Chemical Science Blog

The in vivo toxicity of iron nanoparticles in rats has been tested by a group of French and Tunisian scientists, who found that the compounds are not metabolised by the animals and cause no toxic effects.

The group tested three different porous iron(III) metal-organic framework (MOF) nanoparticles, injecting them intravenously and studying their distribution, metabolism and excretion. The nanoparticles are rapidly sequestered by the liver and spleen and, after biodegradation, are directly excreted from the body through urine or faeces without metabolisation, substantial toxicity or affecting organ function.

There is currently much concern and debate over the safety and toxicity of nanoparticles, especially with regard to human health. This study shows that biodegradable non-toxic iron(III) carboxylate MOF nanoparticles could have real potential for future biomedical applications.

Read the ‘HOT’ Chemical Science article in full:

In depth analysis of the in vivo toxicity of nanoparticles of porous iron(III) metal-organic frameworks
Tarek Baati , Leila Njim , Fadoua Neffati , Abdelhamid Kerkeni , Muriel Bouttemi , Ruxandra Gref , Mohamed F Najjar , Abdelfateh Zakhama , Patrick Couvreur , Christian Serre and Patricia Horcajada
Chem. Sci., 2013, DOI: 10.1039/C3SC22116D

Geoff Nelson, our new guest web-writer for Chemical Science, blogs about recent findings on van der Waals interactions in non-polar liquids.  Read his first Chem Sci blog post below:

Professor Christopher Hunter, in his latest Edge article, notes that the thermodynamic properties of the van der Waals interactions between non-polar molecules can be predicted based on their calculated molecular surface areas (0.3 kJ mol^-1 Å^-2).  His findings help simplify computational approaches to the design of molecular binding sites or self-assembled molecules.

Prof Hunter’s article includes a detailed model for the behaviour of the van der Waals interaction at liquid-vapor and liquid-liquid interfaces.  Each molecule has ‘surface contact points’ capable of van der Waals interactions with the external environment.  These contacts can be made and broken, depending on the space around the molecule.  The total number of contacts determines the total van der Waals contribution to free energy.  This model helps explain the physical basis of several thermodynamic events (e.g., melting).

The choice of non-polar liquids as the chemical system to study was ideal to isolate the van der Waals interaction, as other non-covalent interactions are minimised (e.g., electrostatic). 

Potent pharmaceuticals and stable self-assembled structures depend on effective binding between molecules.  Predicting the chemical structure necessary to promote such binding is now made easier by Professor Hunter’s research.

Read this Chemical Science Edge article in full:

van der Waals interactions in non-polar liquids

Christopher A. Hunter

Chem. Sci., 2013,4, 834-848

DOI: 10.1039/C2SC21666C

Geoff Nelson is a new guest web-writer for Chemical Science.  He currently works as a post-doctoral research associate in Dr David Payne’s research group in the Department of Materials at Imperial College, London.  Geoff’s current research concerns the synthesis and characterization of post-transition metal oxides for use in the energy sector.  His other research interests include carbon-based materials, biophysical chemistry, and surface science.

Scientists in the US have reported a new insight into the understanding of the bonding trends within, and the differences between, the 4f and 5f element series with soft donor atom ligands.

The coordination chemistry and differing bond lengths explain the covalency of different 4f and 5f elements, they say. The team studied a series of actinide versus lanthanide complexes.

This work is useful for the design and optimisation of actinide separation schemes (for nuclear fuel).

Read the Chemical Science article for free today:

Uncovering f-Element Bonding Differences and Electronic Structure in a Series of 1:3 and 1:4 Complexes with a Diselenophosphinate Ligand
M B Jones et al, Chem. Sci., 2012, DOI: 10.1039/c2sc21806b