Highway to hydrogenase: A new way to obtain the hydrogenase cofactor azadithiolate

Jan 24, 2011

To obtain hydrogen as an energy-rich and environmentally "clean" fuel by an inexpensive, simple method without using expensive metal catalysts preoccupies scientists around the world. Hydrogenases, enzymes employed by organisms to yield hydrogen under anaerobic conditions, are being studied intensively as alternative systems. A very popular research strategy is to build enzyme models that can then be modified to bring them closer to the ultimate goal of functioning even in the presence of some oxygen and not being impeded, or “poisoned”, by the hydrogen gas produced.

Azadithiolate (S−–CH2–NH–CH2–S−) is one of the seven cofactors that make up an important part of such a hydrogenase catalyst. Thomas Rauchfuss and his team at the University of Illinois at Urbana-Champaign developed a new approach to obtain this cofactor, which is described in the Short Communication published in the European Journal of Inorganic Chemistry.

This new approach employs organotitanium compounds, which are known to enable the synthesis of unusual ligands containing sulfur. A dithiolatotitanocene complex was first synthesized, demonstrating that titanocene stabilizes azadithiolate ligands. The next step was to transfer the azadithiolate ligand from the titanocene to a dinuclear iron center, which was successfully carried out with efficiency and good yield.

The importance of this new route to obtain diiron azadithiolato complexes is that it proceeds with high yield and does not require complicated reagents. In addition to describing the first synthesis and structural characterization of an azadithiolato complex not based on the diiron core, the scientists have succeeded in transferring the azadithiolate ligand to the diiron center, which enables further studies of this important cofactor.

Explore further: New star-shaped molecule breakthrough

More information: Thomas Rauchfuss, A New Route to Azadithiolato Complexes, European Journal of Inorganic Chemistry, dx.doi.org/10.1002/ejic.201001208

add to favorites email to friend print save as pdf

Related Stories

Synthetic catalyst mimics nature's 'hydrogen economy'

May 18, 2009

By creating a model of the active site found in a naturally occurring enzyme, chemists at the University of Illinois have described a catalyst that acts like nature's most pervasive hydrogen processor.

Better chemistry through living models

Jun 06, 2007

Scientists at Pacific Northwest National Laboratory will receive $1.98 million from the U.S. Department of Energy over the next three years to emulate nature’s use of enzymes to convert chemicals to energy, PNNL announced ...

Recommended for you

New star-shaped molecule breakthrough

16 hours ago

(Phys.org) —Scientists at The University of Manchester have generated a new star-shaped molecule made up of interlocking rings, which is the most complex of its kind ever created.

Smartgels are thicker than water

Sep 19, 2014

Transforming substances from liquids into gels plays an important role across many industries, including cosmetics, medicine, and energy. But the transformation process, called gelation, where manufacturers ...

Separation of para and ortho water

Sep 18, 2014

(Phys.org) —Not all water is equal—at least not at the molecular level. There are two versions of the water molecule, para and ortho water, in which the spin states of the hydrogen nuclei are different. ...

User comments : 0