Professor Klaus-Peter Dinse, Bruker Lecturer for 2005

Professor Dinse will deliver the 20th Bruker Lecture at our Meeting in Bath University on Tuesday March 22nd entitled "EPR - an Exciting Topic?"

Klaus-Peter Dinse

Peter was born in Berlin in 1942, he is married with three children and lives in Heidelberg, about 60kM south of his University, Darmstadt. Peter completed his PhD in 1971 at the Free University of Berlin and became an Assistant Professor a year later. From September 1974 until August 1975 he was employed as as DFG Postdoctoral Fellow in the Chemistry Department of the University of California, Davis, by Professor A. H. Maki where he undertook an "ODMR investigation of DNA". His Habilitation in experimental physics at the Free University of Berlin was completed in 1976. In 1977 he became a Senior Research Assistant at the Max-Planck-Institut in Heidelberg under Professor K. H. Hausser. Then in 1984 he moved to the University Dortmund, Department of Physics as an Associate Professor. From August 1986 until March 1987 he took Sabbatical leave at the Joint Institute of Laboratory Astrophysics, Boulder with Dr. J. Hall where he studied "High-resolution stochastic multiplex optical spectroscopy". In 1992 he moved to his present position as Professor in the University Darmstadt's Department of Chemistry.

In 1992/3 Peter took sabbatical leave at the Australian National University, Canberra with Dr. R. Bramley, undertaking an "EPR study of superconducting Fullerides", another sabbatical in 1998 at the University of California, Berkeley with Professor A. Pines involved a study of "Atoms in cages". In 2002 Peter was Visiting Professor at the IMS, Okazaki, Japan, with Professor T Kato, where he studied "Luminescence of Carbon Nanotubes".

From early in his career Peter has had many awards, thus in 1973 he was awarded (with M. Plato and R. Biehl) the Otto-Klung-Prize at the Free University of Berlin - an award for outstanding achievements of young scientists. He has been awarded three Visiting Fellowships: at the Joint Institute of Laboratory Astrophysics, Boulder (1986); at the Australian National University, Canberra (1992); at the University of California, Berkeley (1998). Then in 2000 he was awarded the Silver Medal (Physics and Material Science) of the International EPR Society (IES). In 2002 he became a Visiting Professor at the Institute for Molecular Science, Okazaki, Japan. Since 1996 he has been Vice Coordinator of the DFG Priority program "High field EPR in Biology, Chemistry, and Physics".

