| NSF Org: |
CHE Division Of Chemistry |
| Recipient: |
|
| Initial Amendment Date: | August 8, 2011 |
| Latest Amendment Date: | April 29, 2013 |
| Award Number: | 1057904 |
| Award Instrument: | Continuing Grant |
| Program Manager: |
George Janini
CHE Division Of Chemistry MPS Directorate for Mathematical and Physical Sciences |
| Start Date: | August 15, 2011 |
| End Date: | July 31, 2015 (Estimated) |
| Total Intended Award Amount: | $458,000.00 |
| Total Awarded Amount to Date: | $458,000.00 |
| Funds Obligated to Date: |
FY 2012 = $150,000.00 FY 2013 = $150,000.00 |
| History of Investigator: |
|
| Recipient Sponsored Research Office: |
110 INNER CAMPUS DR AUSTIN TX US 78712-1139 (512)471-6424 |
| Sponsor Congressional District: |
|
| Primary Place of Performance: |
110 INNER CAMPUS DR AUSTIN TX US 78712-1139 |
| Primary Place of
Performance Congressional District: |
|
| Unique Entity Identifier (UEI): |
|
| Parent UEI: |
|
| NSF Program(s): | Macromolec/Supramolec/Nano |
| Primary Program Source: |
01001213DB NSF RESEARCH & RELATED ACTIVIT 01001314DB NSF RESEARCH & RELATED ACTIVIT |
| Program Reference Code(s): |
|
| Program Element Code(s): |
|
| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.049 |
ABSTRACT
The Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division supports the research group of Professor Jonathan Sessler of the University of Texas at Austin on a project that involves the chemistry of expanded porphyrins and related heterocyclic macrocycles. Particular emphasis will be placed on new, electron deficient macrocycles whose electronics are "reversed" compared to those of most expanded porphyrins. These new systems are expected to display interesting molecular recognition properties and act as building blocks for the construction of higher order supramolecular assemblies. This will permit the construction of self-assembled organometallic frameworks, supramolecular organic frameworks, threaded pseudorotaxanes, and self-assembled electron transfer ensembles, among other possibilities. The new molecular and supramolecular materials prepared in the context of this project are expected to be environmentally responsive and to respond to more than one analyte.
It is likely that new chemical entities with broad utility will emerge from this program and be explored by commercial entities. Work in this area contributes to the development of the nation's technological infrastructure. Work in the synthetic porphyrin analogue area is highly interdisciplinary. It involves aspects of organic synthesis, inorganic chemistry, spectroscopy, materials science, catalysis, and supramolecular chemistry. It provides excellent training for young researchers who are then able to work in a variety of settings, including academe, industry, and government. The collaborations with other research groups contribute to the broader impact of the work and provide educational opportunities for the students involved in the project. Collaborative research experience with overseas collaborators is highly beneficial and is contributing to the development of a stronger, scientifically and culturally literate human resource base in the U.S.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
Note:
When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external
site maintained by the publisher. Some full text articles may not yet be available without a
charge during the embargo (administrative interval).
Some links on this page may take you to non-federal websites. Their policies may differ from
this site.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The broad goals of this project centered around using a class of blood pigment analogues, called expanded porphyrins, to explore how changes in chemical structure modulate easy-to-appreciate electronic features, such as color and stability. In particular, we sought to extend the frontiers of understanding in the area of aromaticity. Aromaticity is one of the most fundamental of all concepts in organic chemistry and involves the principle that cyclic compounds with 4n + 2 pi-electrons, such as benzene, will be particularly stable. The converse is that analogous systems with 4n pi-electrons will be unstable. Using large analogues of porphyrin (the organic pigment in hemoglobin) we were able to create a highly stable 4n pi-electron system and show that it could be converted to the aromatic 4n + 2 aromatic form simply by treating with chloride anion, a key ingredient in table salt that is normally thought to be chemically inert. We were also able to create and characterize an intermediate, semi-aromatic 4n + 1 form, an electronic state that hitherto had proved difficult to access.
We also used expanded porphyrins to carry out electron transfer reactions, where the goal was to create a long-lived photoinduced charge separated state, as seen in photosynthesis.
In addition, we used a slightly different set of large cyclic molecules, termed calixpyrroles, to create molecular constructs capable of capturing buckyballs and stabilizing non-covalent ensembles that bear semblance to polymers but without the need for covalent bonds. Applications of these systems to switching, sensing, and so-called molecular logic device construction were also successfully pursued. This latter work thus contributed to our understanding of how information encoded in molecules can be read out in a useful way.
Last Modified: 10/03/2015
Modified by: Jonathan L Sessler
Please report errors in award information by writing to: awardsearch@nsf.gov.
