An alternative C-P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids.

The synthesis of phosphonate esters is a topic of interest for various fields, including the preparation of phosphonic acids to be employed as organic linkers for the construction of metal phosphonate materials. We report an alternative method that requires no solvent and involves a different order of addition of reactants to perform the transition-metal-catalyzed C-P cross-coupling reaction, often referred to as the Tavs reaction, employing NiCl as a pre-catalyst in the phosphonylation of aryl bromide substrates using triisopropyl phosphite. This new method was employed in the synthesis of three novel aryl diphosphonate esters which were subsequently transformed to phosphonic acids through silylation and hydrolysis.

In Situ X-ray Diffraction Investigation of the Crystallisation of Perfluorinated Ce -Based Metal-Organic Frameworks with UiO-66 and MIL-140 Architectures*.

We report on the results of an in situ synchrotron powder X-ray diffraction study of the crystallisation in aqueous medium of two recently discovered perfluorinated Ce -based metal-organic frameworks (MOFs), analogues of the already well investigated Zr -based UiO-66 and MIL-140A, namely, F4_UiO-66(Ce) and F4_MIL-140A(Ce). The two MOFs were originally obtained in pure form in similar conditions, using ammonium cerium nitrate and tetrafluoroterephthalic acid as reagents, and small variations of the reaction parameters were found to yield mixed phases. Here, we investigate the crystallisation of these compounds, varying parameters such as temperature, amount of the protonation modulator nitric acid and amount of the coordination modulator acetic acid.

A new approach to enhancing the CO capture performance of defective UiO-66 via post-synthetic defect exchange.

Zirconium-based metal-organic frameworks (Zr-MOFs) are a subclass of MOFs known for their remarkable stability, especially in the presence of water. This makes them extremely attractive for practical applications, including CO capture from industrial emission sources; however, the CO adsorption capacity of Zr-MOFs is moderate compared to that of the best performing MOFs reported to date. Functionalization of Zr-MOFs with amino groups has been demonstrated to increase their affinity for CO.

Post-Synthetic Ligand Exchange in Zirconium-Based Metal-Organic Frameworks: Beware of The Defects!

Post-synthetic ligand exchange in the prototypical zirconium-based metal-organic framework (MOF) UiO-66 was investigated by in situ solution H NMR spectroscopy. Samples of UiO-66 having different degrees of defectivity were exchanged using solutions of several terephthalic acid analogues in a range of conditions. Linker exchange only occurred in defect-free UiO-66, whereas monocarboxylates grafted at defect sites were found to be preferentially exchanged with respect to terephthalic acid over the whole range of conditions investigated.

Easily Regenerated Readily Deployable Absorbent for Heavy Metal Removal from Contaminated Water.

Although clean and abundant water is the keystone of thriving communities, increasing demand and volatile climate patterns are depleting rivers and aquifers. Moreover, the quality of such water sources is threatened by noxious contaminants, of which heavy metals represents an area of growing concern. Recently, graphene oxide (GO) has been suggested as an adsorbent; however, a support is desirable to ensure a high surface area and an immobile phase.

Nanostructured fusiform hydroxyapatite particles precipitated from aquaculture wastewater.

The present work represents a new approach for the isolation of uniform nano particulate hydroxyapatite (HAp). The chemical characterization of a calcium phosphate product obtained from industrial trout farm aquaculture wastewater by two different routes, washing either with a basic aqueous medium (wash) or followed by a further washing with ethanol (wash), is explored. Characterization of the isolated materials includes morphology studies (SEM and TEM), structural (XRD, electron diffraction), compositional (EDX) and thermogravimetric analysis (TGA).

Activation Effect of Fullerene C60 on the Carbon Dioxide Absorption Performance of Amine-Rich Polypropylenimine Dendrimers.

Invited for this month's cover are Dr. Enrico Andreoli and Prof. Andrew R.

Activation Effect of Fullerene C60 on the Carbon Dioxide Absorption Performance of Amine-Rich Polypropylenimine Dendrimers.

Converting amine-rich compounds into highly effective carbon dioxide (CO2 ) sorbents requires a better understanding and control of their properties. The reaction of fullerene C60 with polyethyleneimine converts the polymer into a high-performance CO2 sorbent. In this study, experimental evidence is reported for the activation effect of C60 on the amine moieties of the polymer.

Cross-linking amine-rich compounds into high performing selective CO2 absorbents.

Amine-based absorbents play a central role in CO2 sequestration and utilization. Amines react selectively with CO2, but a drawback is the unproductive weight of solvent or support in the absorbent. Efforts have focused on metal organic frameworks (MOFs) reaching extremely high CO2 capacity, but limited selectivity to N2 and CH4, and decreased uptake at higher temperatures.

Preparation and evaluation of polyethyleneimine-single walled carbon nanotube conjugates as vectors for pancreatic cancer treatment.

High quality single-walled carbon nanotubes (SWNTs) were obtained following a new purification procedure, based on using Cl gas at high temperature. Cl-treated SWNTs were fluorinated and modified with branched polyethyleneimine (PEI) to afford covalently functionalised PEI-SWNTs, which were then tested for cytotoxicity both in vitro (HPNE and BxPC3 pancreatic cell lines) and in vivo (BxPC3 xenografts from nude mice) to establish that functionalization with lower molecular weight PEI (600 and 1800 Da) achieved higher cell viability in MTT assay. A shortened version of the nanotubes, PEI(1800)-cut-SWNT (1800 Da branched PEI), was also prepared and tested for cellular internalization in the BxPC3 adenocarcinoma cell line.

Electrodeposition of zinc hydroxysulfate nanosheets and reduction to zinc metal microdendrites on polypyrrole films.

Nanothin sheets made of zinc sulfate hydroxide hydrate, ZnSO4[Zn(OH)2]3 x 5H2O, are easily and quickly prepared using an innovative electrochemical route onto polypyrrole-polystyrene sulfonate (PPy-PSS) films. The sheets are characterized using a range of experimental techniques. The deposits are formed on the film surface with instantaneous nucleation to grow into a network of entangled nanosheets.