Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Room Temperature Liquid Porphyrins

24.03.2010
Potential Optical Limiters

Porphyrins have received a great deal of attention in the scientific community owing to their useful application in a wide variety of areas, such as the treatment of cancer and systems that mimic photosynthesis.

A common shortcoming observed in using porphyrins arises from their tendency to form stacks and aggregates, as is common for planar aromatic systems, which results in low solubility, high crystallinity, and high melting point.

In the journal Chemistry—An Asian Journal, a team led by Daniel T. Gryko, based at the Polish Academy of Sciences (Warsaw, Poland), describe the design and synthesis of liquid porphyrin-based compounds that, after suitable structural modifications, may be used as optical limiters.

The study focuses on a homologous series of meso-substituted A4-porphyrins bearing aryl groups with long alkoxy chains. The alkyl chain length ranges from 8 to 18 carbon atoms. The synthesis of these compounds involves a high-yielding two-step process using commercially available starting materials. All porphyrins synthesized are found to be highly soluble in organic solvents. Differential scanning calorimetry (DSC) is used to investigate the thermal properties of the series of porphyrins.

"The behavior of the compounds in the DSC thermograms is very sensitive to the alkoxy chain lengths present in the molecule" writes Gryko. A gradual decrease in the temperature for the crystalline-to-isotropic-liquid phase transition is observed as the length of the alkoxy side chains increase. A minimum is observed for the decycloxy compound, with subsequent elongation of the alkyl chain causing an increase in the melting point. 5,10,15,20-Tetrakis[3,4,5-tri(undecyloxy)phenyl]porphyrin and its decyloxy analogue are both observed to be liquids at room temperature and are shown to have melting points of -24°C and -55°C, respectively.

Such compounds are unprecedented, and these results provide significant insight into the possibilities for the design and synthesis of room temperature liquid porphyrins in a very simple and efficient way. It is known that liquid porphyrins maintain the same spectroscopic features as their solid analogues, therefore, this discovery not only opens the way to design porphyrins possessing such substituents in optical limiting devices but also allows its broader use in other applications where liquidity or very high solubility are desirable.

Author: Daniel T. Gryko, Polish Academy of Sciences, Warsaw (Poland), http://www.icho.edu.pl/ENG/groups/10/10.htm

Title: Meso-Substituted Liquid Porphyrins

Chemistry—An Asian Journal 2010, 5, No. 4, Permalink: http://dx.doi.org/10.1002/asia.200900693

Daniel T. Gryko | Angewandte Chemie
Further information:
http://www.icho.edu.pl/ENG/groups/10/10.htm
http://www.chemasianj.org

Further reports about: Academy Liquid melting point room temperature

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

Guardians of the Gate

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>