Christiane Timmel

Last updated
Christiane Timmel
Born
Christiane Renate Timmel
Alma mater TU Dresden
University of Oxford (DPhil)
Awards Royal Society University Research Fellowship
Tilden Prize (2020)
Scientific career
Fields Electron Spin Resonance
Magnetoreception [1]
Institutions University of Oxford
Thesis Magnetic field effects on radical pair reactions  (1998)
Doctoral advisor Peter Hore
Website timmel.chem.ox.ac.uk OOjs UI icon edit-ltr-progressive.svg

Christiane Renate Timmel is a German chemist who is Director of the Centre for Advanced Electron Spin Resonance at the University of Oxford. [2] [3] Her group make use of electron-spin resonance to understand long-range structures in chemical and biological systems. Timmel was awarded the Tilden Prize on 2020 by the Royal Society of Chemistry for her contributions to electron spin resonance.

Contents

Early life and education

Timmel was born in Saxony, Germany. She has said she was inspired to become a scientist by her parents, a mathematician and a chemist. [4] Timmel studied physical chemistry at TU Dresden. After earning her diploma she moved to the University of Oxford, where she worked in the laboratory of Peter Hore. In 1998 she completed her doctoral degree on the effects of magnetic fields on radical pair reactions. [5]

Research and career

After graduating, Timmel was awarded a Royal Society University Research Fellowship at St Hilda's College, Oxford. In 2005 she moved to New College, Oxford [6] where she was promoted to Professor of Chemistry.[ when? ] [6] She has studied the impacts of magnetic fields on chemical interactions. For example, during radical pair mechanism, radicals are generated in a singlet or triplet state, typically by photolysis, due to the conservation of total spin angular momentum. In this reaction, the efficiency of singlet–triplet conversion is known to be impacted by magnetic fields. Timmel has shown that magnetic fields of strengths comparable to that of the Earth's magnetic field can impact the outcome of reactions. In the radical pair mechanism, Timmel has shown that the relative orientation of molecules with respect to an applied magnetic field can impact the reaction kinetics. In an effort to understand bird migration, Timmel has investigated the magnetic field responses of various proteins, including those in the photolyase and the blue-sensitive cryptochrome families. [7]

Alongside her own research, Timmel directs the Centre for Advanced Electron Spin Resonance (CAESR) at the University of Oxford, which she founded in 2007. There she develops low and zero-field equipment for electron-spin resonance, as well as pulsed and continuous-mode spectrometers. [7] Beyond her leadership of CAESR, Timmel chairs the Royal Society of Chemistry Electron Spin Resonance group. [8]

In 2020 Timmel was awarded the Royal Society of Chemistry Tilden Prize for her contributions to electron-spin resonance. [4]

Publications

Timmel's publications [2] [3] include:

Personal life

Timmel serves as a school governor at New College School in Oxford, where she was formerly a parent. [11]

Related Research Articles

<span class="mw-page-title-main">Magnetoreception</span> Biological ability to perceive magnetic fields

Magnetoreception is a sense which allows an organism to detect the Earth's magnetic field. Animals with this sense include some arthropods, molluscs, and vertebrates. The sense is mainly used for orientation and navigation, but it may help some animals to form regional maps. Experiments on migratory birds provide evidence that they make use of a cryptochrome protein in the eye, relying on the quantum radical pair mechanism to perceive magnetic fields. This effect is extremely sensitive to weak magnetic fields, and readily disturbed by radio-frequency interference, unlike a conventional iron compass.

CIDNP, often pronounced like "kidnip", is a nuclear magnetic resonance (NMR) technique that is used to study chemical reactions that involve radicals. It detects the non-Boltzmann (non-thermal) nuclear spin state distribution produced in these reactions as enhanced absorption or emission signals.

<span class="mw-page-title-main">Electron paramagnetic resonance</span> Technique to study materials that have unpaired electrons

Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the spins excited are those of the electrons instead of the atomic nuclei. EPR spectroscopy is particularly useful for studying metal complexes and organic radicals. EPR was first observed in Kazan State University by Soviet physicist Yevgeny Zavoisky in 1944, and was developed independently at the same time by Brebis Bleaney at the University of Oxford.

<span class="mw-page-title-main">Cryptochrome</span> Class of photoreceptors in plants and animals

Cryptochromes are a class of flavoproteins found in plants and animals that are sensitive to blue light. They are involved in the circadian rhythms and the sensing of magnetic fields in a number of species. The name cryptochrome was proposed as a portmanteau combining the chromatic nature of the photoreceptor, and the cryptogamic organisms on which many blue-light studies were carried out.

