About the Seminar:

Electron Paramagnetic Resonance Imaging (EPRI) stands to vastly improve the capabilities of non-invasive medical imaging techniques by harnessing the sensitivity of electronic spins. In order for this technique to reach viability, a fundamental understanding of how to design the necessary imaging agents is imperative. Much research has been conducted into EPRI imaging agents using organic radicals. However, metal complexes may allow for EPRI to be conducted at high magnetic fields with low-frequency microwave radiation. Additionally, the synthetic tunability afforded in metal complexes provides an abundance of ways to control the electronic structure, and thus the EPR spectra. Some key challenges that need to be overcome before metal-based EPRI can be realized are broad EPR spectral linewidths, tailoring zero-field splitting in clathrochelates, and an understanding how do design molecules for specific bioimaging purposes. A series of Cr(III) tris-diamine complexes were investigated with L-band (1.36 GHz) EPR to understand how the ligand shell controls spectral linewidth. A series of Ni(II) clathrochelates were studied with magnetometry to determine the degree of zero-field splitting tunability at peripheral locations. Two Mn(II) clathrochelates were examined with X-band EPR to understand how to design a viscosity sensitive EPR probe. The results of these studies will be discussed.