VerSoX B07-B: a high-throughput XPS and ambient pressure NEXAFS beamline at Diamond Light Source.

The beamline optics and endstations at branch B of the Versatile Soft X-ray (VerSoX) beamline B07 at Diamond Light Source are described. B07-B provides medium-flux X-rays in the range 45-2200 eV from a bending magnet source, giving access to local electronic structure for atoms of all elements from Li to Y. It has an endstation for high-throughput X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) measurements under ultrahigh-vacuum (UHV) conditions.

Shape controlled assembly of carboxylic acids: formation of a binary monolayer by intercalation into molecular nanotunnels.

Binary self-assembled monolayers (SAMs) combining a Y-shaped aromatic carboxylic acid (1,3,5-benzenetribenzoic acid, H3BTB) and a cage-type alicyclic carboxylic acid (adamantane carboxylic acid, AdCA) were investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The SAMs, prepared by molecular adsorption from solution on Au substrates modified by underpotential deposition of Ag, exhibit a pronounced dependence of their structure on the assembly protocol. Exposing an H3BTB SAM to AdCA, the highly regular row structure of the native H3BTB layer persists and STM imaging does not show signs of AdCA adsorption.

On-surface condensation of low-dimensional benzotriazole-copper assemblies.

The reactivity of benzotriazole with copper on a gold surface has been studied by a combination of surface sensitive methods with support from DFT (density functional theory) calculations. For some time benzotriazole has been known to enhance the corrosion resistance of copper at the monolayer level, although the exact mechanism is still a matter of discussion and disagreement in the literature. A single crystal Au(111) surface allows evaluation of the interaction of weakly physisorbed, intact benzotriazole molecules with copper atoms dosed to sub-monolayer amounts.

Self-Assembly of Di(pyrazol-1-yl)pyridine-benzoic Acid on Underpotentially Deposited Ag from Solution.

Monolayers of 4-(2,6-di(1 H-pyrazol-1-yl)pyridine-4-yl)benzoic acid (DPP-BA) on Au substrates modified by an underpotential-deposited bilayer of Ag were studied by X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy, and scanning tunneling microscopy. Highly crystalline layers are formed with molecules coordinatively bonding to the surface through the carboxylate moiety in a bidentate configuration. The molecules assemble to rows characterized by densely packed upright-orientated DPP units occupying an area of 41 Å.

Synthesis of ZIF-93/11 Hybrid Nanoparticles via Post-Synthetic Modification of ZIF-93 and Their Use for H /CO Separation.

The present work shows the synthesis of nano-sized hybrid zeolitic imidazolate frameworks (ZIFs) with the rho topology based on a mixture of the linkers benzimidazole (bIm) and 4-methyl-5-imidazolecarboxaldehyde (4-m-5-ica). The hybrid ZIF was obtained by post-synthetic modification of ZIF-93 in a bIm solution. The use of different solvents, MeOH and N,N-dimethylacetamide (DMAc), and reaction times led to differences in the quantity of bIm incorporated to the framework, from 7.

Biochemical and functional characterization of glycosaminoglycans released from degranulating rat peritoneal mast cells: Insights into the physiological role of endogenous heparin.

The properties of commercially prepared heparin as an anticoagulant and antithrombotic agent in medicine are better understood than is the physiological role of heparin in its native form, where it is uniquely found in the secretory granules of mast cells. In the present study we have isolated and characterised the glycosaminoglycans (GAGs) released from degranulating rat peritoneal mast cells. Analysis of the GAGs by NMR spectroscopy showed the presence of both heparin and the galactosaminoglycan dermatan sulphate; heparinase digestion profiles and measurements of anticoagulant activity were consistent with this finding.

Formation of bioinorganic complexes by the corrosive adsorption of (S)-proline on Ni/Au(111).

Nickel nanoparticles modified by the adsorption of chiral amino acids are known to be effective enantioselective heterogeneous catalysts. The leaching of nickel by amino acids has a number of potential effects including the induction of chirality in the nickel atoms left behind in the nanoparticle and the creation of catalytically active nickel complexes. The adsorption of (S)-proline onto Au(111) precovered by two-dimensional nickel nanoclusters was investigated by scanning tunneling microscopy, X-ray photoelectron spectroscopy, and high-resolution electron energy loss spectroscopy.

Adsorption of a dihydro-TTF derivative on Au(111) via a thiolate complex bonding to gold adatoms.

A dihydro-TTF derivative with four acetyl-protected thiol ligands was synthesised and adsorbed on Au(111) under UHV conditions. Scanning Tunnelling Microscopy (STM) and Infrared (IR) spectroscopy show that self-organised structures are formed following annealing to 333 K, with each pair of bidentate thiolate ligands bonding to a single gold adatom in a S-Auad-S complex. Due to the lack of a direct orbital overlap between the dihydro-TTF moieties and the surface, relatively little charge transfer between TAT-TTF and the gold surface occurs.

Assembly of a chiral amino acid on an unreactive surface: (S)-proline on Au(111).

The adsorption of (S)-proline on Au(111) at 300 K was studied by low-temperature scanning tunnelling microscopy, X-ray photoelectron spectroscopy, and high resolution electron energy loss spectroscopy. (S)-proline adsorbs to produce a 2-D gas phase at 300 K, which can be condensed to form ordered molecular assemblies on cooling to 77 K. The chemical nature of the self-assembled structures is discussed in light of the information provided by photoelectron and vibrational spectroscopies.

Initial stages of benzotriazole adsorption on the Cu(111) surface.

Benzotriazole (BTAH) has been used as a copper corrosion inhibitor since the 1950s; however, the molecular level detail of how inhibition occurs remains a matter of debate. The onset of BTAH adsorption on a Cu(111) single crystal was investigated via scanning tunnelling microscopy (STM), vibrational spectroscopy (RAIRS) and supporting DFT modelling. BTAH adsorbs as anionic (BTA(-)), CuBTA is a minority species, while Cu(BTA)2, the majority of the adsorbed species, form chains, whose sections appear to diffuse in a concerted manner.

X-ray photoelectron and infrared spectroscopies of quartz samples of contrasting toxicity.

An exploratory XPS and FTIR investigation of the surfaces of bulk quartz powders widely used in toxicological studies (DQ12 and Min-U-Sil 5) was carried with the aim of correlating surface features with toxicity as reflected by indicators of biological response. Some patches of amorphous silica were identified as well as varying amounts of calcium but none of these features correlated with biological response. No evidence of widely-quoted surface silanol (SiOH) structures was found in this investigation and the possibility that FTIR artefacts have been previously misidentified as silanol structures is discussed.