Subscribe free to our newsletters via your
. 24/7 Space News .




NANO TECH
Making functionalized nanocarbons
by Staff Writers
Nagoya, Japan (SPX) Jan 28, 2015


This image shows a one-pot selective monofunctionalization of CPP via a chromium complex. Image courtesy ITbM, Nagoya University. For a larger version of this image please go here.

A team of chemists at Nagoya University has synthesized novel transition metal-complexed cycloparaphenylenes (CPPs) that enable selective monofunctionalization of CPPs for the first time, opening doors to the construction of unprecedented nanocarbons.

Nagoya, Japan - Professor Kenichiro Itami, Yasutomo Segawa and Natsumi Kubota of the JST-ERATO Itami Molecular Nanocarbon Project and the Institute of Transformative Bio-Molecules (ITbM), Nagoya University have synthesized novel cycloparaphenylene (CPP) chromium complexes and demonstrated their utility in obtaining monofunctionalized CPPs, which could become useful precursors for making carbon nanotubes with unprecedented structures.

CPPs consist of a chain of benzene rings and are the shortest segment of carbon nanotubes. Since their first synthesis and isolation in 2008, CPPs have attracted wide attention in the fields of materials science and supramolecular chemistry.

Applying the basic concepts of chromium arene chemistry, Itami and his coworkers have performed the first selective installation of a functional group on CPP, which has previously been difficult due to multiple reactive arene sites on the CPP ring. By being able to selectively install and tune the functional groups on CPPs, it is envisaged that carbon nanotubes with new properties can be constructed by this method.

The study, published online on January 12, 2015 in the Journal of the American Chemical Society, illustrates the first synthesis, isolation and analysis of a CPP chromium complex, which enables a one-pot access to monofunctionalized CPPs. This outcome is believed to be a significant advance in the fields of both CPP chemistry and organometallic chemistry.

Arenes are known to coordinate to transition metals and the corresponding metal complexes exhibit different reactivities relative to the free arene. CPPs, which consist of a chain of arenes, also reacted with chromium carbonyl to successfully generate the first chromium complex of CPP. Interestingly, the main product was a CPP with one chromium moiety complexed to one arene on the outer side of the ring, as confirmed by 1H NMR (nuclear magnetic resonance) spectroscopy, high-resolution mass spectrometry and X-ray crystallography.

"Chromium arene chemistry is a well-established area and we decided to apply this organometallic method to synthesize the first CPP chromium complex," says Itami, the Director of the JST-ERATO project and the Institute of Transformative Bio-Molecules.

"As CPPs have a number of arene rings, we initially expected that chromium would form a complex with each arene ring," says Segawa, a group leader of the JST-ERATO project. "However, we were surprised to see that CPP reacted with chromium in a 1:1 ratio in all the conditions that we tried. Simulation of the molecular structure suggested that the first equivalent of chromium complexed to CPP lowers its reactivity, thus preventing the reaction with a second chromium moiety."

Upon finding that a monometallic CPP complex could be obtained, Itami's team explored the possibility of obtaining monofunctionalized CPPs from this complex. Itami and Segawa describe the steps in achieving this.

"This was not an easy task as chromium arene complexes are usually air and light sensitive, and CPP chromium complexes were no exception. But Natsumi worked persistently to obtain a pure crystal of the first CPP chromium complex," says Itami. "We then performed the subsequent reactions in one-pot, to synthesize monofunctionalized CPPs after addition of base/electrophiles and removal of the metal from the CPP chromium complex," says Segawa.

Selective monofunctionalizations of CPPs i.e. installation of one functional group at a single position on the arene ring, are difficult to achieve as all carbon-hydrogen bonds on the arene rings are chemically equivalent. Direct functionalization of metal-free CPPs usually leads to multiple substitutions on the arene rings in an uncontrolled manner. Despite CPPs being desirable components for carbon nanotubes, there has been no efficient method to obtain directly functionalized CPPs up to now.

"We were pleased to see that a functional group could be selectively installed on one arene ring via chromium coordination of CPPs," says Segawa. "As electrophiles, we utilized silyl, boryl and ester groups, which act as handles that can be easily transformed to other useful functionalities," he continues. Itami says, "We hope that this new approach evolves to become a valuable method to construct carbon nanotubes with unique structures and properties."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Institute of Transformative Bio-Molecules (ITbM), Nagoya University
Nano Technology News From SpaceMart.com
Computer Chip Architecture, Technology and Manufacture






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





NANO TECH
Nanoshuttle wear and tear: It's the mileage, not the age
New York NY (SPX) Jan 28, 2015
As nanomachine design rapidly advances, researchers are moving from wondering if the nanomachine works to how long it will work. This is an especially important question as there are so many potential applications, for instance, for medical uses, including drug delivery, early diagnosis, disease monitoring, instrumentation, and surgery. In a new study led by Henry Hess, associate professor ... read more


NANO TECH
Service Module of Chinese Probe Enters Lunar Orbit

Service module of China's lunar orbiter enters 127-minute orbit

Chinese spacecraft to return to moon's orbit

Russian Company Proposes to Build Lunar Base

NANO TECH
Gully patterns document Martian climate cycles

The two faces of Mars

Several Drives This Week Put Opportunity Near Marathon Distance

Helicopter Could be 'Scout' for Mars Rovers

NANO TECH
NASA, Boeing, SpaceX Outline Objectives to ISS Flights

Boeing will be first to carry US astronauts to space

Japanese businessman set to resume space tourist training

Sailing spacecraft LightSail to harness power of solar wind

NANO TECH
More Astronauts for China

China launches the FY-2 08 meteorological satellite successfully

China's Long March puts satellite in orbit on 200th launch

Countdown to China's new space programs begins

NANO TECH
NASA's CATS Installed on ISS by Robotic Handoff

Roscosmos, NASA Still Planning on Sending Men Into Space

Russian Cargo Spacecraft to Supply ISS With Black Caviar

Astronauts' year-long mission will test limits

NANO TECH
SpaceX releases animation of heavy-lift Falcon rocket

NASA TV Coverage Reset for Launch of Newest Earth-Observing Mission

Japan delays launch of satellite due to weather

British Satellite to Be Launched by Russian Proton-M Carrier Rocket

NANO TECH
Dawn ahead!

Habitable Evaporated Cores

Smaller Gas Giants Could Support Life

Will NASA's TESS Spacecraft Revolutionize Exoplanet Hunting?

NANO TECH
Vanguard Delivers Advanced EHF Bus Structure Assembly

Graphene edges can be tailor-made

The laser pulse that gets shorter all by itself

Eyeglasses that turn into sunglasses - at your command




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.