A team of Brock University researchers has taken a major step in making chemical reactions cheaper and greener.
Traditionally, the process of catalysis – increasing the rate of a chemical reaction of two or more reactants by adding an additional substance called a catalyst – has relied upon the use of transition metals to be that catalyst.
Transition metals – which are elements, or pure chemical substances consisting of a single type of atom distinguished by its atomic number – have high melting and boiling points, are malleable and conduct electricity and heat.
Examples of transition metals include copper, nickel, rhodium, palladium, platinum, and gold.
But these metals can be precious, expensive, rare and toxic.
A lot of success of transition metal catalysis is due to the fact that they form chemical compounds, called complexes, in which metal has low oxidation state, i.e. retains its electron density.
Enter Brock chemists Georgii Nikonov, Travis Dudding, Art van der Est and graduate students Terry Chu and Lee Belding.
The team has successfully prepared and characterized a complex of non-transition (also called main group) element germanium in the zero oxidation state, so that it resembles a transition metal.
“We want to mimic transition metal chemistry in catalysis, but we want to use better elements,” says Nikonov. “As a first step forward, this result of this complex is inspiring.”
“It’s very recently that people have started to be able to isolate and characterize these compounds,” adds Chu. “We are the first few people to explore this. We’ll open up the field.”
The researchers say germanium is cheaper and emits less toxic by-products than some of the transitional metals.
“This complex could lead to the development of more environmentally friendly catalytic procedures and new electronic devices,” says Dudding. “It opens up a Pandora’s Box of new applications in chemistry for people worldwide.”
The research team’s discovery is one of the first examples of “coordination chemistry” of a main group element, which is the science concerned with the interactions of organic and inorganic ligands with metal centres.
A ligand is an ion or molecule that binds to a central metal atom to form a coordination complex.
The group, which is the first to come up with the coordination compound of germanium, has published its findings in the journal Angewandte Chemie.