellowship include:
(a) supramolecular assembly between Zn-S molecular clusters and lipid bilayers has been observed and this observation shed light on developing new type of membrane / lipid bilayer phase state probe;
(b) taking a significant step toward the complete understanding of the mechanism behind the photocatalytic process of metal ions in presence of porphyrinic-POMs (P-POMs) clusters;
(c) maintaining and advancing capabilities in material characterisation of 'crystalline alloys of polyoxometalates' to address the major technological challenges facing material science.
(a) Crystalline molecular clusters play an important role in biological applications of direct relevance to many aspects in our daily lives, such as bio-labelling and -sensing. Design and fabrication of crystalline chalcogenide clusters in a cost-effective and feasible way and explore their biological application is thus an important topic.
Based on the initial results that published by the researcher (Inorg. Chem., 2010, 49(4), 1319-1321; Cryst Growth Des., 2011, 11(1), 16 - 20), the observation in University of Glasgow unveiled a dynamic supramolecular self-assembly process between molecular Zn-S clusters and lipid bilayer, i.e. the assembly and disassembly process of DC15PC SLB in distinct gel and fluid phases in the presence of neutral cluster Zn8S(SC6H5)14[3-H2NC9H6N]2 has been investigated, and this process on DC15PC SLB is reversible with temperature and resonant with the fluid-gel transition, suggesting the assembly critically relies on the fluidity and mobility of lipid bilayers.
Moreover, the observed aggregation appears to result from the adsorbed Zn-S nanoclusters at the SLB interface, and possibly consists of the Zn-S clusters and lipid complexes. It should be noted that this aggregation is clearly distinct from Zn-S-free SLB or lipid unilamellar vesicle (liposome). The Zn-S added SLB is observed to maintain its integrity without showing any apparent morphological disruption, such as nanocolloid-induced pore formation and phase transition as reported in other nanocolloid-added lipid membranes.
Intriguingly, the measured area of aggregates exhibits an increase at early stage and then a decrease with time, suggesting a dissipative assembly process of Zn-S-lipid complexes. This improved understanding of dissipative self-assembly could allow us to develop a new type of membrane / lipid bilayer phase state probe.
(b) One of the major challenges for the use of crystalline polyoxometalate clusters as catalysts is their chemical and structural stability. In the pursuit of stable catalysts, porphyrinic polyoxometalate hybrid material: {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5.(CH3CN)2 has been successfully synthesised and it shown high structural robustness. TGA analysis results shown this hybrid material is thermal stable up to 476 C and most interestingly, the lattice solvent molecules could be removed upon heating at 110 C for 12 hours (with vacuum) to obtain {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5. The crystallinity of {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5 could be retained when it has been immersed in different organic solvents such as acetone, ethanol for more than three days and satisfied single crystal X-ray diffraction data could still be acquired afterwards, further demonstrated the high thermal stability of this compound. So it is anticipated that more porphyrinic polyoxometalate (P-POMs) hybrid materials with high thermal stability could be achieved. For practical applications, the photocatalytic activity of porphyrinic polyoxometalate (P-POMs) hybrid material has been explored to achieve Au nanosheets / Ag nanoparticles and to degrade Parafuchsin Hydrochloride dye molecule. It also shows scavenging activity for a series of organic dye molecules. This is shown by the change of the ultraviolet (UV)-visible spectrum of Parafuchsin Hydrochloride solution with {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5.(CH3CN)2 under illumination in 10 hours.
The observations verified the starting hypothesis that the porphyrinic-POMs (P-POMs) clusters could be used for photocatalysis application, present them as a series of promising multifunctional materials.
(c) The Cronin group had made important inroads into polyoxometalates (POMs) and the research to date shows the need to investigate more diverse range of cluster anions. Inspired by the concept of 'molecular alloy' and with the aim for the emergent bulk properties, we embarked on the research of new 'crystalline alloys of polyoxometalates'.
'Crystalline alloys of polyoxometalates' are custom-designed materials based on new advances in synthetic inorganic chemistry, with potential applications in photovoltaics, batteries and dual catalysis (more or less). Access to the different set of mixtures of classic Keggin-type polyoxometalate clusters has been realised through different synthetic strategies. Following inorganic synthesis in solid / or solution phase, multicomponent clusters are formed to create different species such as 'physical mixtures', 'chemical mixtures', 'atomic mixtures' and 'molecular mixtures'.
The initial research in the field of 'crystalline alloys of polyoxometalates' has revealed some underneath mechanism, provided highly reproducible synthetic protocols, and thus inspire other researchers to develop new 'crystalline alloys of polyoxometalates'.
