Archive of older messages (2013 - 1999)
Mayra C. Stuhldreier receives Otto Diels-Prize for best Ph.D. in Chemistry in 2013
Kiel, 19 December 2013:
Mayra C. Stuhldreier had reason for an early Christmas celebration this year: After finishing her Ph.D. in the summer with Summa Cum Laude, she received the Otto Diels-Prize of the Chemistry Department of Christian-Albrechts-University Kiel for the best Ph.D. in Chemistry 2013. In her Thesis on the "Electronic Deactivation Dynamics of DNA Model Systems and Solvation Dynamics of a Natural Antioxidant by Femtosecond Fluorescence and Absorption Spectroscopy", she reported the first spectrally as well as temporally resolved experimental data on the fate of the elusive exciton and excimer states in DNA dinucleotides after UV photoexcitation. With this work, she shed light on a long-lasting highly controversial problem of Photobiophysical Chemistry!
Photo: F. Renth
The Otto-Diels Prize was presented to Mayra (see photo, second from right) at the traditional Christmas Colloquium of the Kiel Division of the German Chemical Society (GDCh) by Prof. Thisbe K. Lindhorst (third from left). At the same meeting, Matthias Lipfert (AK Sönnichsen) received the prize for the best Master degree, four new Bachelors of Science won two-year GDCh memberships and two poster awards were presented for designs of CAU Chemistry Internationalization Posters. The afternoon's programme was completed by three scientific presentations from the Chemistry Institutes, a thoughtful and memorable intermezzo on the birth of Inventions in Chemistry by Thisbe Lindhorst, and traditional Glühwein, Christmas cookies and soup prepared by JCF Kiel.
32nd International Symposium on Free Radicals
Potsdam, 21 - 26 July 2013
124 scientists from 23 countries gathered for the 32nd International Symposium on Free Radicals from 21 - 26 July 2013 at Seminaris SeeHotel in Potsdam, Germany, less than 5 km from the beautiful parks and palaces of Sanssouci. The Symposium featured 22 Invited Talks, 12 Hot Topic Talks, and 87 Poster Presentations.
The Scientific Programme started on Monday morning with an outstanding talk by Hans Jacob Wörner, ETH Zürich, who received the 2013 Broida Prize. In his presentation entitled "Probing Electronic Structure and Dynamics with High Harmonic Spectroscopy", he highlighted new frontiers in electron dynamics by attosecond spectroscopy which will influence free radical research for years to come.
Stimulating presentations and lively scientific discussions followed throughout the entire week.
Photos: K. Laß, F. Renth
The conference excursion by boat on Wednesday led to Schloss Cecilienhof, the site of the Potsdam Conference in 1945. Preceded by a guided tour through Sanssouci Palace, the banquet on Thursday took place at Restaurant "Historische Mühle". The PCCP poster prizes were received by Volker Lutter for his poster on "High-Resolution Infrared Spectroscopy of Ge2C3" and Nancy Faßheber for her poster on "Glyoxal Photolysis as a Quantitative Source of HNO Studied by Frequency Modulation Spectroscopy".
Prof. Terry A. Miller, Ohio State University and Chair of the International Committee, announced that the 33rd International Symposium on Free Radicals will be held from 02 - 07 August 2015 in Squaw Valley, CA.
24 years after the German reunification, the 2013 Free Radicals Symposium has been the first in former East Germany. Jugded from the enthusiastic comments we received after closing, it was a great success. In the words of two participants, the meeting was a "wonderful combination of scientific engagement, cultural experiences, and friendly interactions", "the science was superb ... and the excursions were very, very nice". Everyone already looks forward to the 2015 Symposium!
Click the following links to visit the FRS2013 homepage, to download the FRS2013_AbstractBook, or to view the FRS2013 Photo Gallery.
Shuangqing Wang wins CSC Scholarship to work on his Ph.D. at CAU
Changchun, P.R. China, and Kiel, Germany, 10 May 2013
Shuangqing Wang has been awarded a prestigious 4-year stipend by the China Scholarship Council (CSC) to work in our group towards a Ph.D. from CAU Kiel. Shuangqing holds a B.Sc. in Chemistry from Northeastern Pedagogical University and an M.Sc. in Chemistry and Physics of Polymers from Northeast Normal University, Changchun, Jilin. His Ph.D. project at Kiel will involve the study of photochromic molecular switches in complex environments, including polymers, amorphous films and glasses, by means of ultrafast spectroscopy. He will be starting in Kiel in September 2013.
Uta Corinna Stange wins BASF Prize for best Master Degree in 2012, Mark Dittner receives B.Sc. Prize
Kiel, 20 December 2012:
Uta C. Stange
Two BASF Prizes for the best Master Degrees in 2012 were awarded at this years Christmas Colloquium of the Kiel Division of the German Chemical Society (GDCh), one of them went to Uta Corinna Stange. In her Thesis project, Uta studied the temperature dependence of the ultrafast electronic deactivation of 7Hadenine. She was the first to measure the existence of an activation energy for the electronic deactivation of 7H-Ade. Apparently, the excited wavepacket can be trapped in a shallow potential energy well en route to the conical intersection with the ground state. Vibrational excitation helps the wavepacket to escape from the well.
