Formation of substituted dioxanes in the oxidation of gum arabic with periodate.

Renewable polysaccharide feedstocks are of interest in bio-based food packaging, coatings and hydrogels. Their physical properties often need to be tuned by chemical modification, by oxidation using periodate, to introduce carboxylic acid, ketone or aldehyde functional groups. The reproducibility required for application on an industrial scale, however, is challenged by uncertainty about the composition of product mixtures obtained and of the precise structural changes that the reaction with periodate induces.

Single wavelength colour tuning of spiropyran and dithienylethene based photochromic coatings.

Controlling the transmission of thin films with external stimuli is an important goal in functional optical materials and devices. Tuning is especially challenging where both broad band (neutral density filtering) and spectrally varied (colour) transmission are required. The external control provided by photochemically driven switching, between transmission levels and colours, is functionally simple from a device perspective.

Widening the Window of Spin-Crossover Temperatures in Bis(formazanate)iron(II) Complexes via Steric and Noncovalent Interactions.

Bis(formazanate)iron(II) complexes undergo a thermally induced = 0 to = 2 spin transition in solution. Here we present a study of how steric effects and π-stacking interactions between the triarylformazanate ligands affect the spin-crossover behavior, in addition to electronic substituent effects. Moreover, the effect of increasing the denticity of the formazanate ligands is explored by including additional OMe donors in the ligand ().

Filter paper based SERS substrate for the direct detection of analytes in complex matrices.

Surface-enhanced Raman spectroscopy (SERS) is an emerging analytical technique for chemical analysis, which is favourable due to its combination of short measurement time, high sensitivity and molecular specificity. However, the application of SERS is still limited, largely because in real samples the analyte is often present in a complex matrix that contains micro/macro particles that block the probe laser, as well as molecular contaminants that compete for the enhancing surface. Here, we show a simple and scalable spray-deposition technique to fabricate SERS-active paper substrates which combine sample filtration and enhancement in a single material.