Purchase of a AC-80 NMR Spectrometer

化学研究仪器计划的这一奖项将帮助哥伦比亚大学化学系获得AC-80型核磁共振光谱仪，该光谱仪将作为多用户稳态(SS)和时间分辨(TR)仪器运行，用于检测化学诱导的动态核极化(CIDNP)。首席调查人员将利用该仪器，通过多核(1H，13C，31P)SS-CIDNP和TR-CIDNP，研究不同光化学体系的机理，包括(1)光敏化电子转移产生的有机自由基离子的反应；(2)亚磷酸盐和磷化氢氧化物的光化学；(3)测量胶束中酮的光解产生的自由基的出射率随胶束尺寸和自由基结构的变化；(4)在模拟DNA损伤修复的体系中胸腺嘧啶二聚体的光敏化裂解；(5)在定向生物大分子固体中寻找CIDNP；(6)环酮光解产生的双自由基的时间分辨CIDNP。除上述研究外，高级有机化学实验室、物理分析实验室、研究项目实验室、高级研究和夏季本科生研究中的本科生将使用该仪器。该仪器将被耦合到一个包含最先进的多媒体设施的“电子智能教室”中，允许学生和教职员工根据需要将实验数据直接引入讲座、复习和讨论小组。最后，计算机界面将被用来产生模拟重要的核磁共振实验的模块，学生可以在他们自己的个人计算机上通过ColumbiaNet访问这些模块。核磁共振波谱是化学家用来阐明分子结构的最有力的工具。它被用来识别未知物质，表征分子内原子的特定排列，并研究溶液中分子之间的相互作用动力学。对于正在进行前沿研究的化学家来说，获得最先进的核磁共振光谱是必不可少的。这些核磁共振研究的结果在聚合物和催化等领域以及生物学中都是有用的。

This award from the Chemistry Research Instrumentation Program will help the Department of Chemistry at Columbia University acquire an AC-80 NMR spectrometer that will operate as a multiuser steady state (SS) and time resolved (TR) instrument for the detection of chemically induced dynamic nuclear polarization (CIDNP). The Principal Investigators will employ the instrument to investigate, by multinuclear (1H, 13C, 31P) SS-CIDNP and TR-CIDNP, the mechanisms of diverse photochemical systems including (1) the reactions of organic radical ions produced by photosensitized electron transfer; (2) the photochemistry of phosphites and phosphine oxides; (3) the measurement of exit rates of radicals, produced by photolysis of ketone from micelles as a function of micelle size and radical structure; (4) the photosensitized cleavage of thymine dimers in systems that model photoinduced repair of damaged DNA; (5) a search for CIDNP in oriented biological macromolecular solids; and (6) time resolved CIDNP of biradicals produced by photolysis of cyclic ketones. In addition to the research described above, the instrumentation will be used by undergraduates in advanced organic chemistry laboratories, in physical-analytical laboratories, in research project laboratories, in senior research and in summer undergraduate research. The instrument will be coupled into an "electronic smart classroom" containing state-of-the-art multimedia facilities to allow students and faculty to introduce data directly from experiments into lecture, recitation and discussion groups on demand. Finally, the computer interface will be employed to produce modules that will simulate important NMR experiments and will be accessible to students on their own personal computers through ColumbiaNet. Nuclear Magnetic Resonance (NMR) spectroscopy is the most powerful tool available to the chemist for the elucidation of the structure of molecules. It is used to identify unknown substances, characterize specific arra ngements of atoms within molecules, and to study the dynamics of interactions between molecules in solution. Access to state-of-the-art NMR spectrometry is essential to chemists who are carrying out frontier research. The results from these NMR studies are useful in areas such as polymers and catalysis, and in biology.