Mark Dittner received the prize for his B.Sc. degree. Mark's B.Sc. project on a porphyrin derivative switch is in the context of SFB 677 "Function by Switching".
Congratulations to your degrees and awards!
Opening of the New Physical Chemistry Building
Kiel, 17 October 2012:
The new building to which the Institute of Physical Chemistry is moving in 2012 has been officially opened. The Minister of Education and Science of the State of Schleswig-Holstein, Professor Waltraud 'Wara' Wende passed the symbolic key of the building to CAU President Professor Gerhard Fouquet. The new institute building offers 3200 m2 of user area and features modern, state-of-the art teaching and research laboratories. It finally overcomes the severe safety and fire hazards haunting us in the old building. The new building is located in Max-Eyth-Strasse 1, opposite to the Institute of Inorganic Chemistry and close to the Institute of Organic Chemistry.
Photos: Jürgen Haack (c) CAU Kiel
Click here for the official CAU press release.
32nd International Symposium on Free Radicals, 21 - 26 July 2013
Kiel, 18 July 2012:
The 32nd International Symposium on Free Radicals will take place in Potsdam, Germany, from 21 - 26 July 2013 at Seminaris SeeHotel, less than 5 km from the beautiful parks and palaces of Sanssouci.
Want to know why you should participate? The Scientific Programme will be superb!
There will be 22 Invited Talks, a series of Hot Topic Talks selected from the contributed poster abstracts, and two large Poster Sessions. Students who wish to present a poster and register early will obtain assistance towards their registration fees.
Moreover, Potsdam, just 35 km from the center of Germany's hot and sizzling capital Berlin, is a UNESCO World Heritage Site that features more than 20 parks and palaces, the larges ensemble of palaces north of the Alps. And it does not need to be mentioned that Berlin, which has become one of the top tourist destinations in Europe, offers countless landmarks and cultural highlights.
To learn more about the Scientific Programme and the opportunities around the Symposium, visit the Free Radicals 2013 website, and subscribe to the Free Radicals 2013 Newsletter for receiving up-to-date information!
Disperse Red 1 featured on cover of Photochemical & Photobiological Sciences
26 June 2012:
In a femtosecond time-resolved fluorescence up-conversion and broadband transient absorption study carried out in project A1 of the Kiel Collaborative Research Centre 677 "Function by Switching" (SFB 677), we showed that the ultrafast photoisomerization of the push-pull azobenzene photoswitch Disperse Red 1 proceeds via a two-step, sequential mechanism:
J. Bahrenburg, K. Röttger, R. Siewertsen, F. Renth, F. Temps, Photochem. Photobiol. Sci. 11, 1210 - 1219 (2012). DOI: 10.1039/C2PP05400K.
The paper was selected by the editors for the cover of the July 2012 issue.
Click here to download and read the paper.
Click PPS Cover July 2012 to see a large version of the cover page.
Kiel Cluster of Excellence Future Ocean gets funding for phase II
Kiel, 15 June 2012:
Champagne bottles were opened after the announcement by the German Research Foundation (DFG) on June 15 to fund the Excellence Cluster "Future Ocean" for a second five-year period. The DFG also announced continued funding for the Excellence Cluster "Inflammation at Interfaces" and the Graduate School "Human Development in Landscapes". The application for the Cluster "Materials for Life" did not win, but Nano and Surface Sciences with heavy involvement of the Chemistry and Physics Departments will remain the fourth research focus of CAU.
How do micro-scale processes at ocean interfaces affect fluxes of climate-relevant substances? This is the key question of the new Research Area R7: Ocean Interfaces of Future Ocean, where Physical Chemistry is of central importance. The research combines state-of-the-art molecular, microbiological and biogeochemical analytical techniques, laser spectroscopy, micro- and mesocosm experimentation, in-situ measurements and theoretical modeling. Three research foci have been identified:
Focus 1 investigates formation, retention and emission processes of climate-relevant substances.
Focus 2 links biological imprints on extracellular organic matter to interface properties by investigating the accumulation of organic substances and their intense microbial transformation in the surface ocean boundary layer.
Focus 3 investigates (i) chemical aspects of the ocean as a major source and sink for radiatively and chemically active atmospheric trace gases and (ii) the specific roles of the prevalent organic microlayer in sea-air gas exchange processes and as a biochemical reactor.
Link to CAU press release.
Link to Future Ocean homepage.
Link to research area R7: Ocean Interfaces for more information on our research goals.
Spring Meeting of the German Physical Society 2012 in Stuttgart
Stuttgart, 12 - 16 March 2012:
Ph.D. students Thomas Michalak, Mayra Stuhldreier and Katharina Röttger presented their recent results in three talks at the 2012 Spring Meeting of the German Physical Society.
Read their abstracts:
Photodissoziation von fluorierten Acetonen nach Anregung in den S1-Zustand
Ultrafast solvation dynamics of ferulic acid at a micellar surface
Ultrafast Electronic Deactivation Dynamics of the Rare Natural Nucleobases Xanthine and Hypoxanthine
See also Christian Greve's abstract (Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin) on 2D fs IR spectra of Adenosine-Thyidine base pairs:
Ultrafast dynamics of NH stretch vibrations in adenosine-thymidine base pairs in chloroform solution
Link to the complete programme: DPG-Verhandlungen
Gernot Friedrichs promoted to W2 Professor with tenure
Kiel, 22 December 2011:
Following his sucessful work in the last five years in the DFG-funded Cluster of Excellence "The Future Ocean", Gernot Friedrichs has been promoted to W2 Professor of Physical Chemistry and Director of the Institute of Physical Chemistry at CAU Kiel.