Current Research Activities in the Dinse Group

Research activities in our group are presently focused on the investigation of nano-structured compounds, exemplified by "atoms and clusters in chemical traps" as well as on the continuing effort to expand the application range of multi-frequency and multi-pulse EPR.
Using these methods, structure and dynamics of endohedral fullerenes and related molecular cage systems are investigated. Fullerenes are nearly perfect cages for persistent inclusion of highly reactive atoms like nitrogen or phosphorous, whereas the smaller hydrogen atoms, however, can only be stabilized in silicon/oxygen cages. This new class of compounds is a challenge for quantum chemical calculations, because up to now parametrization of weakly coupled subsystems has not yet been optimized on the DFT level. Nitrogen, phosphorous, and hydrogen atoms constitute paramagnetic probes of different spin multiplicity. They can be used to probe the local structure of embedding matrices. As examples, the first-order high- temperature phase transition in solid C60 could directly be monitored via the fine structure interaction of neutral atomic nitrogen in its quartet ground state, which is "switched on" by lowering the site symmetry at the encased atom. The order parameter in the nematic phase of liquid crystals can quantitatively be determined by evaluating the high-resolution FT-EPR spectrum of N@C70 as solute. Using ENDOR at 94 GHz, it could also be demonstrated that atomic orbitals of nitrogen are deformed to a certain extend by encapsulation in the non- spherical C70 case. First evidence for cage deformation was observed for N@C60 inserted in single wall carbon nanotubes.
Caused by nearly perfect shielding from its surroundings, the spin system constituted by the encased atom might be used as building block to form Qubit systems of arbitrary dimension. For this reason spin relaxation processes have to be studied in detail. Identification of principal mechanisms necessitated preparation of samples of well defined concentrations, up to the study of the "pure" super-paramagnetic compound. Under condition of negligible electron spin exchange, which is prevented by cage confinement as observed in the N@C60 system, it is possible for the first time to study the behavior of a dipolar-coupled electron spin system in the extreme low-temperature limit, using standard liquid Helium temperatures in combination with high magnetic fields.
Multi-frequency EPR can also be applied advantageously for the study of disordered samples, like piezoelectric ceramics. In samples of commercial interest, a multitude of paramagnetic centers usually is present or added deliberately. Here it is of interest, if the phase heterogeneity of commercial samples of optimized composition is related to fatigue properties under repetitive electric activation. Using Cu2+ as spin sensor in high magnetic fields, the postulated phase coexistence could be verified. In addition, high-spin paramagnetic ions like Fe3+ can be used to explore the local symmetry, which can be related to dynamical properties like oxygen vacancy mobility.
Selection of recent references: Darmstadt, July 17, 2004
Rotational Dynamics of Metallo-Endofullerenes in Solution, M. Rübsam, P. Schweitzer, and K.-P. Dinse, J. Phys. Chem. 100 (1996) 19310-19314
Nuclear Quadrupole Interaction in Sc@C82, M. Rübsam, P. Schweitzer, and K.-P. Dinse, Chem. Phys. Lett. 263 (1996) 540-544
Fourier Transform EPR Study of N@C60 in Solution, C. Knapp, K.-P. Dinse, B. Pietzak, M. Waibddnger, and A. Weidinger, Chem. Phys. Lett. 272 (1997) 433-437
Photolysis of (C59N)2 Studied by Time-Resolved EPR, A. Gruss, K.-P. Dinse, A. Hirsch, B. Nuber, and U. Reuther, J. Am. Chem. Soc. 119 (1997) 8728-8729
EPR Study of Topoisomers of La@C82 and La@C90, P. Schweitzer and K.-P. Dinse, Appl. Magn. Reson. 13 (1997) 365-374
