Nav: Home

Chemical synthesis of nanotubes

January 10, 2019

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.

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."
-end-
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.

University of Tokyo

Related Nanotubes Articles:

Exotic nanotubes move in less-mysterious ways
Rice University researchers capture the first video of boron nitride nanotubes in motion to prove their potential for materials and medical applications.
Groovy key to nanotubes in 2D
New research offers a groovy answer to the question of what causes carbon nanotubes to align in ultrathin crystalline films discovered at Rice.
Growing carbon nanotubes with the right twist
Researchers synthetize nanotubes with a specific structure expanding previous theories on carbon nanotube growth.
Clean carbon nanotubes with superb properties
Scientists at Aalto University, Finland, and Nagoya University, Japan, have found a new way to make ultra-clean carbon nanotube transistors with superior semiconducting properties.
Watching energy transport through biomimetic nanotubes
Scientists from the University of Groningen (the Netherlands) and the University of Würzburg (Germany) have investigated a simple biomimetic light-harvesting system using advanced spectroscopy combined with a microfluidic platform.
Neural networks will help manufacture carbon nanotubes
A team of scientists from Skoltech's Laboratory of Nanomaterials proposed a neural-network-based method for monitoring the growth of carbon nanotubes, preparing the ground for a new generation of sophisticated electronic devices.
Photovoltaic nanotubes
Physicists discovered a novel kind of nanotube that generates current in the presence of light.
Chemical synthesis of nanotubes
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.
Nanotubes may give the world better batteries
Rice University scientists use thin films of multiwalled carbon nanotubes to keep lithium metal from sprouting dendrites, tentacle-like growths that can cause batteries to fail.
Deformation of nanotubes to control conductivity
Scientists from the NUST MISIS Laboratory of Inorganic Nanomaterials together with their international colleagues have proved it possible to change the structural and conductive properties of nanotubes by stretching them.
More Nanotubes News and Nanotubes Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.