After earning his Ph.D. at the University of Göttingen and postdoctoral work at Stanford University, Gernot joined our work group as Research Scientist in January 2002. In August 2007, he officially started his own research group as a Junior Professor in the Excellence Cluster "The Future Ocean". The promotion to W2 Professor with tenure acknowledges his outstanding achievements in the Chemistry of Ocean Interfaces, Ultrahigh Sensitivity Laser Spectroscopy, and High Temperature Chemical Kinetics.
Click here to visit the new Homepage of the Friedrichs Group.
SFB 677 "Function by Switching" extended for second funding period
Kiel, 25 May 2011:
The German Research Foundation (DFG) will fund the Collaborative Research Centre (Sonderforschungsbereich) 677 "Function by Switching" at CAU Kiel with about 8 million EUR for a second period until 2015. In one continuing (A1) and one new project (B10) in our group, we will investigate the dynamics of molecular switches in solution, in self-assembled monolayers on nanoparticles and on flat surfaces, and in functional photoresponsive environments and systems. To achieve our highly challenging goals, we use state-of-the-art femto- and picosecond time-resolved optical spectroscopies (e.g. broadband femtosecond transient absorption, femtosecond fluorescence up-conversion, femtosecond broadband fluorescence, vibrational sum frequency generation (VSFG), and second harmonic generation (SHG) spectroscopies).
Within SFB 677, work groups from Chemistry, Physics, and Materials Science at CAU Kiel join forces in 18 sub-projects to develop and investigate tiny light-driven molecular switches to realize new functions and functional materials. The Collaborative Research Centre has been inaugurated on 1 July 2007. The speaker is Prof. Rainer Herges of the Otto Diels Institute of Organic Chemistry. Our continuing project A1 is led jointly by Prof. Bernd Hartke, Dr. Falk Renth, and Prof. Temps, our new project B8 is led jointly by Prof. Gernot Friedrichs and Prof. Temps.
Please contact us for questions and new open positions for Ph.D. and Master/Diploma Thesis projects.
Click here for the CAU press release.
Click here for the SFB 677 homepage.
Click here for more information on project A1: "Ultrafast Dynamics of Photo-induced Switching Processes".
Click here for more information on project B8: "Spectroscopic Investigation of the Switching of Azobenzene-based Monolayers on Gold and SiO2".
New Cluster of Excellence "Materials for Life" takes a step forward
Kiel, 02 March 2011:
The joint committee for the Excellence Initiative has invited Christian-Albrechts-University Kiel (CAU) to submit a full application for the planned new Kiel Cluster of Excellence "Materials for Life (M4L)". M4L's mission is to explore new intelligent materials exhibiting complex multiple sensing and actuating properties towards medial applications. Materials scientists, physicists, chemists and medical researchers from CAU, the Fraunhofer Institute for Silicon Technology (ISIT) and the Helmholtz Centre for Materials and Coastal Research Geesthacht (HZG) join forces in a comprehensive multidisciplinary research thrust following novel bottom-up and top-down strategies.
Molecular structure, interactions and dynamics and supramolecular mechanisms at biomolecule/materials interfaces form an essential research focus in the M4L Cluster, where they are explored via advanced experimentation and first-principles theory in Research Area A1 (Prof. Dr. R. Berndt and Prof. Dr. F. Temps, Principal Investigators).
Click here for the CAU press release.
Claudia Sievers and Uta Corinna Stange reveive B.Sc. Prize, Meike Becker receives Otto Diels Diploma Prize
Kiel, 16 December 2010:
Uta C. Stange
This years Christmas Colloquium of the Kiel Division of the German Chemical Society (GDCh) saw a premiere: The first bachelor degrees in the chemistry department at CAU were celebrated with prizes going to the five best graduates. Among the winners were two students, who did their thesis work in our research group: Claudia Sievers and Uta Corinna Stange.
Claudia synthesized and characterized two new multi-chromophore azobenzene compounds which allowed her to gain insight into the mutual interactions between two or more azobenzene chromophores in a molecule by charge-transfer or exciton coupling. Uta on the other hand prepared self-assembled azobenzene-thiol monolayers on gold (111) and measured their IRRAS and IR/VIS SFG spectra. Both projects open new doors for our research in the frame of the SFB 677 "Function by Switching".
At the same time, Meike Becker won the Otto Diels diploma prize for one of two outstanding diploma degrees of the year 2010. Meike measured pCO2 and the 13CO2/12CO2 isotope ratios using cavity ring spectroscopy on a trip aboard RV Polarstern between Punta Arenas (Chile) and Bremerhaven. Her thesis work, which was funded by the Excellence Cluster "The Future Ocean", was supervised jointly by Gernot Friedrichs and Arne Körtzinger of IFM Geomar.
Congratulations to your graduations and awards!
