Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemical synthesis of nanotubes

11.01.2019

Nanometer-sized tubes made from simple benzene molecules

For the first time, researchers used benzene - a common hydrocarbon - to create a novel kind of molecular nanotube, which could lead to new nanocarbon-based semiconductor applications.


A nanometer-sized pNT cylinder made of 40 benzenes. The cylinder is tens of thousands of times thinner than a human hair.

Credit: (c)2018 Hiroyuki Isobe


In crystals, pNT molecules are aligned in parallel.

Credit. (c)2018 Hiroyuki Isobe

Researchers from the Department of Chemistry have been hard at work in their recently renovated lab in the University of Tokyo's Graduate School of Science.

The pristine environment and smart layout affords them ample opportunities for exciting experiments. Professor Hiroyuki Isobe and colleagues share an appreciation for "beautiful" molecular structures and created something that is not only beautiful but is also a first for chemistry.

Their phenine nanotube (pNT) is beautiful to see for its pleasing symmetry and simplicity, which is a stark contrast to its complex means of coming into being. Chemical synthesis of nanotubes is notoriously difficult and challenging, even more so if you wish to delicately control the structures in question to provide unique properties and functions.

Typical carbon nanotubes are famous for their perfect graphite structures without defects, but they vary widely in length and diameter. Isobe and his team wanted a single type of nanotube, a novel form with controlled defects within its nanometer-sized cylindrical structure allowing for additional molecules to add properties and functions.

The researchers' novel process of synthesis starts with benzene, a hexagonal ring of six carbon atoms. They use reactions to combine six of these benzenes to make a larger hexagonal ring called a cyclo-meta-phenylene (CMP). Platinum atoms are then used which allow four CMPs to form an open-ended cube.

When the platinum is removed, the cube springs into a thick circle and this is furnished with bridging molecules on both ends enabling the tube shape.

It sounds complicated, but amazingly, this complex process successfully bonds the benzenes in the right way over 90 percent of the time. The key also lies in the symmetry of the molecule, which simplifies the process to assemble as many as 40 benzenes.

These benzenes, also called phenines, are used as panels to form the nanometer-sized cylinder. The result is a novel nanotube structure with intentional periodic defects. Theoretical investigations show these defects imbue the nanotube with semiconductor characters.

"A crystal of pNT is also interesting: The pNT molecules are aligned and packed in a lattice rich with pores and voids," Isobe explains. "These nanopores can encapsulate various substances which imbue the pNT crystal with properties useful in electronic applications. One molecule we successfully embedded into pNT was a large carbon molecule called fullerene (C70)."

"A team lead by Kroto/Curl/Smalley discovered fullerenes in 1985. It is said that Sir Harold Kroto fell in love with the beautiful molecule," continues Isobe. "We feel the same way about pNT. We were shocked to see the molecular structure from crystallographic analysis. A perfect cylindrical structure with fourfold symmetry emerges from our chemical synthesis."

"After a few decades since the discovery, this beautiful molecule, fullerene, has found various utilities and applications," adds Isobe. "We hope that the beauty of our molecule is also pointing to unique properties and useful functions waiting to be discovered."

###

Journal article

Zhe Sun, Koki Ikemoto, Toshiya M. Fukunaga, Takashi Koretsune, Ryotaro Arita, Sota Sato and Hiroyuki Isobe. Finite phenine nanotubes with periodic vacancy defects. Science. DOI:10.1126/science.aau5441

Related links

Laboratory of Physical Organic Chemistry - http://www.chem.s.u-tokyo.ac.jp/users/physorg/
Department of Chemistry - http://www.chem.s.u-tokyo.ac.jp/en
Graduate School of Science - https://www.s.u-tokyo.ac.jp/en/
ERATO Isobe Degenerate π-Integration Project - http://www.jst.go.jp/erato/isobe/en/index.html

Research Contact

Professor Hiroyuki Isobe
Department of Chemistry, Graduate School of Science, The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 JAPAN
Tel: +81-3-5841-4777
Email: isobe@chem.s.u-tokyo.ac.jp

Press Contacts

Ms. Kristina Awatsu
Office of Communication, Graduate School of Science, The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 JAPAN
Tel: +81-3-5841-8737
E-mail: kouhou.s@gs.mail.u-tokyo.ac.jp

Mr. Rohan Mehra
Division for Strategic Public Relations, The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654 JAPAN
Tel: +81-3-5841-0876
Email: press-releases.adm@gs.mail.u-tokyo.ac.jp

About the University of Tokyo

The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 2,000 international students. Find out more at https://www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.

Rohan Mehra | EurekAlert!

More articles from Life Sciences:

nachricht Chirality in 'real-time'
11.01.2019 | Ecole Polytechnique Fédérale de Lausanne

nachricht Discovery adapts natural membrane to make hydrogen fuel from water
11.01.2019 | DOE/Argonne National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

Im Focus: Physicists uncover new competing state of matter in superconducting material

A team of experimentalists at the U.S. Department of Energy's Ames Laboratory and theoreticians at University of Alabama Birmingham discovered a remarkably long-lived new state of matter in an iron pnictide superconductor, which reveals a laser-induced formation of collective behaviors that compete with superconductivity.

"Superconductivity is a strange state of matter, in which the pairing of electrons makes them move faster," said Jigang Wang, Ames Laboratory physicist and...

Im Focus: Tumors backfire on chemotherapy

Some patients with breast cancer receive chemotherapy before the tumor is removed with surgery. This approach, called 'neoadjuvant' therapy, helps to reduce the size of the tumor to facilitate breast-conserving surgery, and can even eradicate the tumor, leaving few or no cancerous cells for the surgeon to remove. In those cases, the patients are very likely to remain cancer-free for life after surgery.

But not all tumors shrink under chemotherapy. If the tumor resists neoadjuvant therapy, there can be a higher risk of developing metastatic disease, meaning...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Discovery adapts natural membrane to make hydrogen fuel from water

11.01.2019 | Life Sciences

More stable light comes from intentionally 'squashed' quantum dots

11.01.2019 | Physics and Astronomy

The Algae’s Third Eye

11.01.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>