Researchers: New discovery in nickel catalysis could enhance metal chemistry segment

By @vitthernandez on
nickel ore
A worker poses with a handful of nickel ore at the nickel mining factory of PT Vale Tbk, near Sorowako, Indonesia's Sulawesi island, January 8, 2014. Indonesia's ban on exports of key mineral ores - unless they are processed in the country - risks backfiring as weaker commodity prices mean it is not cost-effective to invest in expensive smelters and refineries. Picture taken January 8, 2014. Reuters/Yusuf Ahmad

The researchers who discovered a novel way to produce carbon-oxygen (C-O) bond through a dual nickel-photoredox catalyst system said their discovery could not only change the nickel catalysis industry but possibly the entire metals chemistry segment as well.

"We assume that [through this breakthrough] it's not just nickel chemistry that you can dramatically change, but other metals as well. That's [a] very exciting position to be in," David MacMillan, the research’s principal investigator and a professor of chemistry at James S. McDonnell, wrote on online journal Nature.

Just recently, MacMillan’s team announced that it has unlocked a new pathway in nickel catalysis to construct C-O bonds by connecting aromatics, a kind of circular molecules, to molecules that contain alcohol.

"It was extraordinary to see the reaction go from zero to 91 percent yield just by adding a photocatalyst and switching on a light,” MacMillan explained.

It is the first in nickel catalysis history that carbon and oxygen have been successfully cross-coupled, as scientists in the past have always failed in the last step. This final stage includes reductive elimination wherein nickel needs to expunge itself to give way to an effectual C-O bond.

In organic chemistry, cross-coupling refers to a reaction that involves the binding of two hydrocarbon fragments through the aid of a metal catalyst. In MacMillan’s study, however, the scientists combined aromatics to alcohol-containing molecules using a dual nickel-photoredox catalyst system. 

By introducing this kind of photocatalyst, MacMillan and his team successfully removed a single electron from the nickel intermediate to enter its obscure oxidation which is capable of forming the elusive bond. Post-research tests proved the success of the study.

Valerie Shurtleff, a graduate student at the MacMillan lab and co-author of the paper, revealed that the absence of light and the newly discovered photocatalyst would make the bond unsuccessful. MacMillan suggested that this discovery would be valuable to various markets, such as pharmaceutical and agrochemical industries.

This could also enhance demand for nickel from these segments.

Currently, the largest consumer of nickel and other base metals are the steel producers that cater to construction companies, automobile manufacturers, and engineering firms. Currently, the largest consumer of nickel in the world is China, which also uses the metal ore for its pig iron, a cheaper substitute for steel. The demand segment, on the other hand, is dominated by giant mining companies from Australia, New Caledonia, Russia and the Philippines.

However, there are also smaller mining firms that are considered “big” and “promising” by experts for their exceptional work on their respective mining projects. The most popular of which is Amur Minerals (London AIM: AMC) , also from Russia, which has a projected ore production of 90 million tons, one of the biggest in the segment today. It is also among the few companies that maintained their stock prices at high levels despite the market’s current state, which is precarious and unpredictable.

Metal catalysis is essential in producing more efficient, environment-friendly, and cheaper products from ore. It also plays an important role in improving and maintaining air, water, and soil quality that are crucial to the production of any product that depends heavily on it such as steel and wires. Over the years, the successes in the catalysis segment have made ore-dependent products more efficient and cheaper.

According to Karl Collins of Chemistry World, one of the reasons why nickel became a favourite for contemporary catalysis among other metals is due to its unique physical characteristics.

“[Nickel] has a particular aptitude in enabling reductive cross-couplings and functional group transformations; and the ability to undergo single-electron transfer and two-electron processes (for example oxidative addition and reductive elimination). Add to that facile oxidative addition and slow b-hydride elimination processes relative to palladium, and it is clear that nickel has great value in its own right,” he wrote.

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