Third Kiel Symposium on "The Future Ocean"
Kiel, 13 - 16 September 2010:
250 scientist from 18 countries gathered in Kiel this week for the "Third Bi-Annual Kiel Symposium on The Future Ocean" to discuss a broad range of interdisciplinary marine topics. Plenary lectures by Michael Grunze (University of Heidelberg) on "Chemical and Physical Cues in Marine Fouling" and by Heather C. Allen (Ohio State University) on "Molecular Organization at the Ocean Surface: Ions, Water, and the Microlayer" highlighted the ubiquitous roles played by Physical Chemistry in the Marine Environment. The accompanying mini-symposium on "Chemistry at Marine Interfaces" organized by G. Friedrichs, R. von Glasow, F. Temps, and D. Wallace featured four additional special sessions with invited and contributed talks on "Ocean-Atmosphere Coupling", "Surface Films", "Heterogeneous Processes", and "Air-Sea Gas Exchange" as well as a poster session.
Copyright: The Future Ocean
A big "Thank You" goes to all speakers, poster presenters, and participants, who came from countries as far away as Japan to report on their most recent work. Your presentations and your contributions to the lively discussion made this Symposium a great joy and success! Special thanks to Michael Grunze and to Heather Allen, who did a great job in explaining their research to an interdisciplinary audiance. And many thanks also to Barbara D'Anna, Franz Geiger, Martina Roeselova, Reinhard Zellner, Hartmut Herrmann, and Roland von Glasow for their excellent feature talks. We really enjoyed having you all in Kiel for a great meeting and hope to see you all again soon, in Kiel or elsewhere.
Click here to download the programme of the mini-symposium "Chemistry at Marine Interfaces".
Click here for a larger version of the above photograph (sorry, several people were too busy discussing the last talks and are therefore missing).
Background Information on the Oil Accident in the Gulf of Mexico
Kiel, 11 August 2010:
The explosion of the Deepwater Horizon platform on 22 April 2010 caused the second-largest man-made oil pollution of the sea and the surrounding shores ever. 780 Million Liters of crude oil flowed into the Gulf waters, where they caused severe damage to the unique ecosystems along the Louisiana coastline, in the Mississippi delta, and on the shores of the adjacent states.
The estimation of the ecological and economic consequences of the accident is highly complex and poses many challenging questions. Geologists, chemists, oceanographers, biologists, lawyers, and economists of the Kiel Cluster of Excellence "The Future Ocean" ("Der Ozean der Zukunft") share their insights into the problems involved with the stopping of the leak, the consequences of the pollution, and the future research needs in a 40 page background paper.
Click the following link to download the paper (in German language only): Die Ölkatastrophe im Golf von Mexiko
Christiana Albertina University commemorates its roots at the Bordesholm monastery with annual Faculty Prize Ceremony
Bordesholm, 11 July 2010:
Photo: Claudia Eulitz, (c) CAU Kiel
Every year on the second Sunday in July, Christiana Albertina University celebrates her roots in Bordesholm, where the university was founded in 1665. During the - by now traditional - ceremony at the monastery church, the president of CAU presents the coveted Faculty Prizes for the best Ph.D. theses of the preceding academic year. This year, CAU president Professor Fouquet presented one of the two prizes of the Faculty of Mathematics and Natural Sciences to former work group member Dr. Nina K. Schwalb. Nina earned her Ph.D. degree in 2009 with a thesis entitled "Ultrafast Electronic Deactivation Dynamics in DNA Model Systems by Femtosecond UV Fluorescence Spectroscopy".
Click here for the CAU press release with further information.
Click here to download the photo at higher resolution.
Otto Diels-Prize for best Ph.D. Theses 2009 to Dr. Claudia Bornholdt and Dr. Nina K. Schwalb
Kiel, 17 December 2009:
The Otto Diels-Prize of the Chemistry Department of Christian Albrechts University Kiel for the best Ph.D. Thesis in the academic year 2008/09 has been awarded to Dr. Nina K. Schwalb and to Dr. Claudia Bornholdt. Nina's thesis on the "Ultrafast Electronic Deactivation Dynamics in DNA Model Systems by Femtosecond UV Fluorescence Spectroscopy" established a new research field in our group, which has now developed into one of our main tasks. Claudia did her Ph.D. work on "Ligand-Driven Light-Induced Spin Cross-Over in Single Molecules at Room Temperature" in Rainer Herges' group. Both were honored for their "truly outstanding original contributions at the forefront of the Chemical Sciences". The prizes were presented to Nina and Claudia at the traditional Christmas Colloquium of the Kiel Division of the German Chemical Society (GDCh) by Prof. Thisbe K. Lindhorst.
At the same meeting, the BASF prizes for the best diplomas were awarded to Dipl.-Chem. Michelle Fernandez-Bieber and to Dipl.-Chem. Mark Feyand from the groups of Prof. Lindhorst resp. Prof. Stock. In addition, four young undergraduate students received pre-diploma prizes. The afternoon's programme featured talks by the prize winners with the traditional "Glühwein break" in between.
Through the Strait of Magellan to Punta Arenas (Chile): A premiere for the Institute of Physical Chemistry on RV "Polarstern"
30 November 2009:
Ph.D. student Peer Fietzek operating the ring-
down spectrometer aboard RV "Polarstern".
