High power amplifier for pulsed electron paramagnetic resonance spectrometer

这项应用是对我们现有的脉冲电子顺磁共振(EPR)光谱仪进行升级，在其上增加一个1000W的功率放大器。使用我们目前的脉冲光谱仪，我们只能获得范围约为10.0高斯的EPR光谱。因此，我们仅限于具有非常小的超精细分裂和小的各向异性g张量的有机自由基。但这次升级将使光谱仪的光谱范围从10.0高斯增加到大约1000.0高斯。因此，升级是必要的，因为申请者研究的分子具有大的核超精细分裂和大的各向异性g张量。J.Passmore正在合成硫和氮自由基，这些自由基在固态下充当分子磁体。R.Oakley正在生成主要基团的无机杂环和有机自由基。当它们连接在一起时，可以形成固态导电材料。S.Mattar还在研究S-N杂环自由基，这些杂环自由基可以作为具有新磁性的化合物的构建块。此外，他还产生顺磁性半夹心有机金属活性中间体，并在低温下将它们隔离在惰性气体基质中。这三位研究人员都将化合物的结构和成键与其分子性质联系起来。J·斯普莱姆正在研究太阳前陨石的成分，这些陨石含有碳自由基和顺磁性金属合金的混合物。了解这些陨石是如何形成的，可能有助于揭示宇宙在早期阶段的演化。在所有情况下，在了解它们的性质之前，必须很好地表征这些自由基的结构。如果没有EPR光谱，通常不可能在分子水平上确定它们的结构。EPR是一种强大的技术，它在不破坏自由基的情况下提供关于未配对电子分布和原子核环境的详细信息。只有使用脉冲EPR光谱仪才能进行二维(2D)EPR实验，其中复杂自由基的结构可以被解析和阐明。我们研究的成功取决于脉冲高功率EPR光谱仪。

This application is to upgrade our existing pulsed electron paramagnetic resonance (EPR) spectrometer by adding to it a 1000 Watt power amplifier.  With our present pulsed spectrometer we can only acquire EPR spectra that have a range of approximately 10.0 Gauss.  Thus we are limited to organic free radicals that have very small hyperfine splittings and small anisotropic g tensors.  This upgrade will increase the spectral range of the spectrometer from 10.0 to approximately 1000.0 Gauss.    The upgrade is essential since the type of molecules the applicants are studying have large nuclear hyperfine splittings and large anisotropic g tensors.  J. Passmore is synthesizing sulfur and nitrogen free radicals that, in the solid state, act as molecular magnets.  R. Oakley is generating main group inorganic heterocyclic and organic free radicals.  When linked together they form solid state conducting materials.  S. Mattar is also studying S-N heterocyclic radicals that act as building blocks for compounds with novel magnetic properties. In addition, he generates paramagnetic half-sandwich organometallic reactive intermediates and isolates them in inert gas matrices at low temperatures. All three researchers correlate the structure and bonding of their compounds to their molecular properties. J. Spray is studying the composition of meteorites that are of pre-solar origin and contain mixtures of carbon free radicals and paramagnetic metal alloys. Understanding how these meteorites are formed may shed light on the evolution of the universe in its early stages.  In all cases, the free radical structures must be well characterized before their properties are understood.  Without EPR spectroscopy determination of their structures at the molecular level is not usually possible. EPR is a powerful technique that provides detailed information about the unpaired electron distribution and the environment of the nuclei without destroying the free radical.  Only with a pulsed EPR spectrometer can two-dimensional (2D) EPR experiments be performed where the structure of complex free radicals can be resolved and elucidated.  The success of our research is contingent on a pulsed high power EPR spectrometer.