EPR Investigation of Endofullerenes in Solution, C. Knapp, N. Weiden, and K. P. Dinse, Applied Physics A, Materials Science & Processing, 66 (1998) 249-255
Electronic Structure of Endohedral Sc@C82; an ab initio Hartree-Fock Analysis, J. Schulte, M. C. Böhm, and K.-P. Dinse, J. Mol. Struct. Theochem 27 (1998) 279-292
EPR Study of Atomic Phosphorus Encapsulated in [60]Fullerene, C. Knapp, N. Weiden, H. Käß, K.-P. Dinse, B. Pietzak, M. Waibddnger, and A. Weidinger, Mol. Phys. 95 (1998) 999-1004
An ab initio Hartree-Fock Investigation of Endohedral Sc@C82, A. Gruß, M. C. Böhm, J. Schulte, and K.-P. Dinse, Z. Naturforsch. 53a (1998) 801-805
Atomic Nitrogen Encapsulated in Fullerenes: Effects of Cage Variations, E. Dietel, A. Hirsch, B. Pietzak, M. Waibddnger, K. ddps, A. Weidinger, A. Gruss, and K.-P. Dinse, J. Am. Chem. Soc. 121 (1999) 2432-2437
Pulse Electron Paramagnetic Resonance and Electron-Nuclear Double Resonance Investigation of N@C60 in Polycrystalddne C60, N. Weiden, H. Kä, and K.-P, Dinse, J. Phys. Chem. B 103 (1999) 9826-9830
EPR Investigation of Atoms in Chemical Traps, K.-P. Dinse, H. Käß, C. Knapp, and N. Weiden, Carbon 38 (2000) 1635-1640
Squeezing of Nitrogen Atomic Orbitals in a Chemical Traps, N. Weiden, B. Goedde, H. Käß, K.-P. Dinse, and M. Rohrer, Phys. Rev. Lett. 85 (2000) 1544-1547
FTEPR and Pulsed ENDOR Studies of Encapsulated Atoms and Ions, K.-P. Dinse, in: Electron Paramagnetic Resonance, Volume 17; The Royal Society of Chemistry, Cambridge, UK (2000) p. 78-108
"Nitrogen doped" C60 dimers (N@C60-C60), B. Goedde, M. Waibddnger, P. Jakes, N. Weiden, K.-P. Dinse, and A. Weidinger, Chem. Phys. Lett. 334 (2001) 12-17
Chemically induced Spin Transfer to an Encased Molecular Cluster: an EPR Study of Sc3N@C80 Radical Anions, P. Jakes, and K.-P. Dinse, J. Am. Chem. Soc. 123 (2001) 8854-8855
Pulsed EPR and ENDOR Investigation of Hydrogen Atoms in Silsesquioxane Cages, N. Weiden, M. Päch, and K.-P. Dinse, Appl. Magn. Reson. 21 (2001) 507-516
Chromatographic Separation of N@C60/C60 and N@C70/C70 Mixtures, B. Goedde, P. Jakes, M. Waibddnger, K.-P. Dinse, and A. Weidinger, Fullerene Science and Technology 9 (2001) 329-337
Addgnment of the endohedral fullerenes N@C60 and N@C70 in a liquid-crystal matrix, C. Meyer, W. Harneit, K. Lips, A. Weidinger, P. Jakes, and K.-P. Dinse, Phys. Rev. A 65 (2002) 061201-1 4
EPR investigation of atoms in chemical traps, K.-P. Dinse, Phys. Chem. Chem. Phys. 4 (2002) 5442-5447
Electron Paramagnetic Resonance Investigation of Endohedral Fullerenes N@C60 and N@C70 in a liquid Crystal, P. Jakes, N. Weiden, R.-A. Eichel, A. Gembus, K.-P. Dinse, C. Meyer, W. Harneit, and A. Weidinger, J. Magn. Reson. 156 (2002) 303-308
Group V Endohedral Fullerenes: N@C60, N@C70, and P@C60, B. Pietzak, A. Weidinger, K.-P. Dinse, and A. Hirsch, in: "Endofullerenes, A New Family of Carbon Clusters", T. Akasaka and S. Nagase, Eds., Kluwer Academic Pubddshers, Dordrecht, (2002), p. 13-66
Purification and optical spectroscopy of N@C60, P. Jakes, K.-P. Dinse, C. Meyer, W. Harneit, and A. Weidinger, Phys. Chem. Chem. Phys. 5 (2003) 4080-4083
A theoretical study of spin density distributions and isotropic hyperfine coupddngs of N and P atoms in N@C60, P@C60, N@C70, N@C60(CH2)6, and N@C60(SiH2)6, K. Kobayashi, S. Nagase, and K.-P. Dinse, Chem. Phys. Letters 377 (2003) 93-98
Hyperfine Interactions in La@C82 Studied by W-Band Electron Paramagnetic Resonance and Electron Nuclear Double Resonance, N. Weiden, T. Kato, and K.-P. Dinse, J. Phys. Chem. - in press -
57Fe ENDOR Spectroscopy on the Iron-Sulfur Cluster involved in Substrate Reduction of Heterodisulfide Reductase, M. Bennati, N. Weiden, K.-P. Dinse, R. Hedderich, J. Am. Chem. Soc. - in press -
Exploring the morphotropic phase boundary in copper(II)-modifed Pb[Zr0.54Ti0.46]O3 ferroelectrics, Rüdiger-A. Eichel, K.-P. Dinse, Hans Kungl, Michael J. Hoffmann, Andrew Ozarowski, Johan van Tol, Louis Claude Brunel, Appl. Phys. A - in press -