(c) The Futzre Ocean
A Cavity Ringdown (CRD) Spectrometer developed by Prof. Gernot Friedrichs and his group in the Institute of Physical Chemistry of CAU made its first trip aboard RV "Polarstern" from Bremerhaven through the Strait of Magellan to Punta Arenas in Chile. The new spectrometer has been tested in collaboration with CONTROS Systems & Solutions GmbH and Prof. Arne Körtzinger of IFM-GEOMAR. It enables marine scientists to make highly precise, on-site CO2 isotope measurements to obtain answers, as to which physical, chemical, and biological processes determine the fate of dissolved CO2 in the Earth's oceans. The development has been funded by the Kiel Cluster of Excellence "The Future Ocean".
Click here to visit Prof. Friedrichs' web site.
Kiel, 11 November 2009:
The first issue of a new CAU publication series, "uni-live-gespräche", sheds light on the current research-and-education conditions at CAU Kiel. Professors and students from eight faculties share their views on the questions that are moving them. Read their opinions on the new Bachelor/Master study courses, tuition ("Studiengebühren"), and the consequences of the desastrous underfunding of our university.
Click here for the complete issue of uni-live-gespräche.
Click here to read the Interview Prof. Temps and Chemistry & Economics student Carmen Schüler
JACS communication hot of the press (published on the web: 14 October 2009)
14 October 2009:
Highly Efficient Reversible Z − E Photoisomerization of a Bridged Azobenzene with Visible Light through Resolved S1(nπ*) Absorption Bands
Ron Siewertsen, Hendrikje Neumann, Bengt Buchheim-Stehn, Rainer Herges, Christian Näther, Falk Renth and Friedrich Temps
J. Am. Chem. Soc. 131, 15594 - 15595 (2009), DOI: 10.1021/ja906547d
The reversible Z−E photoswitching properties of the (Z) and (E) isomers of the severely constrained bridged azobenzene derivative 5,6-dihydrodibenzo[c,g][1,2]diazocine (1) were investigated quantitatively by UV/vis absorption spectroscopy in solution in n-hexane. In contrast to normal azobenzene (AB), 1 has well separated S1(nπ*) absorption bands, peaking at λZ = 404 nm and λE = 490 nm. Using light at λ = 385 nm, it was found that 1Z can be switched to 1Ewith very high efficiency, Γ = 92 ± 3%. Conversely, 1E can be switched back to 1Z using light at λ = 520 nm with ∼100% yield. The measured quantum yields are ΦZ→E = 72 ± 4% and ΦE→Z = 50 ± 10%. The thermal lifetime of the (E) isomer is 4.5 ± 0.1 h at 28.5 °C. The observed photochromic and photoswitching properties of 1 are much more favorable than those for normal AB, making our title compound a promising candidate for interesting applications as a molecular photoswitch especially at low temperatures. The severe constraints by the ethylenic bridge apparently do not hinder but favor the Z−E photoisomerization reactions.
Link to JACS Abstract Download in HTML Format Download as PDF (612 K)
"Chemie ist eine ungeheuer faszinierende Wissenschaft"
Kieler Nachrichten, 17 June 2009:
Kiel University offers more than 60 courses of studies. Prof. Temps, student advisor for chemistry students, offers his insights into why Chemistry is a tremendously fascinating subject opening a vast number of high potential fields in an interview with Martin Geist in the June 17, 2009 issue of Kieler Nachrichten.
Read the article in Kieler Nachrichten (in German)
Poster prize at International Workshop on Ultrafast Chemical Physics goes to Nina Schwalb
Glasgow, 30-31 October 2008:
Nina K. Schwalb won a poster prize at the International Workshop in Chemical Physics in Glasgow with her poster on The Relevance of Hydrogen-Bonding Dynamics in Electronically Excited DNA.
Researchers at Kiel University report sequence-dependent effects of light on DNA
CAU press release, Kiel, 10 October 2008:
DNA, the molecule that acts as the carrier of genetic information in all forms of life, is highly resistant against alteration by ultraviolet light, but understanding the mechanism for its photostability presents some puzzling problems. A key aspect is the interaction between the four chemical bases that make up the DNA molecule. Researchers at Kiel University have succeeded in showing that DNA strands differ in their light sensitivity depending on their base sequences. Their results are reported by Nina Schwalb and colleagues in the current issue of the journal Science appearing on October 10, 2008.
It has been known for many years that the individual bases that code the genetic information contained in DNA show a high degree of photostability, as the energy that they take up from UV radiation is immediately released again. Surprisingly, however, it is found that in DNA, which consists of many bases, those mechanisms are ineffective or only partially effective. It seems that the deactivation of UV-excited DNA molecules must instead occur by some completely different mechanisms specific to DNA, which are not yet understood. Through measurements by a variety of methods on DNA molecules with different base sequences, the research group led by Professor Friedrich Temps at the Institute of Physical Chemistry of Kiel University has now been able to confirm and clarify that assumption.
According to Professor Temps, "DNA achieves its high degree of photostability through its complex double-helix structure. The interactions between bases that are stacked one above another within a DNA strand, and the hydrogen bonds between the base pairs of the two complementary single strands in the double-helix play key roles. Through the different interactions that we have observed the DNA acts to some extent as its own sun-protection".
