Metal Template Synthesis of Molecular Knots and Links

The use of metal ions as templates to direct the assembly of complex architectures and topologies is briefly reviewed, highlighting milestones in the field from [2]catenanes, through to trefoil knots, Solomon links, Borromean rings and most recently to a molecular pentafoil knot

Controlled Diffusion of Photoswitchable Receptors by Binding Anti-electrostatic Hydrogen-Bonded Phosphate Oligomers

Dihydrogen phosphate anions are found to spontaneously associate into anti-electrostatic oligomers via hydrogen bonding interactions at millimolar concentrations in DMSO. Diffusion NMR measurements supported formation of these oligomers, which can be bound by photoswitchable anion receptors to form large bridged assemblies of approximately three times the volume of the unbound receptor. Photoisomerization of the oligomer-bound receptor causes a decrease in diffusion coefficient of up to 16%, corresponding to a 70% increase in effective volume. This new approach to external control of diffusion opens prospects in controlling molecular transport using light

Multi-pyridine decorated Fe(ii) and Ru(ii) complexes by Pd(0)-catalysed cross couplings: new building blocks for metallosupramolecular assemblies

Eight metal complexes of the type [M(tpy)2]2+ (tpy = 2,2′:6′,2′′-terpyridine) featuring four pendant pyridine rings are reported and characterised by NMR, MS, absorption spectroscopy and electrochemical methods. Palladium-mediated Suzuki and Sonogashira cross-coupling reactions were performed on both free 4′-(3,5- dibromophenyl)-tpy and its Ru(ii) complex in good yields. The ready N-alkylation of the pendant pyridyl units has significant influence on the absorption and electrochemical reduction of the complexes, processes which are localised on the periphery and leaves the [Ru(tpy)2]2+ core essentially unaffected. The binding of metal ions by the free pyridines is also demonstrated as means of assembling larger ordered non-covalent structures. This journal i

Reversibly tuning the viscosity of peptide-based solutions using visible light

Light can be used to design stimuli–responsive systems. We induce transient changes in the assembly of a low molecular weight gelator solution using a merocyanine photoacid. Through our approach, reversible viscosity changes can be achieved via irradiation, delivering systems where flow can be controlled non-invasively on demand

Hue Parameter Fluorescence Identification of Edible Oils with a Smartphone

Food-fraud can be highly lucrative and high accuracy authentication of various foodstuffs is becoming essential. Olive oil is one of the most investigated food matrices, due to its high price and low production globally, with recent food-fraud examples showing little or no high quality olive oil in the tested oils. Here a simple method using a 405 nm-LED flashlight and a smartphone is developed for edible oil authentication. Identification is fingerprinted by intrinsic fluorescent compounds in the oils, such as chlorophylls and poly-phenols. This study uses the hue parameter of HSV-colorspace to authenticate 24 different edible oils of nine different types and 15 different brands. For extra virgin olive oil all the nine samples are well separated from the other oil samples. The rest of the samples were also well type-distinguished by the hue parameter, which is complemented by hue-histogram analysis. This opens up opportunities for low-cost and high-throughput smartphone field-testing of edible oils on all levels of the production and supply chain

4'-Chloro-2,2':6',2''-terpyridine

In the title compound, C15H10ClN3, the terpyridine unit adopts a trans,trans conformation. Mol­ecules assemble into [pi]-stacked columns along the b axis, with an inter­planar distance of 3.51 Å

Hue Parameter Fluorescence Identification of Edible Oils with a Smartphone

Food-fraud can be highly lucrative and high accuracy authentication of various foodstuffs is becoming essential. Olive oil is one of the most investigated food matrices, due to its high price and low production globally, with recent food-fraud examples showing little or no high quality olive oil in the tested oils. Here a simple method using a 405 nm-LED flashlight and a smartphone is developed for edible oil authentication. Identification is fingerprinted by intrinsic fluorescent compounds in the oils, such as chlorophylls and poly-phenols. This study uses the hue parameter of HSV-colorspace to authenticate 24 different edible oils of nine different types and 15 different brands. For extra virgin olive oil all the nine samples are well separated from the other oil samples. The rest of the samples were also well type-distinguished by the hue parameter, which is complemented by hue-histogram analysis. This opens up opportunities for low-cost and high-throughput smartphone field-testing of edible oils on all levels of the production and supply chain

Time-resolved diffusion NMR measurements for transient processes

A general procedure for measurement of time-resolved diffusion coefficients of molecular species by NMR is described, including the use of methanol for fast temperature-independent gradient calibration

Time‐Resolved Diffusion NMR Measurements for Transient Processes

A general procedure for measurement of time-resolved diffusion coefficients of molecular species by NMR is described, including the use of methanol for fast temperature-independent gradient calibration