High power amplifier for pulsed electron paramagnetic resonance spectrometer

本应用是通过增加一个1000瓦功率放大器来升级我们现有的脉冲电子顺磁共振（EPR）光谱仪。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，我们仅限于有机自由基具有非常小的超细分裂和小的各向异性g张量。这次升级将使光谱仪的光谱范围从10.0增加到大约1000.0高斯。升级是必不可少的，因为申请者正在研究的分子类型具有大的核超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，它们在固态下起着分子磁铁的作用。R. Oakley主要生成无机杂环自由基和有机自由基。当它们连接在一起时，就形成了固态导电材料。S. Mattar也在研究S-N杂环自由基，它可以作为新型磁性化合物的基础。此外，他还生成了顺磁性半夹层有机金属反应中间体，并在低温下将其分离在惰性气体基质中。三位研究人员都将化合物的结构和键与分子特性联系起来。J. Spray正在研究前太阳起源的陨石的组成，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了解宇宙早期阶段的演化。在所有情况下，必须先对自由基的结构进行很好的表征，然后才能了解它们的性质。没有EPR光谱法，在分子水平上确定它们的结构通常是不可能的。EPR是一种强大的技术，它可以在不破坏自由基的情况下提供有关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，从而可以解析和阐明复合自由基的结构。我们研究的成功取决于一台脉冲大功率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.