Ph.D. student Nina Schwalb investigated many different base combinations in synthetically-produced DNA molecules. Using a femtosecond pulsed laser spectroscope, she measured the characteristic energy release for each combination. She was able to measure the time for which the molecules continued to fluoresce, and thus how long they stored the light energy. She found that for some base combinations these fluorescence ‘lifetimes’ were only about 100 femtoseconds, whereas for others they were up to a thousand times longer. A femtosecond is one millionth of a billionth of a second.
Nina Schwalb adjusting her femtosecond laser spectroscope.
Photo: Jürgen Haacks, (c) Jürgen Haacks.
Can genetic information be controlled by light?
Commenting on the conclusions from her research, Nina Schwalb says: “We have investigated the photophysical properties and have found that different base combinations have widely different fluorescence lifetimes. This could lead to the development of a new diagnostic method whereby laser light could be used to directly recognise certain genetic sequences without, for example, having to mark the DNA with dyes as in the method used at present".
One might also envisage linking the photophysical properties to genetic characteristics. When these mechanisms are better understood, it might in the long term become possible to repair gene mutations using laser radiation.
"In the field of nano-electronics it has already been shown that synthetically produced DNA can be used as ‘nano-wires’. On the basis of the different reaction times of the molecules it might one day become possible to use laser pulses to ‘switch’ specific molecules. It might even be possible under some circumstances to make transistors from DNA that would work through the hydrogen bonds," explains Professor Temps.
The work of Nina Schwalb is being supported by the German Research Foundation (DFG) as part of the project “Ultrafast Photodynamics of DNA".
Click here to download above photo at higher resolution (321.8 kB).
Click here for press relase on CAU homepage.
Download Report in Kieler Nachrichten (10 Oct. 2008).
Science article hot of the press (published 10 October 2008)
10 October 2008:
Base Sequence and Higher-Order Structure Induce the Complex Excited-State Dynamics in DNA
Nina K. Schwalb and Friedrich Temps
Science 322, 243 - 245 (2008), DOI: 10.1126/science.1161651
DNA dissipates ultraviolet light more effectively when it consists of a mixed sequence than when it is an extended run of the same nucleotide.
The high photostability of DNA is commonly attributed to efficient radiationless electronic relaxation processes. We used femtosecond time-resolved fluorescence spectroscopy to reveal that the ensuing dynamics are strongly dependent on base sequence and are also affected by higher-order structure. Excited electronic state lifetimes in dG-doped d(A)20single-stranded DNA and dG·dC-doped d(A)20·d(T)20 double-stranded DNA decrease sharply with the substitution of only a few bases. In duplexes containing d(AGA)·d(TCT) or d(AG)·d(TC) repeats, deactivation of the fluorescing states occurs on the subpicosecond time scale, but the excited-state lifetimes increase again in extended d(G) runs. The results point at more complex and molecule-specific photodynamics in native DNA than may be evident in simpler model systems.
Abstract in Science Download as HTML Download as PDF Supporting Online Information
Ph.D. student Ron Siewertsen and Postdoc Falk Renth win poster prize at GDCh's 21st Conference on Photochemistry
Bielefeld, 9 October 2008:
Congratulations to Ron Siewertsen and Falk Renth, who won the poster prize at this year's 21st Conference on Photochemistry of the GDCh Division of Photochemistry with their presentation on a Time-Resolved Transient Absorption Study of the Ultrafast Dynamics of the Competing (E) - (C) and (E) - (Z) Photoisomerization of a Photochromic Furyl Fulgide.
Familie Schindler Förderpreis for outstanding Ph.D. thesis to Dr. Harald Studzinski
Bordesholm, 6 July 2008:
The 2008 Familie Schindler Förderpreis for their outstanding Ph.D. theses in Physical Chemistry has been presented to Dr. Angela Gaber and to Dr. Harald Studzinski. Harald obtained his Ph.D. in the group of Prof. Temps in 2007 with a thesis on "Ultrafast Radiationless Dynamics of Selected Electronically Excited Aromatic Molecules by Femtosecond Time-Resolved Mass Spectrometry and Photoelectron Imaging". He studied the distinctive electronic relaxation dynamics in hexa- and pentafluorobenzene and in pyrrole and a series of methyl-substituted pyrroles using a combination of novel time-resolved techniques. His work has implications for understanding the photochemistry and photophysics of DNA, the "molecule of life", and is of fundamental importance for developing organic molecule based solar cells helping to sustain our future energy needs. Angela received her Ph.D. in 2007 in the group of Prof. Grotemeyer. Both have since accepted top level R&D positions at leading industrial companies.
See the CAU press release here.
Otto Diels Prize for Chemistry Diploma 2007
Kiel, 13 December 2007:
Photo: Dr. Torsten Winkler
Dipl.-Chem. Carsten Fehling received the Otto Diels Prize of the Chemistry Department of Christiana Albertina University Kiel for his top chemistry diploma in the academic year 2006/07. He did his thesis in our work group on the "Setup and Characterization of an NIR Cavity-Ringdown Spectrometer and Investigations of Thin Films on Surfaces".
Right: Prof. Felix Tuczek and Carsten Fehling.
More photos here.
November 23: "The 2007 Night of the Profs"
Kiel, Auditorium Maximum at CAU, 23 November 2007:
Discover science - at a big CAU science party - in five lecture theatres non-stop from 8 pm to 2 am.