Spin chemistry is a sub-field of chemistry positioned at the intersection of chemical kinetics, photochemistry, magnetic resonance and free radical chemistry, that deals with magnetic and spin effects in chemical reactions. Spin chemistry concerns phenomena such as chemically induced dynamic nuclear polarization (CIDNP), chemically induced electron polarization (CIDEP), magnetic isotope effects in chemical reactions, and it is hypothesized to be key in the underlying mechanism for avian magnetoreception and consciousness.

Peter John Hore is a British chemist and academic. He is a Professor of Chemistry at the University of Oxford and fellow of Corpus Christi College, Oxford. He is the author of two Oxford Chemistry Primers on Nuclear Magnetic Resonance (NMR) and research articles primarily in the area of NMR, electron paramagnetic resonance (EPR), spin chemistry and magnetoreception during bird migration.

Magnetobiology is the study of biological effects of mainly weak static and low-frequency magnetic fields, which do not cause heating of tissues. Magnetobiological effects have unique features that obviously distinguish them from thermal effects; often they are observed for alternating magnetic fields just in separate frequency and amplitude intervals. Also, they are dependent of simultaneously present static magnetic or electric fields and their polarization.

Quantum biology is the study of applications of quantum mechanics and theoretical chemistry to aspects of biology that cannot be accurately described by the classical laws of physics. An understanding of fundamental quantum interactions is important because they determine the properties of the next level of organization in biological systems.

<span class="mw-page-title-main">Unpaired electron</span> Type of lepton that orbits an atom on its own

In chemistry, an unpaired electron is an electron that occupies an orbital of an atom singly, rather than as part of an electron pair. Each atomic orbital of an atom has a capacity to contain two electrons with opposite spins. As the formation of electron pairs is often energetically favourable, either in the form of a chemical bond or as a lone pair, unpaired electrons are relatively uncommon in chemistry, because an entity that carries an unpaired electron is usually rather reactive. In organic chemistry they typically only occur briefly during a reaction on an entity called a radical; however, they play an important role in explaining reaction pathways.

<span class="mw-page-title-main">Radical (chemistry)</span> Atom, molecule, or ion that has an unpaired valence electron; typically highly reactive

In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spontaneously dimerize. Most organic radicals have short lifetimes.

<span class="mw-page-title-main">DPPH</span> Chemical compound

DPPH is a common abbreviation for the organic chemical compound 2,2-diphenyl-1-picrylhydrazyl. It is a dark-colored crystalline powder composed of stable free radical molecules. DPPH has two major applications, both in laboratory research: one is a monitor of chemical reactions involving radicals, most notably it is a common antioxidant assay, and another is a standard of the position and intensity of electron paramagnetic resonance signals.

David Hardy Whiffen FRS was an English physicist and pioneer of infrared and Electron Spin Resonance known for the "Whiffen Effect".

Magnetochemistry is concerned with the magnetic properties of chemical compounds. Magnetic properties arise from the spin and orbital angular momentum of the electrons contained in a compound. Compounds are diamagnetic when they contain no unpaired electrons. Molecular compounds that contain one or more unpaired electrons are paramagnetic. The magnitude of the paramagnetism is expressed as an effective magnetic moment, μeff. For first-row transition metals the magnitude of μeff is, to a first approximation, a simple function of the number of unpaired electrons, the spin-only formula. In general, spin–orbit coupling causes μeff to deviate from the spin-only formula. For the heavier transition metals, lanthanides and actinides, spin–orbit coupling cannot be ignored. Exchange interaction can occur in clusters and infinite lattices, resulting in ferromagnetism, antiferromagnetism or ferrimagnetism depending on the relative orientations of the individual spins.

Klaus Schulten was a German-American computational biophysicist and the Swanlund Professor of Physics at the University of Illinois at Urbana-Champaign. Schulten used supercomputing techniques to apply theoretical physics to the fields of biomedicine and bioengineering and dynamically model living systems. His mathematical, theoretical, and technological innovations led to key discoveries about the motion of biological cells, sensory processes in vision, animal navigation, light energy harvesting in photosynthesis, and learning in neural networks.

Maria-Elisabeth Michel-Beyerle is a German chemist. From 1974 to 2000, she was a professor of Physical Chemistry at the Technical University of Munich. Among other awards, she has received the 2000 Bavarian Order of Merit, the highest service order bestowed by the Free State of Bavaria, for her work on photosynthesis.

