Purchase of a AC-80 NMR Spectrometer

这份来自化学研究仪器项目的合同将帮助哥伦比亚大学化学系获得一台AC-80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，用于检测化学诱导的动态核极化（CIDNP）。主要研究人员将使用该仪器，通过多核（1H, 13C, 31P） SS-CIDNP和TR-CIDNP，研究不同光化学系统的机制，包括：(1)光敏电子转移产生的有机自由基离子的反应；(2)亚磷酸盐和氧化膦的光化学；(3)测定酮光解胶束产生的自由基的排出率与胶束大小和自由基结构的关系；(4)胸腺嘧啶二聚体的光敏裂解在模拟光诱导损伤DNA修复的系统中；(5)定向生物大分子固体中CIDNP的研究；(6)环酮光解产生的双自由基的时间分辨CIDNP。除了上述研究之外，该仪器还将被本科生用于高级有机化学实验室、物理分析实验室、研究项目实验室、高级研究和本科生夏季研究。该仪器将连接到一个“电子智能教室”，其中包含最先进的多媒体设备，允许学生和教师根据需要将实验数据直接引入讲座、背诵和讨论小组。最后，计算机接口将用于制作模拟重要核磁共振实验的模块，学生可以通过ColumbiaNet在自己的个人电脑上访问这些模块。核磁共振（NMR）光谱是化学家用来研究分子结构的最有力的工具。它用于识别未知物质，表征分子内原子的特定排列，并研究溶液中分子之间相互作用的动力学。获得最先进的核磁共振光谱是必不可少的化学家谁正在进行前沿研究。这些核磁共振研究的结果在聚合物和催化以及生物学等领域都很有用。

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.