The 2007 Night of the Profs was a big success. The lecture halls were packed until 2 am. An audience of about two hundred, among them many high school students, university students from chemistry and different other fields, young and old scientists, and interested citizens, gathered to listen to Prof. Temps' talk on "How our DNA protects itself from UV Radiation Damage - New Insights on Hydrogen Bonds" in lecture theatre A from 1 - 2 am. Many listeners, who did not arrive early, stood in the back of the lecture hall to learn about research results on the photophysics and photochemistry of the arguably most important molecules of life, the DNA and its building blocks.
Download of pdf file "The 2007 Night of the Profs"
Ph.D. student Nina Schwalb wins poster prizes at two international conferences
Oxford, 22-27 July 2007, and Boston, 19-23 August 2007:
Nina Schwalb returned with extra luggage from two international conferences. She received the PCCP poster prize at the International Conference on Femtochemistry and Femtobiology 8 in Oxford and she won the PHYS division poster prize at the 234th National Meeting of the American Chemical Society in Boston. The ACSmeeting featured over 9 500 scientific papers and more than 15 000 registrants.
Download Femto8 poster.
Dr. Gernot Friedrichs promoted to Junior Professor
Kiel, 31 July 2007:
Gernot Friedrichs has been promoted to Junior Professor to head the Junior Research Group A6 - Changing Chemistry of the Ocean Surface in the CAU Excellence Cluster The Future Ocean.
See Prof. Friedrich's homepage.
JACS article hot of the press (published on the web 10 July 2007)
10 July 2007:
Ultrafast Electronic Relaxation in Guanosine is Promoted by Hydrogen Bonding with Cytidine
Nina K. Schwalb and Friedrich Temps
J. Am. Chem. Soc. 129, 9272 - 9273 (2007), DOI: 10.1021/ja073448+
The excited electronic state lifetime of the guanosine−cytidine (G···C) Watson−Crick (WC) base pair has been directly measured in comparison to free G and C. Measurements have been carried out in solution in chloroform, where the formation of H-bonded base pairs is strongly favored, using the technique of femtosecond fluorescence up-conversion spectroscopy. The results show that the formation of the H-bonded WC pair leads to steep acceleration of the ultrafast nonradiative electronic deactivation compared to the free nucleosides, especially G, which can be explained by an intermolecular G-to-C electron-induced proton-transfer mechanism in the excited state. The results are of vital interest for bridging the huge gap between the well-known electronic properties of the isolated nucleobases and the strikingly different dynamics of DNA molecules.
Link to JACS Abstract Download in HTML Format Download as PDF (44 K)
Dr. Jens Riedel receives 2007 Familie Schindler Förderpreis for an outstanding Ph.D. thesis in Physical Chemistry
Bordesholm, 8 July 2007:
Jens obtained his Ph.D. in 2006 with a thesis on "Investigations of Photo-Induced Molecular Dissociation Processes by Photofragment Imaging Spectroscopy", in which he applied photofragment imaging to a variety of exciting reactions, including the photo-induced N-H/N-D predissociaton processes of pyrrole and pyrrole-d1. He also developed a new Doppler-free variant for H-atom imaging. He has since moved as post-doc with Prof. Kopin Liu to the Institute of Atomic and Molecular Sciences of the Academia Sinica in Taipeh, Taiwan, which under the leadership of 1986 Nobel Laureate Prof. Yuan T. Lee has grown into a world-renowned institute.
See the CAU press release
Tiny switches with huge effects: New SFB 677 in Kiel takes off!
Kiel, 1 July 2007:
In the new Collaborative Research Centre (Sonderforschungsbereich) CRC 677 "Function by Switching" at Kiel, work groups from the Chemistry, Material Science, and Physics Departments at CAU Kiel develop tiny molecular switches driven by light to realize new functions and functional materials. The SFB, inaugurated July 1 2007, is chaired by Prof. Rainer Herges of the Otto Diels Institute of Organic Chemistry. We participate with a collaborative project led by Prof. Bernd Hartke, Dr. Falk Renth, and Prof. Temps, in which we explore the dynamics of photochromic molecular switches in solution and more complex molecular environments using femtosecond spectroscopy and by quantum chemical calculations (SFB project A1).
Read more on SFB 677 and more on subproject A1 (Hartke, Renth, Temps).
New Collaborative Research Centre for CAU Kiel
26 June 2007, Informationsdienst Wissenschaft:
Neuer Sonderforschungsbereich für Kieler Uni
DFG Press Release, 23 May 2007:
DFG bewilligt elf neue Sonderforschungsbereiche
Chemistry at the Ocean Surface
26 May 2007, Kieler Nachrichten (unizeit #42):
Chemical processes at the ocean surface are unknowns in current climate models. Physical chemists in the excellence cluster The Future Ocean in Kiel work to unravel the facts.
