Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Catching a chemical butterfly

22.11.2010
Bulky molecules help trap boron compounds into a never-before-seen structural arrangement

When it comes to chemical bonding, boron has a reputation for being unconventional. While covalent bonds are usually formed by sharing two electrons between two atoms, some compounds—including diboranes (B2H6) —contain B–H–B bonds in which an electron pair is distributed over three sites.

The electron-deficient nature of these ‘3-center, 2-electron’ bonds can generate a variety of distinct chemical structures, some of which—such as triple-bonded diborane derivatives—have only been seen theoretically.

Kohei Tamao and colleagues from the RIKEN Advanced Science Institute in Wako and Kyoto University have now isolated the first stable diborane molecule with butterfly-shaped B–H–B bonds and a boron–boron link with triple bond characteristics1. This discovery unlocks new insights into the workings of 3-center, 2-electron boron interactions and puts scientists one step closer to synthesizing the elusive boron–boron triple bond.

The key to this approach is a bulky molecule known as ‘Eind’ that contains a rigid core of fused hydrocarbon rings covered with ethyl side chains. Previously, the researchers used Eind ligands to stabilize heavy elements into multiply bonded species2. This time, the team hoped to generate a neutral boron–boron double bond by substituting Eind groups for hydrogen atoms in diborane.

However, after characterizing the structure of the diborane–Eind compound—a difficult task requiring synchrotron x-rays to detect hydrogen atom positions—the researchers saw a previously unidentified arrangement at the B2H2 core: a central boron–boron connection nearly as short as a theoretical triple bond, flanked by two symmetric B–H–B ‘wings’ (Fig. 1). “We did not expect this butterfly-shaped structure at first, and finding it was a kind of serendipity,” says co-author Yoshiaki Shoji.

Quantum computations revealed that the Eind ligands enforced a linear bonding geometry upon the boron atoms, creating molecular energy levels closely related to the triple-bond species. Furthermore, the bridging hydrogen atoms enhanced the multiple bonding characteristics. “Based on this analysis, it is possible to consider triple bonding interactions between the two boron atoms,” says team-member Tsukasa Matsuo.

Matsuo notes that the butterfly-shaped molecule already displays unique chemical reactivity, and the insights gained from this new structure could lead to additional multiply-bonded diboranes. “We may be able to synthesize a more triply bonded species in the near future by replacing the bridging hydrogen atoms with alkali metals,” he says. “At the moment, this compound is just a dream but I think we have a chance to obtain it.”

The corresponding author for this highlight is based at the Functional Element-Organic Chemistry Unit, RIKEN Advanced Science Institute

1. Shoji, Y., Matsuo, T., Hashizume, D., Fueno, H., Tanaka, K. & Tamao, K. A stable doubly hydrogen-bridged butterfly-shaped diborane(4) compound. Journal of the American Chemical Society 132, 8258–8260 (2010).

2. Li, B., Matsuo, T., Hashizume, D., Fueno, H., Tanaka, K. & Tamao, K. ð-Conjugated phosphasilenes stabilized by fused-ring bulky groups. Journal of the American Chemical Society 131, 13222–13223 (2009).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>