Sensitivity improvement in variable very high frequency EPR for applications in catalysis and protein research

高自旋过渡金属离子（TMI）在蛋白质和（光）催化反应中的重要性将通过新的可变甚高频EPR方法来表征。TMI络合物经常表现出具有多个处于高自旋态的未成对电子的顺磁性金属核。由于仪器条件的限制，对高自旋态的零场分裂的研究一直受到限制。为了解除这一限制，进一步开发和应用了具有更高检测灵敏度和应用范围的专用甚高频（263 GHz）EPR和频域傅里叶变换THz-EPR（FD-FT THz-EPR）方法。新的FD-FT THz-EPR和263 GHz EPR检测方案将使我们能够监测瞬态光诱导TMI态和催化反应中间体从GHz到THz频率的EPR。将开发基于公共领域EPR模拟软件包EasySpin的数值EPR例程，以模拟FD-EPR谱。我们的目的是应用FD-FT THz-EPR和263 GHz EPR来提供有关催化反应和蛋白质中TMI核心功能的信息，以揭示它们的结构功能关系。

High spin transition metal ions (TMIs) important in proteins and (photo) catalytic reactions will be characterized by novel variable very high frequency EPR methods. TMI complexes frequently exhibit paramagnetic metal cores with multiple unpaired electrons in high spin states. Due to instrumental constraints, investigation of high spin states exhibiting large zero field splittings (ZFS) have been limited until now. To lift this restriction, dedicated very high frequency (263 GHz) EPR and Frequency Domain Fourier Transform THz-EPR (FD-FT THz-EPR) methods with increased detection sensitivity and application range are further developed and applied. Novel FD-FT THz-EPR and 263 GHz EPR detection schemes will enable us to monitor the EPR of transient light induced TMI states and catalytic reaction intermediates from GHz to THz frequencies. Numerical EPR routines based on the public domain EPR simulation package EasySpin will be developed to simulate FD-EPR spectra. The intention is to apply FD-FT THz-EPR and 263 GHz EPR to provide information on function determining TMI cores in catalytic reactions and proteins to shed new light on their structure function relationship.