Download pdf (in German) "Ozean und Atmosphäre"
Chemistry at the Ocean-Atmosphere Interface
NDR 1 Radio Interview:
Interview NDR 1 on June 2007: Chemistry at the Ocean-Atmosphere Interface
Otto Diels Prize for Chemistry Diplomas 2006
Kiel, 14 December 2006:
Prof. Felix Tuczek presenting the Otto Diels prizes to Anke and Nina. Photos: S. Kastaun
Dipl.-Chem. Anke Petter and Nina Schwalb received the Otto Diels Prize of the Chemistry Department of Christiana Albertina University Kiel for the best chemistry diplomas of the academic year 2005/06. They submitted their diploma theses in December of 2005, Anke on an "Investigation of the Dynamics of the Ultrafast Z - E Photoisomerization of a Furyl Fulgide by Transient Absorption Spectroscopy" and Nina on "Time-Resolved Femtosecond Fluorescence Spectroscopy of N6,N6-Dimethyladenine".
Changing Chemistry at the Ocean Surface
Physical Chemistry in the Excellence Cluster The Future Ocean (1 November 2006):
Chemical processes at the ocean surface are unknowns in current climate models. Physical chemists in the Excellence Cluster "The Future Ocean" in Kiel working in research area A6 unravel the facts (Prof. Dr. D. Wallace and Prof. Dr. F. Temps, Principal Investigators; Prof. Dr. G. Friedrichs, JRG Leader).
Open Door at the Chemistry Department of Kiel University
Kiel, 23 September 2006:
Photos: Dr. A. Krüger
See Flyer "Tag der offenen Tür 2006" (in German).
Dr. Thomas Pancur receives Familie Schindler Förderpreis for outstanding Ph.D. thesis
Bordesholm, 8 July 2005:
Photo: Kieler Nachrichten
Thomas obtained his Ph.D. at the end of 2004 with a thesis on "Investigations of the Isomerization Dynamics of Azobenzenes and the Radiationless Deactivation of Nucleobases by Femtosecond Fluorescence Spectroscopy". His work was instrumental for the birth of the Collaborative Research Centre SFB 677 "Function by Switching" in 2007. He also layed foundations for our on-going research on the photophysics and photochemistry of DNA bulding blocks.
See newspaper article here: Dr. Thomas Pancur receives Familie Schindler Förderpreis for outstanding Ph.D. Thesis
Kieler Chemiemeile zum Jahr der Chemie 2003
Sophienhof Kiel, 14 - 17 May 2003:
Photo: S. Kastaun
Download Kieler Chemiemeile zum Jahr der Chemie 2003 and press echos.
Download booklet "Chemistry in Kiel" (in German and English).
Bunsentagung 2003 in Kiel
16 May 2003, Informationsdienst Wissenschaft:
Download complete programme:
Teil 1: Allgemeine Informationen
Teil 2: Tabellarische Vortragsübersicht
Teil 3: Kurzfassungen
Teil 4: Autorenindex
Download booklet "Chemistry in Kiel" (in German and English).
How life defends itself against UV light
11 January 2003, Kieler Nachrichten (unizeit #13):
Which strategies does nature exploit to protect the genomic information encoded in the DNA from photodamage by UV radiation - a major cause of mutations? Using sophisticated methods based on ultrafast spectroscopy, we have uncovered clever new defense mechanisms developed by evolution to protect the nucleic acid bases, which form the letters of our genetic code, from photochemical destruction.
See here for the newspaper article (in German): KN vom 11.01.2003 (unizeit # 13)
2002 BASF prize for an outstanding Ph.D. Thesis to Dipl.-Chem. Dr. Attila Kuczmann
Kiel, December 2002:
Dr. Attila Kucmann receives the BASF prize for his outstanding Ph.D. thesis on "State-Resolved Investigations of the Photo-Induced Dissociation of Methyl Nitrite and Formyl Radicals using Photofragment Velocity Map Imaging".
Inauguration of Kiel Femtochemistry Laboratory
22 March 2002, Kieler Nachrichten:
See here for the newspaper article KN vom 22.03.2002 (in German).
Otto-Diels-Prize of the Chemistry Department at Kiel 2001 goes to Dipl.-Chem. Thomas Pancur
Kiel, December 2001:
Dipl.-Chem. Thomas Pancur, who did his diploma thesis at the Institute of Physical Chemistry, where he worked in the groups of Profs. H. Mäder and F. Temps, received the Otto-Diels-Prize of the Kiel group of the German Chemical Society (GDCh) for the best diploma of the academic year 2000/2001.
Zeichen dafür, dass wir noch konkurrenzfähig sind
9 November 2001, Kieler Nachrichten:
Foto: Kieler Nachrichten
See Kieler Nachrichten press release as pdf-file (in German) here: Kieler Nachrichten vom 09.11.2001
Prof. Temps together with Alexander-von-Humboldt fellow Dr. Jie Wei aligning laser beams for a triple resonance experiment.
Bunsentagung 2003 nach Kiel vergeben
Kiel, 21 September 2000
See Kieler Nachrichten press release as pdf-file (in German): Pressemitteilung-Bunsentagung2003.
Tag der Offenen Tür der CAU am 7. Mai 2000
29 April 2000, Kieler Nachrichten:
See Kieler Nachrichten press release as pdf-file (in German): Kieler Nachrichten vom 29.04.2000.
Gottfried Wilhelm Leibniz Preis der DFG nach Kiel
4 December 1999, Kieler Nachrichten:
See Kieler Nachrichten press release as pdf-file (in German): Kieler Nachrichten vom 04.12.1999.