Catalytic constructive deoxygenation of lignin-derived phenols: new C-C bond formation processes from imidazole-sulfonates and ether cleavage reactions

Funding: UK Engineering and Physical Sciences Research Council (EPSRC)As part of a programme aimed at exploiting lignin as a chemical feedstock for less oxygenated fine chemicals, several catalytic C-C bond forming reactions utilising guaiacol imidazole sulfonate are demonstrated. These include the cross-coupling of a Grignard, a non-toxic cyanide source, a benzoxazole, and nitromethane. A modified Meyers reaction is used to accomplish a second constructive deoxygenation on a benzoxazole functionalised anisole.Publisher PDFPeer reviewe

Greenough region catchment appraisal

This report discusses a range of options for the Greenough region, which is comprised of eight shires including the Shires of Northampton, Chapman Valley, Mullewa, Greenough, Morawa, Irwin, Mingenew and Three Springs, and also the city of Geraldton. A range of options for reducing land degradation is discussed. Factors such as soil type, annual rainfall, enterprise mix and financial structure are also considered

Benzylammonium hepta-noate-hepta-noic acid (1/1).

The title salt, C7H10N(+)·C7H13O2(-)·C7H14O2, is an unusual 2:1 stoichiometric combination of two carb-oxy-lic acid mol-ecules and one amine. Although there are crystal structures of a number of 1:1 complexes reported in the literature, 2:1 acid amine complexes are rather uncommon. In this case, a proton is transferred between one acid mol-ecule and the amine to give an acid anion and an ammonium cation whilst the other carb-oxy-lic acid remains protonated. The species inter-act strongly via electrostatic forces and hydrogen bonds. In addition we note that the N atom of the ammonium group makes four close contacts to surrounding O atoms. Three of these are hydrogen bonds with neighbouring acid anions while the fourth does not involve a hydrogen atom but is directed towards the carbonyl O atom of the protonated acid. Each of the acid anion O atoms accepts two hydrogen bonds from adjacent N atoms. There is also evidence of short C-H⋯O contacts. There is disorder (occupancy ratio 0.51:0.49) in the alkyl chain of one of the carb-oxy-lic acid mol-ecules.This work was supported by the Department of Chemistry, the BP Institute and the Oppenheimer Trust

Spatial variation in the sedimentary architecture of a dryland fluvial system

Research Funding Natural Environment Research Council (NERC). Grant Number: NEM00578X/1 British Geological Survey (BGS)Peer reviewedPublisher PD

2D constraint modifies packing behaviour: a halobenzene monolayer with X3 halogen-bonding motif.

Using a combination of X-ray diffraction and simulation techniques, we are able to identify a crystalline monolayer of 1,3,5-triiodotrifluorobenzene formed on graphite. The monolayer is found to exhibit an incommensurate hexagonal unit cell with a lattice parameter of 9.28(7) Å, exhibiting a trigonal arrangement of iodine atoms not found in the bulk structure. DFT simulations have been performed exhibiting close agreement with the experimental structure. Importantly these simulations can be used to compare the strength of the intermolecular interactions both with and without Van der Waals corrections. Thus it is possible to estimate that halogen bonding consists of approximately half the total interaction energy. This demonstrates that despite the presence of strong directional non-covalent bonding, dispersion interactions account for a very significant proportion of the total energy

Using Neutron Reflectometry to Discern the Structure of Fibrinogen Adsorption at the Stainless Steel/Aqueous Interface.

Neutron reflectometry has been successfully used to study adsorption on a stainless steel surface by means of depositing a thin steel film on silicon. The film was characterized using XPS (X-ray photoelectron spectroscopy), TOF-SIMS (time-of-flight secondary ion mass spectrometry), and GIXRD (grazing incidence X-ray diffraction), demonstrating the retention both of the austenitic phase and of the required composition for 316L stainless steel. The adsorption of fibrinogen from a physiologically-relevant solution onto the steel surface was studied using neutron reflectometry and QCM (quartz crystal microbalance) and compared to that on a deposited chromium oxide surface. It was found that the protein forms an irreversibly bound layer at low concentrations, with maximum protein concentration a distance of around 20 Å from the surface. Evidence for a further diffuse reversibly-bound layer forming at higher concentrations was also observed. Both the structure of the layer revealed by the neutron reflectometry data and the high water retention predicted by the QCM data suggest that there is a significant extent of protein unfolding upon adsorption. A lower extent of adsorption was seen on the chromium surfaces, although the adsorbed layer structures were similar, suggesting comparable adsorption mechanisms.M.H.W. is grateful to the Oppenheimer Trust for funding.This is the author accepted manuscript. The final version is available from the American Chemical Socitey via http://dx.doi.org/10.1021/acs.jpcb.6b0234

Phenolic profile and content of sorghum grains under different irrigation managements

Sorghum grain is widely consumed in Sub-Saharan Africa and Asia, as a staple food due to its adaptation to harsh environments. The impact of irrigation regime: full irrigation (100%); deficit irrigation (50%); and severe deficit irrigation (25%) on phenolic profile and content of six sorghum grain genotypes was investigated by high performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS). A total of 25 individual polyphenols were unequivocally or tentatively identified. Compared to the colored-grain genotypes, the white grained sorghum var. Liberty had a simpler polyphenol profile. The concentrations of the sorghum-specific 3-deoxyanthocyanidins luteolinidin and apigeninidin, were higher under deficit irrigation compared to the other two regimes in all genotypes. These findings will be valuable for the selection of sorghum genotypes for grain production as human food under water deficit conditions, since polyphenol levels can affect the grain's nutritional value and health properties

Comparative Adsorption of Saturated and Unsaturated Fatty Acids at the Iron Oxide/Oil Interface.

A detailed comparison of the adsorption behavior of long straight chain saturated and unsaturated fatty acids at the iron oxide/oil interface has been considered using a combination of surface study techniques. Both depletion isotherms and polarized neutron reflectometry (PNR) show that the extent of adsorption decreases as the number of double bonds in the alkyl chains increases. Sum frequency generation spectroscopic measurements demonstrate that there is also an increase in chain disorder within the adsorbed layer as the unsaturation increases. However, for the unsaturated analogues, a decrease in peak intensity is seen for the double bond peak upon heating, which is thought to arise from isomerization in the surface-bound layer. The PNR study of oleic acid adsorption indicates chemisorbed monolayer adsorption, with a further diffuse reversible adsorbed layer formed at higher concentrations.Mary Wood is grateful for funding from the Oppenheimer Trust. The PNR data were collected using the V6 instrument at the Helmholtz-Zentrum Berlin (experiment number MAT-04-2131).This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/acs.langmuir.5b0443

Adsorption behaviour of the binary mixtures of octane and nonane at sub-monolayer coverage on graphite

The behaviour of binary mixtures of octane and nonane adsorbed on graphite has been investigated with a combination of adiabatic calorimetry and neutron di†raction. In contrast to the eutectic behaviour of monolayers of these materials at higher coverages, this combination of alkanes is found to form mixed crystals on the surface over an extensive composition range at the sub-monolayer coverages investigated here. In the mixed phase the shorter octane molecules are incorporated into the lattice of the longer nonane molecules. This incorporation occurs despite pure octane and nonane monolayers having di†erent symmetries and is attributed to the expanded nature of the submonolayer phases, relative to higher coverage monolayers, providing room for mixed crystal formation