Metal catalysts, with their ability to both speed up chemical reactions and influence product structures, have revolutionized manufacturing of essential goods such as petroleum and pharmaceuticals. The constant search for new catalysts that can improve existing methods has spurred chemists to investigate a relatively unknown part of the periodic table—the rare-earth elements.
Rare earths, named for the uncommon minerals in which they were first discovered, possess remarkable chemical properties owing to their internal electronic configuration. Now, Zhaomin Hou from the RIKEN Advanced Science Institute in Wako and colleagues have used an yttrium-based rare-earth cluster to generate a new series of complexes that hold vital structural clues towards improving catalytic reactions.
Hou and co-workers studied one of industry’s most critical reactions: the reduction of carbon monoxide (CO) molecules attached to transition metal catalysts. In this process, a reagent known as a hydride causes CO to gain electrons or hydrogen, producing useful liquid hydrocarbons. Scientists know little about the mechanism of this reaction, however, and industry greatly desires more efficient catalysts.
First, Hou’s team developed a new molecular rare-earth hydride—a large cluster containing several yttrium, hydrogen, and organic groups—to investigate CO reduction. According to Hou, the rare-earth hydride is extremely reactive towards molecules with triple bonds such as CO.
When mixed together, the rare-earth hydride incorporated the metal–CO complex into its own framework, creating structurally well-defined organic–multimetallic molecules with various degrees of CO reduction. The researchers believe that these new hybrid compounds are important intermediates in the transformation of CO into hydrocarbon molecules.
They also found that different metal–CO complexes generated unique structures with the rare-earth hydride. For example, tungsten–CO complexes added to the yttrium cluster as intact units by bonding oxygen atoms to yttrium sites. With a rhodium–CO complex, however, the C–O bond is cleaved after addition; carbon groups joined directly to yttrium while oxygen atoms moved deeper into the cluster framework.
The ability of rare-earth hydrides to capture ‘snapshots’ of catalytic reactions through an extraordinary variety of metal, carbon, and oxygen bonding interactions promises to spark development of better organic synthetic techniques, a prospect that Hou and colleagues are actively investigating.
“These new organic–multimetallic structures provide well-defined examples of the individual first steps in the reduction of coordinated CO,” says Hou. “And, our findings may give clues for the design of new catalysts for selective synthesis of hydrocarbons from CO reduction.”
The corresponding author for this highlight is based at the Organometallic Chemistry Laboratory, RIKEN Advanced Science Institute.
Saeko Okada | Research asia research news
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses