Sharon E. Ashbrook’s research while affiliated with University of St Andrews and other places

... Nuclear magnetic resonance (NMR) is widely used to probe the local atomic structure of materials and molecules 1 , making it suitable to study static [2][3][4] and dynamic [5][6][7] properties of chemical systems. Several interactions affecting nuclear spins are orientation-dependent, but they are usually averaged due to rapid tumbling, e.g., in liquid-state NMR on molecules. ...

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Graph-neural-network predictions of solid-state NMR parameters from spherical tensor decomposition

... [38][39][40] More challengingly, most of the known SO 2adsorbing MOFs are hydrophilic in nature, as the preferable adsorption sites for SO 2 , including open metal sites (OMSs) and Lewis basic sites, also exhibit a high affinity for water. In view of the low concentration of SO 2 in flue gas, a significant adsorption of H 2 O lowering the SO 2 uptake would severely reduce the requisite high adsorption selectivity of SO 2 over other gas components (mostly N 2 , CO 2 , and O 2 ), as exemplified by MOF-74 series [41,42] and KAUST-7. [43] Conversely, although hydrophobic MOFs could intrinsically avoid the negative impacts of water vapor, they might suffer from poor SO 2 capture capacity and leave a large amount of water in flue gas, which will continue to be detrimental to adsorbents for CO 2 scrubbing (e.g., CALF-20) and corrosive to pipeline systems for transport. ...

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A Hydrolytically Stable Metal–Organic Framework for Simultaneous Desulfurization and Dehydration of Wet Flue Gas

... In Ca-doped Na 3 PS 4 , a higher energy barrier but faster Na + kinetics are required for localized Na + jumps. 18 In this study, (100−x)Na 3 PS 4 −xCa 3 N 2 glass SEs (0 ≤ x ≤ 10) were successfully synthesized using highenergy planetary ball-milling method. The glass SE was heat-treated at 280 • C for 1 h in an argon atmosphere to obtain glass-ceramic SE. ...

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Na conductivity of (100−x)Na3PS4−xCa3N2 glass and glass−ceramics

... This process contributes to the creation of a sustainable and renewable energy market, yielding economic benefits and supporting decarbonization efforts [56,57]. Davidson et al. [58] developed an lignin isolation method with organosolv that delivered important practical improvements, and mentioned that, for CPH biomass, novel protocol was very useful. ...

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The potential of cacao pod husk for sustainable packaging: A comprehensive review and future prospects

... This would seem to prohibit a dissolution and recrystallisation mechanism and suggests that metathesis (at least in these examples) occurs by localised bond-breaking/regeneration mechanisms that maintain the lattice architecture. While typically affected in solvent under mild conditions, linker exchange has been demonstrated in the vapour phase [138] and recently, quantitative and reversible exchange of µ 2 -OH for in-situ generated methoxide at a Sc III MOF node was observed under ultra high pressure (4.98 GPa) [139]. We do not intend to provide a comprehensive review of ion and ligand metathesis here but rather to provide commentary on these processes from the perspective of dynamic bonding. ...

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The role of dynamic metal-ligand bonds in metal-organic framework chemistry

... As such, given a kinetically allowed pathway, rearrangement of Al and Ga at the elevated temperature of calcination could lead to a more random distribution of cations than observed in the as-made materials. However, we note that the mechanism(s) exploited by Ashbrook and co-workers [36][37][38][39] involve the presence of H 2 O, which would be chemically unlikely under our hightemperature calcination conditions. ...

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Site-Directed Cation Ordering in Chabazite-Type AlxGa1–xPO4-34 Frameworks Revealed by NMR Crystallography

... [26][27][28][29][30] Recent papers also report investigations of spincrossover systems and particularly their applications. [31][32][33][34][35][36] Adjacent to the topic, related spin equilibrium systems have been studied computationally using DFT and Boltzmann statistics by Ke et al. 37,38 with the high-spin and low-spin configurations arising from two distinct paramagnetic centers. In this work, we examine the significance of the spin-crossover effect in predicting the pNMR chemical shifts in an isolated Tp 2 Fe(II) molecule, and how different computational fitting methods for handling its equilibrium state succeed in reproducing the experimental results. ...

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Computational NMR of the iron pyrazolylborate complexes [Tp 2 Fe] + and Tp 2 Fe including solvation and spin-crossover effects

... They belong to a B−O−B bond, proving successful introduction of some O elements. 31 In the meanwhile, the broad and weak peak at a wavenumber of 3400 cm −1 in the spectrum of commercial h-BN is the absorption of a −OH vibration, which may be caused by surface adhesion of water in the air. 32 However, the absence of peaks at the same position in prepared h-BN powders not only indicates complete removal of surface adsorption after high-temperature synthesis but also clarifies that the edges of the nanosheet are free of −OH functionalization, which is another indistinguishable and undesirable O doping form. ...

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Preparation of Thin-Layered Hexagonal Boron Nitride Nanosheet with Oxygen Doping

... However, 17 O has a low natural abundance of 0.037% and is a spin-5/2 quadrupolar nucleus, which results in poor NMR sensitivity and necessitates isotopic enrichment. 17 O labeling of zeolitic materials has seen renewed interest recently with the introduction of several isotopic enrichment strategies [67][68][69][70] . Morris, Ashbrook, and co-workers recently showed that a uniform 17 O enrichment of zeolitic frameworks could be achieved by mixing dehydrated zeolites with H 2 17 O at room temperature for a few days 69,71 . ...

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Defects tune the acidic strength of amorphous aluminosilicates

... Chem. with 14 publications on various quadrupolar nuclei [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. ...

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An Introductory Lecture Course on Solid-State NMR Spectroscopy