Solid-State Nuclear Magnetic Resonance (NMR) Spectroscopy of Unreceptive Nuclei from Across the Periodic Table

点击翻译按钮获取中文摘要

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, and partial co-funding from the Solid State and Materials Chemistry Program in the Division of Materials Research, Professor Robert Schurko and his group at Florida State University are working to expand the range of applicability of solid-state nuclear magnetic resonance (SSNMR), an important tool for the analysis of a wide range of chemical compounds, biological samples, and advanced materials. Many kinds of atoms potentially observable with SSNMR are said to be unreceptive, meaning that data acquisition can take days, weeks, or even months to complete. The new methods being developed by the Schurko group accelerate the NMR experiments greatly, thereby expanding our ability to characterize the molecular level structures of materials important to society. This increase in understanding can, in turn, lead to improved pharmaceuticals, catalysts, nanoparticles, energetic materials, and other materials. Undergraduate and graduate students engaged in this research receive interdisciplinary training in state-of-the-art measurement science. Dr. Schurko is also involved in STEM outreach activities at the National High Magnetic Field Laboratory (MagLab), where he is the Director of the NMR and Magnetic Resonance Imaging User Program. These efforts seek to inform the general public about NMR, and include MagLab internship programs for high school students, K-12 Research Experiences for Teachers, and the Magnet Academy Program. These programs engage diverse groups of people from different socioeconomic backgrounds. The Schurko group focuses on the development and application of new methods for the acquisition of high-quality SSNMR spectra with ultra-wideline patterns originating from unreceptive nuclei from elements across the periodic table, aiming at maximizing uniform signal, reducing data acquisition times, and improving ease of execution for end users. Protocols are being developed to carefully monitor nuclear spin behavior via a combination of experiments and simulations. New pulse sequences and experimental protocols are targeting spin-1/2, integer-spin, and half-integer spin nuclei in the general areas of direct excitation/direct detection, broadband cross polarization, and indirect detection methods. This research requires careful consideration of pulse durations and timings, and the use of specially designed frequency-swept pulses. Projects targeting the most unreceptive nuclei exploit ultra-high magnetic fields – including the 35.2 Tesla series-connected hybrid magnet. All new methods are made available to researchers from many disciplines (both experts and non-experts), who can use them for structural characterization of solid materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.