Acquisition of an Electron Paramagnetic Resonance Spectrometer

化学研究仪器计划的这一奖项将帮助北卡罗来纳大学教堂山分校的化学系获得具有变温能力的电子顺磁共振(EPR)光谱仪。EPR将用于在不同的介质中进行低温、稳态实验和新的时间分辨实验，例如在聚合物薄膜、金属和半导体电极表面以及在宽温度范围的液体溶液中。电子顺磁共振波谱是一种研究含有未成对电子的分子的技术。对于这样的分子，当施加磁场时，会出现两种或更多不同的能态，当微波区域吸收量子辐射时，不同的能态之间会发生跃迁。当未成对的电子靠近带有自旋的原子核时，就会发生相互作用，导致吸收信号被分成几个分量。从这种相互作用可以推断出分子结构。电子顺磁共振波谱也用于研究反应速率和研究反应中产生的自由基中间体。

This award from the Chemistry Research Instrumentation Program will help the Department of Chemistry at the University of North Carolina at Chapel Hill acquire an Electron Paramagnetic Resonance (EPR) spectrometer with variable temperature capability. The EPR will be used to perform both low-temperature, steady-state experiments and new time-resolved experiments in diverse media such as in thin polymer films, on the surfaces of metal and semiconductor electrodes, and in liquid solution over a wide temperature range. %%% Electron paramagnetic resonance spectroscopy is a technique for studying molecules possessing unpaired electrons. For such molecules two or more different energy states arise when a magnetic field is applied, and transitions among the different occurs upon absorption of quanta of radiation in the microwave region. When an unpaired electron comes in the vicinity of a nucleus with a spin, an interaction takes place which causes the absorption signal to be spilt into several components. From this interaction molecular structure can be inferred. EPR spectroscopy is also used in studies of the rates of reactions and in studies involving radical intermediates produced in a reaction.