Synthesis of zeolites using the ADOR (Assembly-Disassembly-Organization-Reassembly) route

R.E.M. thanks the Royal Society and the E.P.S.R.C. (Grants EP/L014475/1, EP/K025112/1 and EP/K005499/1) for funding work in this area. J.Č. acknowledges the Czech Science Foundation for the project of the Centre of Excellence (P106/12/G015) and the European Union Seventh Framework Programme (FP7/ 2007-‐‐2013) under grant agreement n°604307.Zeolites are an important class of materials that have wide ranging applications such as heterogeneous catalysts and adsorbents which are dependent on their framework topology. For new applications or improvements to existing ones, new zeolites with novel pore systems are desirable. We demonstrate a method for the synthesis of novel zeolites using the ADOR route. ADOR is an acronym for Assembly, Disassembly, Organization and Reassembly. This synthetic route takes advantage of the assembly of a relatively poorly stable zeolite which can be selectively disassembled into a layered material. The resulting layered intermediate can then be organized in different manners by careful chemical manipulation and then reassembled into zeolites with new topologies. By carefully controlling the organization step of the synthetic pathway, new zeolites with never before seen topologies are capable of being synthesized. The structures of these new zeolites are confirmed using powder X-ray diffraction and further characterized by nitrogen adsorption and scanning electron microscopy. This new synthetic pathway for zeolites demonstrates its capability to produce novel frameworks that have never been prepared by traditional zeolite synthesis techniques.Publisher PDFPeer reviewe

Advances in organic anode materials for Na-/K-Ion rechargeable batteries

Funding: Faraday Institution (GrantNumber(s): FIRG018).Electrochemical energy storage (EES) devices are gaining ever greater prominence in the quest for global energy security. With increasing applications and widening scope, rechargeable battery technology is gradually finding avenues for more abundant and sustainable systems such as Na‐ion (NIB) and K‐ion batteries (KIB). Development of suitable electrode materials lies at the core of this transition. Organic redox‐active molecules are attractive candidates as negative electrode materials owing to their low redox potentials and the fact that they can be obtained from biomass. Also, the rich structural diversity allows integration into several solid‐state polymeric materials. Research in this domain is increasingly focused on deploying molecular engineering to address specific electrochemical limitations that hamper competition with rival materials. This Minireview aims to summarize the advances in both the electrochemical properties and the materials development of organic anode materials.Publisher PDFPeer reviewe

Crystal structure resolution of two different chlorhexidine salts

This work was partly funded by the British Heart Foundation (NH/11/8/29253) and the EPSRC (EP/K005499/1). CCDC 1416048 and 1416049 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cifTwo salts of the chlorhexidine di-cation (H2CHx2+) – (H2CHx)(SO4)·3H2O and (H2CHx)(CO3)·4H2O – have been synthesised and characterised crystallographically.Publisher PDFPeer reviewe

Synthesis and crystallographic characterisation of Mg(H2dhtp)(H2O)5·H2O

This work was funded by the British Heart Foundation (NH/11/8/29253) and the EPSRC (EP/K005499/1) (EP/K503162/1). CCDC 1432662 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.A mononuclear complex of composition Mg(H2dhtp)(H2O)5·H2O has been prepared and characterised crystallographically.PostprintPostprintPeer reviewe

Post-synthesis incorporation of Al into germanosilicate ITH zeolites : the influence of treatment conditions on the acidic properties and catalytic behavior in tetrahydropyranylation

