Archive for the ‘Uncategorized’ Category

Hydrogen adopts alkali metal position

Hydrogen stands in for a lithium in the cubane core of this alkali metal phenolate

Now, Matthew Davidson and colleagues at the University of Bath in the UK have devised an organometallic synthetic strategy to make pseudocubane motifs of ammonium tris(phenol) ligands and lithium or sodium atoms, where one of the metals has been replaced by a hydrogen atom. The hydrogen forms the rarely reported trifurcated 4-centre hydrogen bond. Such an arrangement is not uncommon for the larger alkali metals, which can accommodate higher coordination numbers, but is not preferred by hydrogen.

Davidson says their interest lies in gaining a better understanding of how ligands like  amine tris(phenolate) can be used to control reactive metal centres. A thorough comprehension of the coordination chemistry and the ability to draw conceptual similarities between the reactivity of hydrogen and metals as Lewis acids could help advance areas such as organocatalysis.


Read the full article in Chemistry World»

Read the original journal article in ChemComm:

Unprecedented participation of a four-coordinate hydrogen atom in the cubane core of lithium and sodium phenolates
David M. Cousins, Matthew G. Davidson and Daniel García-Vivó
Chem. Commun., 2014, Advance Article
DOI: 10.1039/C3CC47393G, Communication

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Potato powered biomotors are cheap as chips

Enzyme rich potato tissue can be used to cheaply and quickly mass produce bubble powered millimotors, new research shows.

Scientists have been developing synthetic self-powered motors over the last ten years after being inspired by the molecular motors that are ubiquitous in nature. These motors, including those responsible for the movement of flagella and cilia, power movement on a micro-scale by utilising fuels present in their surrounding environment.

Synthetic bubble propelled micromotors are traditionally built by coating one half of a tiny pellet with a metal catalyst or enzyme which, when placed in a solution of hydrogen peroxide, catalyses oxygen production to form streams of bubbles. This asymmetric production of bubbles, propels the pellet through the liquid.
 
Potatoes are rich in catalase, an enzyme commonly used in bubble powered micromotors. This led Joseph Wang from the University of California, US, and his colleagues, back to nature to make bubble powered millimotors in a beautifully simple manner. One half of a 2 x 1 mm potato cylinder is capped with epoxy, to mimic the asymmetric design of traditional micromotors. The catalase in the exposed potato tissue catalyses bubble production and propels the potato pellet at speeds of up to 5.12 mm s-1.

C3CC42782J

Read the full article in Chemistry World»

Read the original journal article in ChemComm:
Self-propelled chemically-powered plant-tissue biomotors
Yonge Gu, Sirilak Sattayasamitsathit, Kevin Kaufmann, Rafael Vazquez-Duhalt, Wei Gao, Chunming Wang and Joseph Wang  
Chem. Commun., 2013, 49, 7307-7309
DOI: 10.1039/C3CC42782J

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)