(a) supramolecular assembly between Zn-S molecular clusters and lipid bilayers has been observed and this observation shed light on developing new type of membrane / lipid bilayer phase state probe;
(b) taking a significant step toward the complete understanding of the mechanism behind the photocatalytic process of metal ions in presence of porphyrinic-POMs (P-POMs) clusters;
(c) maintaining and advancing capabilities in material characterisation of 'crystalline alloys of polyoxometalates' to address the major technological challenges facing material science.
(a) Crystalline molecular clusters play an important role in biological applications of direct relevance to many aspects in our daily lives, such as bio-labelling and -sensing. Design and fabrication of crystalline chalcogenide clusters in a cost-effective and feasible way and explore their biological application is thus an important topic.
Based on the initial results that published by the researcher (Inorg. Chem., 2010, 49(4), 1319-1321; Cryst Growth Des., 2011, 11(1), 16 - 20), the observation in University of Glasgow unveiled a dynamic supramolecular self-assembly process between molecular Zn-S clusters and lipid bilayer, i.e. the assembly and disassembly process of DC15PC SLB in distinct gel and fluid phases in the presence of neutral cluster Zn8S(SC6H5)14[3-H2NC9H6N]2 has been investigated, and this process on DC15PC SLB is reversible with temperature and resonant with the fluid-gel transition, suggesting the assembly critically relies on the fluidity and mobility of lipid bilayers.
Moreover, the observed aggregation appears to result from the adsorbed Zn-S nanoclusters at the SLB interface, and possibly consists of the Zn-S clusters and lipid complexes. It should be noted that this aggregation is clearly distinct from Zn-S-free SLB or lipid unilamellar vesicle (liposome). The Zn-S added SLB is observed to maintain its integrity without showing any apparent morphological disruption, such as nanocolloid-induced pore formation and phase transition as reported in other nanocolloid-added lipid membranes.
Intriguingly, the measured area of aggregates exhibits an increase at early stage and then a decrease with time, suggesting a dissipative assembly process of Zn-S-lipid complexes. This improved understanding of dissipative self-assembly could allow us to develop a new type of membrane / lipid bilayer phase state probe.
(b) One of the major challenges for the use of crystalline polyoxometalate clusters as catalysts is their chemical and structural stability. In the pursuit of stable catalysts, porphyrinic polyoxometalate hybrid material: {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5.(CH3CN)2 has been successfully synthesised and it shown high structural robustness. TGA analysis results shown this hybrid material is thermal stable up to 476 C and most interestingly, the lattice solvent molecules could be removed upon heating at 110 C for 12 hours (with vacuum) to obtain {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5. The crystallinity of {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5 could be retained when it has been immersed in different organic solvents such as acetone, ethanol for more than three days and satisfied single crystal X-ray diffraction data could still be acquired afterwards, further demonstrated the high thermal stability of this compound. So it is anticipated that more porphyrinic polyoxometalate (P-POMs) hybrid materials with high thermal stability could be achieved. For practical applications, the photocatalytic activity of porphyrinic polyoxometalate (P-POMs) hybrid material has been explored to achieve Au nanosheets / Ag nanoparticles and to degrade Parafuchsin Hydrochloride dye molecule. It also shows scavenging activity for a series of organic dye molecules. This is shown by the change of the ultraviolet (UV)-visible spectrum of Parafuchsin Hydrochloride solution with {H8[C40H26N8]3}{[SiW12O40]2}.(H2O)5.(CH3CN)2 under illumination in 10 hours.
The observations verified the starting hypothesis that the porphyrinic-POMs (P-POMs) clusters could be used for photocatalysis application, present them as a series of promising multifunctional materials.
(c) The Cronin group had made important inroads into polyoxometalates (POMs) and the research to date shows the need to investigate more diverse range of cluster anions. Inspired by the concept of 'molecular alloy' and with the aim for the emergent bulk properties, we embarked on the research of new 'crystalline alloys of polyoxometalates'.
'Crystalline alloys of polyoxometalates' are custom-designed materials based on new advances in synthetic inorganic chemistry, with potential applications in photovoltaics, batteries and dual catalysis (more or less). Access to the different set of mixtures of classic Keggin-type polyoxometalate clusters has been realised through different synthetic strategies. Following inorganic synthesis in solid / or solution phase, multicomponent clusters are formed to create different species such as 'physical mixtures', 'chemical mixtures', 'atomic mixtures' and 'molecular mixtures'.
The initial research in the field of 'crystalline alloys of polyoxometalates' has revealed some underneath mechanism, provided highly reproducible synthetic protocols, and thus inspire other researchers to develop new 'crystalline alloys of polyoxometalates'.