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 Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>