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

高自旋过渡金属离子（TMIs）在蛋白质和（光）催化反应中的重要作用将通过新的可变甚高频EPR方法进行表征。TMI配合物经常表现出具有高自旋态多个不成对电子的顺磁性金属核。由于仪器的限制，对具有大零场分裂（ZFS）的高自旋态的研究一直受到限制。为了消除这一限制，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和频域傅里叶变换太赫兹EPR （FD-FT太赫兹EPR）方法。新的FD-FT太赫兹EPR和263 GHz EPR检测方案将使我们能够监测瞬态光诱导TMI状态和催化反应中间体在GHz到太赫兹频率的EPR。基于公共领域EPR模拟软件包EasySpin的数值EPR程序将被开发用于模拟FD-EPR光谱。目的是利用FD-FT THz-EPR和263 GHz EPR为催化反应和蛋白质中TMI核心的功能测定提供信息，从而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.