Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Move to the red!

13.09.2010
Design and synthesis of rigid fluorophores

Stable dyes with sharp absorption and fluorescence emission bands in the red or NIR region of the spectrum, combined with high molar absorption coefficients and high fluorescence quantum yields, may find extensive use in many different fields, such as optical engineering, analytical chemistry, biological in vivo imaging and sensing applications, and materials science. In Chemistry—An Asian Journal, Wim Dehaen and co-workers, based at Katholieke Universiteit Leuven (Belgium), Lanzhou University (China), and the Université de Mons (Belgium) describe the preparation of difluoroboron dipyrromethene (BODIPY)-based dyes with increasing conformational rigidity that have absorption in the visible region of the spectrum.


Although a substantial number of BODIPY dye analogues have been developed, primarily through extended conjugation using aryl substituents, the substituted BODIPY dyes show red shifts of over 100 nm but have only low to moderate fluorescence quantum yields owing to non-radiative decay arising from the non-rigid nature of compounds. Alkenyl, and more-recently alkynyl substituents afforded large red shifts, but the rigidity of the triple bond generally results in higher quantum yields. Functionalization of the aromatic rings attached to the BODIPY core with heterocyclic rings even led to near infrared (NIR) emission; however, these dyes require lengthy multi-step syntheses of the fused-ring pyrrole starting materials and are restricted in scope to symmetrical frameworks.

Two BODIPY dyes were synthesized from a conformationally unconstrained indacene using simple palladium catalysis. These dyes showed restricted rotation of their phenoxy moieties, and thus absorb and fluoresce more intensely at longer wavelengths relative to their unrestricted analogues. Furthermore, reduction of the conformational flexibility in these dyes led to significantly higher fluorescence quantum yields. Quantum chemical calculations were also performed which showed that the increase in conformational constraint led to larger spectroscopic shifts. X-ray diffraction analysis showed a progressive increase in the extended planarity of the chromophore in line with increasing conformational rigidity, which explained the larger red shifts in the absorption and emission spectra.

This practically simple design strategy provides promise for the rapid development of new BODIPY-based dyes with increasing structural rigidity. Furthermore, the development of novel dyes with extended planarity is expected to afford higher quantum yields and more-substantial bathochromic shifts into the NIR region, which may find interesting application in a wide variety of fields.

Author: Wim Dehaen, Katholieke Universiteit Leuven (Belgium), http://chem.kuleuven.be/organ/losa/index.htm

Title: Synthesis, Spectroscopy, Crystal Structure Determination, and Quantum Chemical Calculations of BODIPY Dyes with Increasing Conformational Restriction and Concomitant Red-Shifted Visible Absorption and Fluorescence Spectra

Chemistry - An Asian Journal 2010, 5, No. 9, 2016–2026, Permalink to the article: http://dx.doi.org/10.1002/asia.201000248

Wim Dehaen | Chemistry - An Asian Journal
Further information:
http://www.chemasianj.org
http://chem.kuleuven.be/organ/losa/index.htm

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>