Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Researchers 'detune' a molecule: Rice University experiment shows how to soften atomic bonds in a buckyball

Rice University scientists discovered the bonds in a carbon-60 molecule – a buckyball – can be "detuned" when exposed to an electric current in an optical antenna. Credit: Natelson Group/Rice University
Rice University scientists discovered the bonds in a carbon-60 molecule – a buckyball – can be "detuned" when exposed to an electric current in an optical antenna.

Credit: Natelson Group/Rice University

Abstract:
Rice University scientists have found they can control the bonds between atoms in a molecule.

Researchers 'detune' a molecule: Rice University experiment shows how to soften atomic bonds in a buckyball

Houston, TX | Posted on January 16th, 2014

The molecule in question is carbon-60, also known as the buckminsterfullerene and the buckyball, discovered at Rice in 1985. The scientists led by Rice physicists Yajing Li and Douglas Natelson found that it's possible to soften the bonds between atoms by applying a voltage and running an electric current through a single buckyball.

The researchers detailed their discovery this week in the online Proceedings of the National Academy of Sciences.

"This doesn't mean we're going to be able to arbitrarily dial around the strength of materials or anything like that," Natelson said. "This is a very specific case, and even here it was something of a surprise to see this going on.

"But in general, if we can manipulate the charge distribution on molecules, we can affect their vibrations. We can start thinking, in the future, about controlling things in a better way."

The effect appears when a buckyball attaches to a gold surface in the optical nano antenna used to measure the effects of an electric current on intermolecular bonds through a technique called Raman spectroscopy.

Natelson's group built the nano antenna a few years ago to trap small numbers of molecules in a nanoscale gap between gold electrodes. Once the molecules are in place, the researchers can chill them, heat them, blast them with energy from a laser or electric current and measure the effect through spectroscopy, which gathers information from the frequencies of light emitted by the object of interest.

With continuing refinement, the researchers found they could analyze molecular vibrations and the bonds between the atoms in the molecule. That ability led to this experiment, Natelson said.

Natelson compared the characteristic vibrational frequencies exhibited by the bonds to the way a guitar string vibrates at a specific frequency based on how tightly it's wound. Loosen the string and the vibration diminishes and the tone drops.

The nano antenna is able to detect the "tone" of detuned vibrations between atoms through surface-enhanced Raman spectroscopy (SERS), a technique that improves the readings from molecules when they're attached to a metal surface. Isolating a buckyball in the gap between the gold electrodes lets the researchers track vibrations through the optical response seen via SERS.

When a buckyball attaches to a gold surface, its internal bonds undergo a subtle shift as electrons at the junction rearrange themselves to find their lowest energetic states. The Rice experiment found the vibrations in all the bonds dropped ever so slightly in frequency to compensate.

"Think of these molecules as balls and springs," Natelson said. "The atoms are the balls and the bonds that hold them together are the springs. If I have a collection of balls and springs and I smack it, it would show certain vibrational modes.

"When we push current through the molecule, we see these vibrations turn on and start to shake," Natelson said. "But we found, surprisingly, that the vibrations in buckyballs get softer, and by a significant amount. It's as if the springs get floppier at high voltages in this particular system." The effect is reversible; turn off the juice and the buckyball goes back to normal, he said.

The researchers used a combination of experimentation and sophisticated theoretical calculations to disprove an early suspicion that the well-known vibrational Stark effect was responsible for the shift. The Stark effect is seen when molecules' spectral responses shift under the influence of an electric field. The Molecular Foundry, a Department of Energy User Facility at Lawrence Berkeley National Laboratory, collaborated on the calculations component.

Natelson's group had spied similar effects on oligophenylene vinylene molecules used in previous experiments, also prompting the buckyball experiments. "A few years ago we saw hints of vibrational energies moving around, but nothing this clean or this systematic. It does seem like C-60 is kind of special in terms of where it sits energetically," he said.

The discovery of buckyballs, which earned a Nobel Prize for two Rice professors, kick-started the nanotechnology revolution. "They've been studied very well and they're very chemically stable," Natelson said of the soccer-ball-shaped molecules. "We know how to put them on surfaces, what you can do to them and have them still be intact. This is all well understood." He noted other researchers are looking at similar effects through the molecular manipulation of graphene, the single-atomic-layer form of carbon.

"I don't want to make some grand claim that we've got a general method for tuning the molecular bonding in everything," Natelson said. "But if you want chemistry to happen in one spot, maybe you want to make that bond really weak, or at least make it weaker than it was.

"There's a long-sought goal by some in the chemistry community to gain precise control over where and when bonds break. They would like to specifically drive certain bonds, make sure certain bonds get excited, make sure certain ones break. We're offering ways to think about doing that."

Rice graduate student Yajing Li is lead author of the paper. Co-authors are Peter Doak of the Lawrence Berkeley Laboratory; Leeor Kronik, a professor in the Department of Materials and Interfaces, Weizmann Institute of Science, Rehovoth, Israel; and Molecular Foundry director Jeffrey Neaton, a professor of physics at the University of California, Berkeley, and a member of the Kavli Energy NanoSciences Institute at Berkeley. Natelson is a professor of physics and astronomy and of electrical and computer engineering at Rice.

The Robert A. Welch Foundation, the Department of Energy, the Israel Science Foundation and the Lise Meitner Center for Computational Chemistry supported the work. Computations were performed at the National Energy Research Scientific Computing Center.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,708 undergraduates and 2,374 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to tinyurl.com/AboutRiceU.

For more information, please click here

Contacts:
David Ruth
713-348-6327


Mike Williams
713-348-6728

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the abstract at:

Natelson Group:

Related News Press

News and information

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Physics

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024

Scientists use heat to create transformations between skyrmions and antiskyrmions January 12th, 2024

Focused ion beam technology: A single tool for a wide range of applications January 12th, 2024

Imaging

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Laboratories

A battery’s hopping ions remember where they’ve been: Seen in atomic detail, the seemingly smooth flow of ions through a battery’s electrolyte is surprisingly complicated February 16th, 2024

NRL discovers two-dimensional waveguides February 16th, 2024

Govt.-Legislation/Regulation/Funding/Policy

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024

Nanotubes/Buckyballs/Fullerenes/Nanorods/Nanostrings

Catalytic combo converts CO2 to solid carbon nanofibers: Tandem electrocatalytic-thermocatalytic conversion could help offset emissions of potent greenhouse gas by locking carbon away in a useful material January 12th, 2024

TU Delft researchers discover new ultra strong material for microchip sensors: A material that doesn't just rival the strength of diamonds and graphene, but boasts a yield strength 10 times greater than Kevlar, renowned for its use in bulletproof vests November 3rd, 2023

Tests find no free-standing nanotubes released from tire tread wear September 8th, 2023

Detection of bacteria and viruses with fluorescent nanotubes July 21st, 2023

Discoveries

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Tools

First direct imaging of small noble gas clusters at room temperature: Novel opportunities in quantum technology and condensed matter physics opened by noble gas atoms confined between graphene layers January 12th, 2024

New laser setup probes metamaterial structures with ultrafast pulses: The technique could speed up the development of acoustic lenses, impact-resistant films, and other futuristic materials November 17th, 2023

Ferroelectrically modulate the Fermi level of graphene oxide to enhance SERS response November 3rd, 2023

The USTC realizes In situ electron paramagnetic resonance spectroscopy using single nanodiamond sensors November 3rd, 2023

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project