6 Jun 2023
Our paper "Dynamic nuclear polarization by two-pulse phase modulation" has been accepted for publication in JCP. The paper reports an extensive theoretical and experimental investigation of the possibilities of pulsed DNP with periodic microwave sequences.
1 Nov 2022
With a fresh PhD in her pocket, Shebha joins the group as a postdoctoral researcher. Welcome!
12 Sep 2022
Jennifer gave a tutorial on "Polarization transfer in solids" at the FGMR meeting in Karlsruhe.
25 Aug 2022
The Groupement AMPERE is launching a new initiative: the AMPERE Café. It is a series of virtual (read: CO2 neutral) get-togethers, intended to stimulate informal interactions among scientists working in the field of magnetic resonance.
Jennifer will be hosting the first two editions.
Thu. Oct 6th, 20:00 CEST: Magnetic resonance pubquiz
Thu. Nov. 17th, 20:00 CET: panel discussion "Magnetic resonance instrumentation of the future"
Sign up here
22 Aug 2022
Our work on pulsed DNP was featured in the Bunsen magazine. Here is a link to the article.
16 July 2022
We had a blast at this year's EUROMAR conference, held in Utrecht, the Netherlands. Rao, Charlotte, and Sanjay each presented a poster about their research project. Such a relief to interact with colleagues from the field in person again.
27 May 2022
The official press release is out now: Collaborative Research Center 1527 will be funded by the DFG. This brand new research initiative is centered at Karlsruhe Institute of Technology, with partners at Uni Stuttgart, Uni Kaiserslautern, and Uni Konstanz! Its aim is to drastically broaden the scope of NMR through the use of, among other things, miniaturized instruments and clever new methods. Our group is, of course, contributing research on new methods of Dynamic Nuclear Polarization.
20 Jan 2022
Rao's paper has been accepted for publication in the Journal of the American Chemical Society: Efficient Pulsed Dynamic Nuclear Polarization with the X-Inverse-X Sequence. Pulsed dynamic nuclear polarization (DNP) is a promising new approach to enhancing the sensitivity of high-resolution NMR of chemical systems in the solid state. In this paper, we introduce the X-inverse-X (XiX) DNP sequence, which clearly outperforms existing sequences. Analysis with triple-mode Floquet theory suggests that a particularly rapid transfer of polarization between electron and proton spins is responsible for the improvement. Numerical simulations and experimental data indicate that pulse lengths in the new sequence can be chosen across a broad range. This observation may prove to be crucial for the technical realization of pulsed DNP at high magnetic fields.
21 July 2021
Group photo after a picnic.
6 July 2021
Rao gave a talk about the new DNP pulse sequences at the EUROMAR conference. Xiaoxun, Charlotte, and Sanjay each presented a poster.
4 May 2021
Jennifer gave a ssNMR/DNP Zoominar about our work on pulsed DNP. Here's the link to the video of the entire session.
14 April 2021
The 3.2 mm E-free MAS probe was installed on the 800 MHz NMR spectrometer today. Bring on the wet protein samples!
1 Apr 2021
Jennifer gave a talk about DNP at this year's on-line Frühjahrssymposium organized by the JungChemikerForum. You can watch it below.
JCF Frühjahrssymposium 2021
4 Dec 2020
Charlotte defended her 6-month proposal/master thesis. Great job!
28 Oct 2020
Our new laser was installed. It is dedicated to photo-DNP.
1 Oct 2020
Sanjay joined the group as a PhD student from the Indian Institute of Technology Madras. Welcome to Konstanz!
8 Apr 2020
Charlotte Weiss successfully completed her Masterprüfung and was admitted to the fast-track PhD program. Congratulations, Charlotte!
22 Nov 2019
We just heard the news that the funding for Collaborative Research Center 969 will be renewed for another 4 years. The theme of the CRC is Chemical and Biological Principles of Proteostasis. Our group will join the CRC with a MAS NMR structural biology project.
10 Sep 2019
With the installation of the MAS probe, the 800 MHz NMR spectrometer is now ready for high-resolution solid-state NMR experiments!
24 Jul 2019
Mykhailo's paper has been published in PCCP: Analysis of the EPR spectra of transferrin: the importance of a zero-field-splitting distribution and 4th-order terms. In this paper we implement a new method to extract the distribution of zero-field-splitting parameters from the EPR spectra of the iron-transport protein transferrin. This enabled us to explain features of the spectra that have puzzled EPR spectroscopists for decades. Our method is generally applicable and promotes the effective use of multi-frequency EPR spectroscopy to study high-spin iron sites in biological systems. The article is part of the themed collection “2019 PCCP HOT Articles”.
19 Jan 2019
Kong's paper was published in Science Advances yesterday: Time-Optimized Pulsed Dynamic Nuclear Polarization. The paper reports a new DNP pulse sequence, named TOP DNP. The matching condition for electron-1H polarization transfer in TOP DNP does not depend on the microwave amplitude directly, but instead relies on the timing in a train of microwave pulses. The sequence is a major step towards the implementation of pulsed DNP in high-resolution MAS NMR.
24 Sep 2018
Janne's paper is now available on the website of PCCP: Conformation of Bis-nitroxide Polarizing Agents by Multi-frequency EPR Spectroscopy. The paper shows that EPR spectroscopy can be used to determine the conformation of a biradical while it is in the frozen-glassy matrix that is used in DNP/MAS NMR experiments. Since this conformation strongly affects the DNP efficiency, the results are highly important as a guide for the design and synthesis of future polarizing agents.
19 Feb 2018
Dr. R. Venkata SubbaRao joins the lab from India. Welcome Rao!
10 Oct 2017
My paper with Sheetal has been accepted by The Journal of Chemical Physics: Off-resonance NOVEL. The paper describes a modification of the DNP pulse sequence NOVEL with a reduced microwave power requirement. It hereby opens up a path for the implementation of pulsed DNP in high-resolution MAS NMR. The paper also explores the use of average Hamiltonian theory to describe polarization transfer from electrons to bulk 1H.
1 Oct 2017
Our paper with the group of Gaël de Paëpe in Grenoble is now online. Chemical Science: Efficient cross-effect dynamic nuclear polarization without depolarization in high-resolution MAS NMR. Compared to their bis-nitroxide counterparts, the use of heterogeneous biradicals, like TEMTriPol, as polarizing agents for DNP makes it possible circumvent the detrimental depolarization effect, which depletes the initial nuclear Boltzmann polarization by more than a factor of 2. Experimental data on the DNP performance of TEMTriPol is combined with numerical simulations of cross-effect DNP/MAS NMR to gain a physical understanding of the absence of depolarization in TEMTriPol. The tremendous gain in sensitivity is illustrated with the overnight recording of a 13C-13C correlation spectrum of natural abundance cellulose at 800 MHz.