Dalton Transactions Blog

The ability of hydrogenase enzymes to reversibly catalyse the reduction of protons to form molecular hydrogen (H₂) has attracted a great deal of research interest. Synthetic mimics of the hydrogenase active site could potentially replace expensive platinum catalysts in hydrogen fuel cells. Currently these mimics are significantly less efficient than the natural enzyme and they are oxygen sensitive. It is thought that by creating a stable peptide based enviroment around the mimic, the stability and efficiency could be improved.

Encapsulating a hydrogenase mimic into a hydrogel causes a restriction in isomerisation after photolysis

Researchers from the Hunt and Ulijn groups at the University of Strathclyde and  the Pickett group from the University of East Anglia have successfully encapsulated a [FeFe]-hydrogenase active site mimic into a dipeptide based hydrogelator. Their research has shown that there is a stark difference in the behaviour of the active site mimic in the gel phase compared to the solution phase. Experiments show that the mimic is significantly more stable in the gel phase and is less senstive to water and UV light which could potentially help to improve catalytic activity.

To find out more, read the full Daltons Transactions article…

David Emslie and colleagues from McMaster University describe the synthesis of a new rigid NSN-donor ligand as well as the preparation of uranium(IV) and uranium(III) complexes using this ligand and a previously prepared NON-donor ligand. A combination of cyclic voltammetry, DFT calculations and Atoms In Molecules calculations were used to compare U–SAR₂ and U–OAr₂ bonding and the results indicated increased covalency in U-SAR₂ bonds that is probably due to the short U-S distances and tight C-S-U angles in the complexes.  This work will aid the advancement of approaches for lanthanide/actinide separation in nuclear fuel reprocessing as well as analytical actinide detection.

Rigid NON- and NSN-ligand complexes of tetravalent and trivalent uranium.

Download the full paper below which is being published as part of an upcoming Dalton Transactions special issue, New Talent: the Americas…

Rigid NON- and NSN-ligand complexes of tetravalent and trivalent uranium: comparison of U–OAr₂ and U–SAr₂ bonding
Balamurugan Vidjayacoumar,  Sougandi Ilango,  Matthew J. Ray,  Terry Chu,  Kristopher B. Kolpin,  Nicholas R. Andreychuk,  Carlos A. Cruz,  David J. H. Emslie,  Hilary A. Jenkins and James F. Britten
Dalton Trans., 2012
DOI: 10.1039/C2DT30247K

You may also find this 2010 Dalton Transactions themed issue on New horizons in organo-f-block chemistry interesting.

Remember you can keep up to date with all the latest news in inorganic chemistry by following us on twitter and signing up to our e-alert service.

Ira Weinstock and colleagues from Ben Gurion University of the Negev have used cryogenic transmission electron microscopy to evaluate the interactions of polyoxometallates of different dimensions and shapes with gold nanoparticles.  The study revealed  a “face-down” orientation of the Pressyler ion  [NaP₅W₃₀O₁₁₀]^14–, and a “tilted” orientation for the Finke-Droege ion [P₄W₃₀Zn₄(H₂O)₂O₁₁₂]^16–, contributing to important ongoing studies on the design of functional-POM protected metal nanoparticles.

"Face-down" orientation of Pressyler ion maximises interactions between cluster anion and Au surface.

To read more, download the communication now – it’s free to access.

Orientations of polyoxometalate anions on gold nanoparticles
Shelly Sharet,  Ella Sandars,  Yifeng Wang,  Offer Zeiri,  Alevtina Neyman,  Louisa Meshi and Ira A. Weinstock
Dalton Trans., 2012
DOI: 10.1039/C2DT30592E

The findings in the above HOT communication are due to be included in an upcoming themed issue on Polyoxometalates, guest edited by Leroy Cronin and Deliang Long.

Yifeng Wang and Ira Weinstock’s previous Dalton Transactions perspective might also be of interest….

Cation mediated self-assembly of inorganic cluster anion building blocks
Yifeng Wang and Ira A Weinstock
Dalton Trans., 2010, 39, 6143-6152
DOI: 10.1039/C0DT00166J

Are you following us on Twitter? @DaltonTrans

Thomas Gilbert from Northern Illinois University reports on a computational study looking at Ar₃B–ONN–PR₃ complexes that result from reactions between borane-phosphine frustrated Lewis pairs and N₂O.  By exploring the structure, stability, mechanism of formation and functionalisation of Ar₃B–ONN–PR₃ complexes, we can further understand how frustrated Lewis pairs can capture small molecules, like N₂O, and hold them for derivatisation, in a similar way to enzymes.

A key finding from this study is a symbiotic relationship that forms between Lewis acid and Lewis base to overcome endothermic or weakly exothermic energetics, forming one structural isomer in preference to others.  Gilbert makes several other exciting conclusions so download the manuscript whilst it’s free to find out more….

Computational studies of complexation of nitrous oxide by borane–phosphine frustrated Lewis pairs
Thomas M. Gilbert
Dalton Trans., 2012
DOI: 10.1039/C2DT30208J

Frustrated Lewis pairs are compounds or mixtures combining sterically hindered Lewis donors and acceptors.  Such systems are capable of unique reactivity with fascinating applications in stoichiometry and catalysis.  Dalton Transactions will be publishing a themed issue on frustrated Lewis pairs later in the year – below are some other articles due to be included in the issue:

Exchange chemistry of tBu₃P(CO₂)B(C₆F₅)₂Cl
Rebecca C. Neu,  Gabriel Ménard and Douglas W. Stephan
Dalton Trans., 2012
DOI: 10.1039/C2DT30206C

Dimeric aluminum–phosphorus compounds as masked frustrated Lewis pairs for small molecule activation
Steffi Roters,  Christian Appelt,  Hauke Westenberg,  Alexander Hepp,  J. Chris Slootweg,  Koop Lammertsma and Werner Uhl
Dalton Trans., 2012
DOI: 10.1039/C2DT30080J