M. S. thanks the Czech Science Foundation for support through the project 14-30898P. M. O. acknowledges the Czech Science Foundation for the project 13-17593P. R. E. M. thanks the EPSRC for funding (EP/K025112/1 and EP/L014475/1).Post-synthesis alumination of germanosilicate medium-pore ITH zeolites was shown to be an effective procedure for tuning their acidity. Treatment of ITH zeolites synthesized with different chemical compositions (i.e. Si/Ge = 2.5, 4.4 and 5.8) with aqueous Al(NO3)3 solution led to the formation of strong Brønsted and Lewis acid sites and an increasing fraction of ultramicro- and meso-pores in Ge-rich ITH samples (Si/Ge = 2.5 and 4.4). The concentration of Al incorporated into the framework increases with decreasing Si/Ge ratio of the parent ITH. The increasing temperature of alumination from 80 to 175 °C (HT conditions) resulted in (1) a 1.5-2-fold increase in the concentration of Brønsted acid sites formed and (2) a decreasing fraction of framework Al atoms detectable with base probe molecules (i.e. pyridine, 2,6-di-tert-butylpyridine), i.e. an increased concentration of the "inner" acid sites. The activity of prepared Al-substituted ITH zeolites in tetrahydropyranylation of alcohols is enhanced with increasing amount of accessible acid sites in bulky crystals (e.g. alumination at lower temperature) or with increasing total concentration of acid centres within tiny ITH crystals (e.g. alumination under HT conditions). This trend became more prominent with increasing kinetic diameter of the substrate molecules under investigation (methanol <1-propanol <1-hexanol).PostprintPeer reviewe

Following the unusual breathing behaviour of 17O-enriched mixed-metal (Al,Ga)-MIL-53 using NMR crystallography

The authors would like to thank the ERC (EU FP7 Consolidator Grant 614290 EXONMR and Advanced Grant 787073 ADOR), and EPSRC (EP/N509759/1) for a studentship for CMR. SEA would like to thank the Royal Society and Wolfson Foundation for a merit award. We acknowledge support from the Collaborative Computational Project on NMR Crystallography (CCP-NC) funded by EPSRC (EP/M022501/1) and the UKCP consortium funded by EPSRC (EP/K013564/1). For computational resources we are grateful to the UK Materials and Molecular Modelling Hub, which is partially funded by EPSRC (EP/P020194/1) and the UK HPC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202). The research data (and/or materials) supporting this publication can be accessed at DOI: https://doi.org/10.17630/31529c8b-f197-484c-929b-ef993a5bea68.69The breathing behaviour of 17O-enriched (Al,Ga)-MIL-53, a terephthalate-based metal organic framework, has been investigated using a combination of solid-state nuclear magnetic resonance (NMR) spectroscopy, powder X-ray diffraction (PXRD) and first-principles calculations. These reveal that the behaviour observed for as-made, calcined, hydrated and subsequently dehydrated mixed-metal MIL-53 materials differs with composition, but cannot be described as the compositionally weighted average of the breathing behaviour seen for the two end members. Although the form of MIL-53 adopted by the as-made material is independent of metal composition, upon calcination, materials with higher levels of Al adopt an open pore (OP) form, as found for the Al end member, but substitution of Ga results in mixed pore materials, with OP and narrow pore (NP) forms co-existing. Although the Ga end member is prone to decomposition under the calcination conditions used, a low level of Al in the starting synthesis (5%) leads to an OP mixed-metal MOF that is stable to calcination. Upon hydration all materials almost exclusively adopt a closed pore (CP) structure, with strong hydrogen bonding interactions with water leading to two distinct resonances from the carboxylate oxygens in 17O NMR spectra. When dehydrated, different framework structures are found for the two end members, OP for Al- MIL-53 and NP for Ga-MIL-53, with the proportion of NP MOF seen to increase systematically with the Ga content in mixed-metal materials, in contrast to the forms seen upon initial calcination. 17O NMR spectra of mixed-metal MIL-53 materials show an increased preference for clustering of like cations as the Ga content increases. This is not a result of the small-scale dry gel conversion reactions used for enrichment, as a similar cation distribution and clustering is also observed for (Al0.5,Ga0.5)-MIL-53 synthesised hydrothermally and enriched with 17O via post-synthetic steaming.Publisher PDFPeer reviewe

The impact of climate and antigenic evolution on seasonal influenza virus epidemics in Australia.

