Navigation Links
Chemists demonstrate 'bricks-and-mortar' assembly of new molecular structures

BLOOMINGTON, Ind. -- Chemists at Indiana University Bloomington have described the self-assembly of large, symmetrical molecules in bricks-and-mortar fashion, a development with potential value for the field of organic electronic devices such as field-effect transistors and photovoltaic cells.

Their paper, "Anion-Induced Dimerization of 5-fold Symmetric Cyanostars in 3D Crystalline Solids and 2D Self-Assembled Crystals," has been published online by Chemical Communications, a journal of the Royal Society of Chemistry. It is the first collaboration by Amar Flood, the James F. Jackson Associate Professor of Chemistry, and Steven L. Tait, assistant professor of chemistry. Both are in the materials chemistry program in the IU Bloomington Department of Chemistry, part of the College of Arts and Sciences.

The article will appear as the cover article of an upcoming issue of the journal. The cover illustration was created by Albert William, a lecturer in the media arts and science program of the School of Informatics and Computing at Indiana University-Purdue University Indianapolis. William specializes in using advanced graphics and animation to convey complex scientific concepts.

Lead author of the paper is Brandon Hirsch, who earned the cover by winning a poster contest at the fall 2013 meeting of the International Symposium on Macrocyclic and Supramolecular Chemistry. Co-authors, along with Flood and Tait, include doctoral students Semin Lee, Bo Qiao and Kevin P. McDonald and research scientist Chun-Hsing Chen.

The researchers demonstrate the self-assembly and packing of a five-sided, symmetrical molecule, called cyanostar, that was developed by Flood's IU research team. While researchers have created many such large, cyclic molecules, or macrocycles, cyanostar is unusual in that it can be readily synthesized in a "one pot" process. It also has an unprecedented ability to bind with large, negatively charged anions such as perchlorate.

"This great piece of work, with state-of-the-art studies of the assembly of some beautiful compounds pioneered by the group in Indiana, shows how anions can help organize molecules that could have very interesting properties," said David Amabilino, nanomaterials group leader at the Institute of Materials Science of Barcelona. "Symmetry is all important when molecules pack together, and here the supramolecular aspects of these compounds with a very particular shape present tantalizing possibilities. This research is conceptually extremely novel and really interdisciplinary: It has really unveiled how anions could help pull molecules together to behave in completely new ways."

The paper describes how cyanostar molecules bind with anions in 2-to-1 sandwich-like complexes, with anions sandwiched between two saucer-shaped cyanostars. The study shows the packing of the molecules in repeating patterns reminiscent of the two-dimensional packing of pentagons shown by artist Albrecht Durer in 1525. It further shows the packing to take place not only at but away from the surface of materials.

The future of organic electronics will rely upon packing molecules onto electrode surfaces, yet it has been challenging to get packing of the molecules away from the surface, Tait and Flood said. With this paper, they present a collaborative effort, combining their backgrounds in traditionally distinct fields of chemistry, as a new foray to achieve this goal using a bricks-and-mortar approach.

The paper relies on two complementary technologies that provide high-resolution images of molecules:

  • X-ray crystallography, which is being celebrated worldwide for its invention 100 years ago, can provide images of molecules from analysis of the three-dimensional crystalline solids.
  • Scanning tunneling microscopy, or STM, developed in 1981, shows two-dimensional packing of molecules immobilized on a surface.

The results are distinct, with submolecular views of the star-shaped molecules that are a few nanometers in diameter. (A human hair is about 100,000 nanometers thick).


Contact: Steve Hinnefeld
Indiana University

Related biology technology :

1. Chemists become molecular sculptors, synthesizing tiny, molecular traps
2. University of Utah chemists use nanopores to detect DNA damage
3. Chemists develop innovative nano-sensors for multiple proteins
4. Oregon chemists eye improved thin films with metal substitution
5. NKTR-102 Demonstrates Synergistic Anti-Tumor Activity in Combination with Pegylated Liposomal Doxorubicin in Platinum-Resistant Ovarian Cancer
6. S*BIOs Novel JAK2 Inhibitor Pacritinib (SB1518) and Histone Deacetylase Inhibitor Pracinostat (SB939) Demonstrate Promising Activity in Phase 2 Studies for Patients with Myelofibrosis (MF)
7. AtheroNova Inc. Preclinical Study Demonstrates 95% Reduction in Arterial Plaque Formation
8. Post Heart Attack Recovery Not Aided By Stem Cell Injections, But Trial Demonstrates Promise
9. UCLA researchers demonstrate fully printed carbon nanotube transistor circuits for displays
10. Penn and Brown researchers demonstrate earthquake friction effect at the nanoscale
11. Entinostat Demonstrates Activity in Hodgkins Lymphoma
Post Your Comments:
Related Image:
Chemists demonstrate 'bricks-and-mortar' assembly of new molecular structures
(Date:11/24/2015)... --> --> ... by Transparency Market Research, the global non-invasive prenatal testing ... 17.5% during the period between 2014 and 2022. The ... Analysis, Size, Volume, Share, Growth, Trends and Forecast 2014 ... to reach a valuation of US$2.38 bn by 2022. ...
(Date:11/24/2015)... ... November 24, 2015 , ... In harsh industrial ... points for in-line sensors can represent a weak spot where leaking process media ... of retractable sensor housings , which are designed to tolerate extreme process conditions. ...
(Date:11/24/2015)... LOS ANGELES , Nov. 24, 2015 ... a biotechnology company focused on the discovery, development and ... Marban , Ph.D., Chief Executive Officer, is scheduled to ... December 1, 2015 at 10:50 a.m. EST, at The ... York City . . ...
(Date:11/24/2015)... ... , ... Whitehouse Laboratories is pleased to announce that it has completed construction ... dedicated to basic USP 61, USP 62 and USP 51 testing specific to raw ... and micro testing performed by one supplier. Management has formally announced that ...
Breaking Biology Technology:
(Date:11/9/2015)... 09, 2015 ... the "Global Law Enforcement Biometrics Market ... --> ) has announced the ... Biometrics Market 2015-2019" report to their ... ( ) has announced the addition ...
(Date:10/29/2015)...   MedNet Solutions , an innovative SaaS-based eClinical ... research, is pleased to announce that it has been ... one of only three finalists for a 2015 ... Growing" category. The Tekne Awards honor Minnesota ... innovation and leadership. iMedNet™ eClinical ...
(Date:10/29/2015)... Oct. 29, 2015  Connected health pioneer, Joseph ... explosion of technology-enabled health and wellness, and the business ... The Internet of Healthy Things . ... smartphones even existed, Dr. Kvedar, vice president, Connected Health, ... care delivery, moving care from the hospital or doctor,s ...
Breaking Biology News(10 mins):