Among the most ubiquitous structural motifs in nature, helices play an essential role in a wide range of biological processes. The capacity of certain helix structures to respond to external stimuli by changing shape, in particular, offers key insights in the design of functional molecular devices. As of yet, however, few such structures have been identified that respond to electrochemical inputs, one of the most important types of stimuli.
Now a class of helical structures has been found to do this, and more. o-Phenylenes are densely-packed chains of phenylene (C6H4) compounds linked together at their ortho positions by heavily-angled connections. Despite potentially rich conformational behavior, o-phenylenes are difficult to study and have been all but forgotten since their discovery more than 50 years ago.
In a paper in Nature Chemistry, the RIKEN/JST research group demonstrates a method for synthesizing polymeric o-phenylenes on scales never before observed, the largest reaching some 48 phenylene units. Problems of electrochemical instability which plagued earlier studies are solved by introducing a nitrogen group to the end of the o-phenylene chain, enabling first-ever exploration of o-phenylene oxidation-reduction response.
Experiments with the new o-phenylenes revealed intriguing results. In solution, the helices depart from their folded form to undergo rapid inversion between clockwise and anti-clockwise orientations, yet when they crystallize, they converge uniformly to only one orientation, in a rare process called chiral symmetry-breaking. Removal of a single electron, meanwhile, converts helices across the entire solution to a more compact form, slowing the inversion rate by a factor of more than 450.
Through its parallel to permanent and long-lasting memory, this unique form of conformational rigidity alterable by electrical inputs offers a completely new design concept for nanotechnology, opening new avenues for the design of molecular wires and other nano-scale devices.
For more information, please contact:
Scientists enlist engineered protein to battle the MERS virus
22.05.2017 | University of Toronto
Insight into enzyme's 3-D structure could cut biofuel costs
19.05.2017 | DOE/Los Alamos National Laboratory
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...
22.05.2017 | Event News
17.05.2017 | Event News
16.05.2017 | Event News
22.05.2017 | Materials Sciences
22.05.2017 | Life Sciences
22.05.2017 | Physics and Astronomy