Although seasonal influenza viruses circulate globally, prevention and treatment occur at the level of regions, cities, and communities. At these scales, the timing, duration and magnitude of epidemics vary substantially, but the underlying causes of this variation are poorly understood. Here, based on analyses of a 15-year city-level dataset of 18,250 laboratory-confirmed and antigenically-characterised influenza virus infections from Australia, we investigate the effects of previously hypothesised environmental and virological drivers of influenza epidemics. We find that anomalous fluctuations in temperature and humidity do not predict local epidemic onset timings. We also find that virus antigenic change has no consistent effect on epidemic size. In contrast, epidemic onset time and heterosubtypic competition have substantial effects on epidemic size and composition. Our findings suggest that the relationship between influenza population immunity and epidemiology is more complex than previously supposed and that the strong influence of short-term processes may hinder long-term epidemiological forecasts

Kinetics and mechanism of the hydrolysis and rearrangement processes within the assembly-disassembly-organization-reassembly synthesis of zeolites

The authors would like to thank the EPSRC (grants: EP/K025112/1; EP/K005499/1; EP/K503162/1; EP/N509759/1) for funding opportunities. R.E.M., and M.M. would like to acknowledge OP VVV "Excellent Research Teams", project No. CZ.02.1.01/0.0/0.0/15_003/0000417 - CUCAM. We would like to thank the ERC (Advanced Grant 787073 “ADOR”).The hydrolysis (disassembly, D) and rearrangement (organization, O) steps of the assembly-disassembly-organization-reassembly (ADOR) process for the synthesis of zeolites have been studied. Germanium–rich UTL was subjected to hydrolysis conditions in water to understand the effects of temperature (100, 92, 85, 81, 77, and 70 °C). Samples were taken periodically over an 8–37 h period and each sample was analyzed by powder X-ray diffraction. The results show that the hydrolysis step is solely dependent on the presence of liquid water, whereas the rearrangement is dependent on the temperature of the system. The kinetics have been investigated using the Avrami-Erofeev model. With increasing temperature, an increase in rate of reaction for the rearrangement step was observed and the Arrhenius equation was used to ascertain an apparent activation energy for the rearrangement from the kinetic product of the disassembly (IPC-1P) to the thermodynamic product of the rearrangement (IPC-2P). From this information a mechanism for this transformation can be postulated.Publisher PDFPeer reviewe

Potreba - temeljni parametar čovjekovih aktivnosti

Dosad zanemaren kompleksni fenomen potreba, kako u teorijskim, tako i u praktičnim razmatranjima, zahtjeva nužno promjenu. Jer potreba, predstavlja i početnu i završnu točku i proizvodnje i potrošnje. Relativno je prirodom neograničen i beskonačan broj potreba koji čovjek posjeduje. Razvojem proizvodnje i humanizacijom potrošnje on se geometrijskom progresijom povećava. Ne sagledavanje ovog fenomena u svoj svojoj kompleksnosti, važnosti i dinamičnosti uzrokuje višestruke gubitke čije dimenzije su u svim svojim granicama teško sagledive. Stoga se pred ekonomsku politiku (makro i mikro) postavlja staro-novi problem čije dubinsko sagledavanje je temeljna pretpostavka ostvarivanja željenih pravaca i dinamike razvoja

Surface functionalized metal-organic frameworks for binding coronavirus proteins

This work was supported by University of St Andrews Restarting Research Funding Scheme (SARRF), funded through the SFC grant reference SFC/AN/08/020 (XRR064) and European Research Council grant ADOR (Advanced Grant 787073). The authors acknowledge the EPSRC Light Element Analysis Facility Grant (EP/T019298/1) and the EPSRC Strategic Equipment Resource Grant (EP/R023751/1).Since the outbreak of SARS-CoV-2, a multitude of strategies have been explored for the means of protection and shielding against virus particles: filtration equipment (PPE) has been widely used in daily life. In this work, we explore another approach in the form of deactivating coronavirus particles through selective binding onto the surface of metal–organic frameworks (MOFs) to further the fight against the transmission of respiratory viruses. MOFs are attractive materials in this regard, as their rich pore and surface chemistry can easily be modified on demand. The surfaces of three MOFs, UiO-66(Zr), UiO-66-NH2(Zr), and UiO-66-NO2(Zr), have been functionalized with repurposed antiviral agents, namely, folic acid, nystatin, and tenofovir, to enable specific interactions with the external spike protein of the SARS virus. Protein binding studies revealed that this surface modification significantly improved the binding affinity toward glycosylated and non-glycosylated proteins for all three MOFs. Additionally, the pores for the surface-functionalized MOFs can adsorb water, making them suitable for locally dehydrating microbial aerosols. Our findings highlight the immense potential of MOFs in deactivating respiratory coronaviruses to be better equipped to fight future pandemics.Publisher PDFPeer reviewe