Upgrade of ESR Facility

哥伦比亚大学化学系将利用这一奖励购买两台电子自旋共振(ESR)光谱仪的升级。这两台仪器都能够在稳态操作和时间分辨ESR实验中获取ESR谱。还将实施傅里叶变换(FT)ESR方法。这两台仪器都将配备能够提供纳秒脉冲的激光，用于激发样品和产生顺磁瞬变。这些仪器将被部门成员用于广泛的工作，并将用于各种最先进的实验，包括：1)使用时间分辨激光闪光灯的气相实验光解研究利用圆偏振光产生反应产物的电子自旋极化的可能性；2)研究新型材料磁特性的低温实验；3)用时间分辨方法研究了有机三重态和自由基的电子极化转移，阐明了电子交换的机理。顺磁性物种之间；4)低温电子自旋回波包络调制(ESEEM)实验研究光合作用反应中心。电子自旋共振(ESR)光谱仪是一种用于获取分子的分子和电子结构信息的仪器。它还可以用来获得有关自由基寿命的信息，这些自由基通常是启动肿瘤生长和/或各种化学反应所必需的。

The Department of Chemistry at Columbia University will use this award for the purchase of an upgrade for two electron spin resonance (ESR) spectrometers. Both instruments are capable of acquiring ESR spectra in steady state operation and in time-resolved ESR experiments. Fourier transform (FT) ESR methods will also be implemented. Both instruments will be equipped with lasers capable of providing nanosecond pulses for excitation of samples and the production of paramagnetic transients. The instruments will be used by members of the department for a wide range of work and will be used for a variety of state-of-the-art experiments including: 1) Gas phase experiments employing time resolved laser flash photolysis to investigate the possibility of employing circularly polarized light to produce electron spin polarization of reaction products; 2) Low temperature experiments which investigate the magnetic characteristics of novel materials; 3) Room temperature solution experiments which employ time resolved methods to investigate electron polarization transfer for organic triplet states and radicals in order to elucidate the mechanism of electron exchange between paramagnetic species; and 4) Low temperature electron spin echo envelope modulation (ESEEM) experiments to investigate photosynthetic reaction centers. %%% An electron spin resonance (ESR) spectrometer is an instrument used to obtain information about the molecular and electronic structure of molecules. It may also be used to obtain information about the lifetimes of free radicals which are often essential for the initiation of tumor growth and/or a variety of chemical reactions.