High power amplifier for pulsed electron paramagnetic resonance spectrometer

脉冲电子顺磁共振波谱仪高功率放大器

• 批准号: 344970-2007
• 负责人: Mattar, Saba
• 金额: $ 4.37万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=325945
• 关键词: power; amplifier; pulsed; electron; paramagnetic

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.

此应用是升级我们现有的脉冲电子顺磁共振（EPR）通过增加一个1000瓦的功率放大器，我们可以改进现有的脉冲光谱仪。用我们现有的脉冲光谱仪，我们只能获得范围约为10.0高斯的EPR谱。因此，我们被限制在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。这种改进将提高光谱的灵敏度。光谱仪的范围从10.0高斯到大约1000.0高斯。 升级是必要的，因为申请人正在研究的分子类型具有大的核超精细分裂和大的各向异性g张量。帕斯莫尔正在合成硫和氮自由基，在固态下，它们就像分子磁铁一样。奥克利是产生无机杂环和有机自由基的主要基团，它们连接在一起形成固态导电材料。Mattar还在研究S-N杂环基团，这些基团可作为具有新磁性的化合物的构建单元。此外，他还生成顺磁性半夹心有机金属反应中间体，并在低温下将其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键合与其分子性质联系起来。J. Spray正在研究前太阳系陨石的成分，这些陨石含有碳自由基和顺磁金属合金的混合物。了解这些陨石是如何形成的，可能有助于了解宇宙早期的演化。在所有情况下，自由基的结构必须在了解其性质之前得到很好的表征。没有EPR光谱，通常不可能在分子水平上确定它们的结构。EPR是一种在不破坏自由基的情况下提供原子核未成对电子分布和环境信息的强有力的技术，只有脉冲EPR谱仪才能进行二维EPR实验，从而解析和阐明复杂自由基的结构，本研究的成功取决于脉冲高功率EPR谱仪。