Molecule Within a Molecule
May 12, 2006All children are fascinated by Russian dolls: when the largest outer wooden figure is opened, a second, smaller, nearly identical doll appears. This one can also be opened and so on…. This toy could well have inspired T. Shinmyozu, H. Takemura, M. Yasutake, and K. Sato in Japan to synthesize their cyclophane within a cyclophane.
Cyclophanes are nonplanar polycyclic aromatic compounds, benzene rings in which two opposite carbon atoms are linked by a handle-like bridge. The simplest example would be a benzene ring “basket” with an alkane “handle”. Of course, this cannot be used to make tubes, so the Japanese scientists synthesized larger rings made of several building blocks whose opening is large enough to enclose larger molecules.
They thus allowed pyromellitic dianhydride (benzene-1,2,4,5-tetracarboxylic acid dianhydride) to react with 1,4-bis(aminomethyl)-2,5-dimethoxybenzene. The acid anhydrides combine with the amino groups to form acid imides, which results in rigid rings made of six building blocks with alternating acid imide and dimethoxybenzene units.
X-ray structure analyses show that these rings are not perfectly round but are shaped more like a triangle. At its widest point, the diameter of the ring is 1.2 to 1.3 nm. That is large enough to take up two molecules of the solvent p-xylene. In doing this, two of the cyclophane rings stack on top of each other to form longer smooth tubes. If the solvent for the crystallization was switched to toluene instead of p-xylene, the rings could enclose three solvent molecules. However, in this case the tubes were no longer smooth but had a zig-zag structure instead.
The researchers were interested in trying to incorporate larger molecules, such as a smaller cyclophane made of three benzene rings each bound to the others by a C2H4 bridge. This little cyclophane also has a triangular structure and is able to lodge in the larger cyclophane like a “doll within a doll”. These structures also organized themselves into longer, smooth tubes.
Citation: Teruo Shinmyozu, Cyclophanes Within Cyclophanes: The Synthesis of a Pyromellitic Diimide-Based Macrocycle as a Structural Unit in a Molecular Tube and Its Inclusion Phenomena, Angewandte Chemie International Edition 2006, 45, No. 22, 3643–3647, doi: 10.1002/anie.200504499
Source: Angewandte Chemie
-
Coral growth in Western Australia found to be thriving in warmer water
Feb 03, 2012 |
4 / 5 (3) |
8
-
Space Image: Welcome disruption
Jan 16, 2012 |
5 / 5 (2) |
0
-
A scarcity of women leads men to spend more, save less
Jan 12, 2012 |
4.1 / 5 (10) |
6
-
Book on Richard Feynman nets honors for Arizona State professor
Dec 21, 2011 |
not rated yet |
1
-
Complex sex life of goats could have implications for wildlife management
Dec 14, 2011 |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (31) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (3) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (1) |
0
-
Stem cell question.
Feb 10, 2012
-
Protease cleavage
Feb 10, 2012
-
Pertubance in a model
Feb 10, 2012
-
Cancer drugs and Alzheimer's, Oh my!
Feb 09, 2012
-
Squishing cells
Feb 09, 2012
-
Any books/articles for evolutionary stable strategy models in humans?
Feb 09, 2012
- More from Physics Forums - Biology
More news stories
New kind of solar cell could capture significantly more energy than current cells
New solar cells could increase the maximum efficiency of solar panels by over 25%, according to scientists from the University of Cambridge.
Feb 08, 2012 |
4.5 / 5 (12) |
14
|
Nanoshell whispering galleries improve thin solar panels
Visitors to Statuary Hall in the U.S. Capitol Building may have experienced a curious acoustic feature that allows a person to whisper softly at one side of the cavernous, half-domed room and for another on ...
Nanotechnology / Nanomaterials
Feb 07, 2012 |
4.3 / 5 (6) |
6
|
'Dark plasmons' transmit energy
Microscopic channels of gold nanoparticles have the ability to transmit electromagnetic energy that starts as light and propagates via "dark plasmons," according to researchers at Rice University.
Feb 09, 2012 |
4.8 / 5 (9) |
1
|
Revealing how a battery material works
Since its discovery 15 years ago, lithium iron phosphate (LiFePO4) has become one of the most promising materials for rechargeable batteries because of its stability, durability, safety and ability to deliver ...
Nanotechnology / Nanomaterials
Feb 08, 2012 |
5 / 5 (5) |
0
|
Nanotube therapy takes aim at breast cancer stem cells
Wake Forest Baptist Medical Center researchers have again proven that injecting multiwalled carbon nanotubes (MWCNTs) into tumors and heating them with a quick, 30-second laser treatment can kill them.
Nanotechnology / Bio & Medicine
Feb 09, 2012 |
5 / 5 (1) |
0
|
Walney offshore wind farm is world's biggest (for now)
(PhysOrg.com) -- The Walney wind farm on the Irish Sea--characterized by high tides, waves and windy weather--officially opened this week. The farm is treated in the press as a very big deal as the Walney ...
GPS court ruling leaves US phone tracking unclear
A US Supreme Court decision requiring a warrant to place a GPS device on the car of a criminal suspect leaves unresolved the bigger issue of police tracking using mobile phones, legal experts say.
Europeans protest controversial Internet pact
Tens of thousands of people marched in protests in more than a dozen European cities Saturday against a controversial anti-online piracy pact that critics say could curtail Internet freedom.
Europe stakes billion-dollar bet on new rocket
A pencil-slim rocket is scheduled to lift into space from South America on Monday, carrying a billion-dollar bet that Europe can grab a juicy slice of the market to place satellites in low orbit.
Study finds that anti-diabetic medication can prevent the long-term effects of maternal obesity
In a study to be presented today at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting, in Dallas, Texas, researchers will report findings that show that short therapy with the anti-diabetic medication ...
Netflix settlement trims 14 pct off 4Q earnings
(AP) -- Netflix pressed the rewind button on its fourth-quarter earnings after settling allegations that the video subscription service violated a consumer-privacy law.