Magnetotropism is the movement or plant growth in response to the stimulus provided by the magnetic field in plants around the world. As a natural environmental factor in the Earth, variations of magnetic field level causes many biological effects, including germination rate, flowering time, photosynthesis, biomass accumulation, activation of cryptochrome, and shoot growth.

<span class="mw-page-title-main">Wolfgang Lubitz</span> German chemist and biophysicist

Wolfgang Lubitz is a German chemist and biophysicist. He is currently a director emeritus at the Max Planck Institute for Chemical Energy Conversion. He is well known for his work on bacterial photosynthetic reaction centres, hydrogenase enzymes, and the oxygen-evolving complex using a variety of biophysical techniques. He has been recognized by a Festschrift for his contributions to electron paramagnetic resonance (EPR) and its applications to chemical and biological systems.

<span class="mw-page-title-main">Koelsch radical</span> Chemical compound

The Koelsch radical is a chemical compound that is an unusually stable carbon-centered radical, due to its resonance structures.

David Eusthatios Manolopoulos is a Professor of Theoretical Chemistry at University of Oxford. His research focuses on the computational modeling of the dynamics of elementary chemical reactions in the gas phase and quantum mechanical effects in chemical dynamics. His research highlights include work on path integral approach to molecular dynamics and chemical topics as diverse as fullerenes, ring polymers, reactive scattering, and more recently, the molecular and quantum mechanism of avian magnetoreception.

<span class="mw-page-title-main">Ilya Kuprov (scientist)</span> British physicist

Ilya Kuprov is a British physicist whose research focuses on quantum theory of magnetic processes and nuclear magnetic resonance. Kuprov is a professor of physics at the School of Chemistry of the University of Southampton, a deputy editor of Science Advances, a Fellow of the Royal Society of Chemistry, and a Fellow of the International Society of Magnetic Resonance.

References

  1. 1 2 Maeda, Kiminori; Robinson, Alexander J.; Henbest, Kevin B.; Hogben, Hannah J.; Biskup, Till; Ahmad, Margaret; Schleicher, Erik; Weber, Stefan; Timmel, Christiane R.; Hore, P. J. (2012). "Magnetically sensitive light-induced reactions in cryptochrome are consistent with its proposed role as a magnetoreceptor". Proceedings of the National Academy of Sciences. 109 (13): 4774–4779. Bibcode:2012PNAS..109.4774M. doi: 10.1073/pnas.1118959109 . ISSN   0027-8424. PMC   3323948 . PMID   22421133.
  2. 1 2 Christiane Timmel publications from Europe PubMed Central
  3. 1 2 Christiane Timmel publications indexed by the Scopus bibliographic database. (subscription required)
  4. 1 2 "Professor Christiane Timmel | Tilden Prize winner 2020". rsc.org. Royal Society of Chemistry. Retrieved 2020-11-16.
  5. Timmel, Christiane Renate (1998). Magnetic field effects on radical pair reactions. ox.ac.uk (DPhil thesis). University of Oxford. OCLC   556790900. EThOS   uk.bl.ethos.267955.
  6. 1 2 "Christiane Timmel | New College". www.new.ox.ac.uk. Retrieved 2020-11-16.
  7. 1 2 "Dr C. R. Timmel - Research Guides". research.chem.ox.ac.uk. Retrieved 2020-11-16.
  8. "RSC ESR Group – Electron Spin Resonance Spectroscopy Group of the Royal Society of Chemistry" . Retrieved 2020-11-16.
  9. Cai, Jianming; Plenio, Martin B. (2013). "Chemical Compass Model for Avian Magnetoreception as a Quantum Coherent Device". Physical Review Letters. 111 (23): 230503. arXiv: 1304.4143 . Bibcode:2013PhRvL.111w0503C. doi:10.1103/physrevlett.111.230503. ISSN   0031-9007. PMID   24476240. S2CID   22085536.
  10. Liedvogel, Miriam; Maeda, Kiminori; Henbest, Kevin; Schleicher, Erik; Simon, Thomas; Timmel, Christiane R.; Hore, P. J.; Mouritsen, Henrik (2007). "Chemical Magnetoreception: Bird Cryptochrome 1a Is Excited by Blue Light and Forms Long-Lived Radical-Pairs". PLOS ONE. 2 (10): e1106. Bibcode:2007PLoSO...2.1106L. doi: 10.1371/journal.pone.0001106 . ISSN   1932-6203. PMC   2040520 . PMID   17971869.
  11. "Who We Are". newcollegeschool.org. New College School. Archived from the original on 2017-11-21. Retrieved 2020-11-16.