Fourier-Transform Raman and Infrared Spectroscopy

傅里叶变换拉曼光谱实验正在引入到化学和生物化学专业和其他高层次的科学学生的几个实验室。 更高的分辨率（约0.1厘米-1）和近红外范围的新FT拉曼仪器允许更复杂的实验。对于生物化学实验室，学生们在一个新的实验中使用拉曼光谱来研究分散在水中的合成磷脂双分子层。学生将通过观察CH和CC拉伸区域的强度，监测二棕榈酰磷脂酰胆碱双层内部烃链结构从有序到无序的变化。研究胆固醇作为添加剂的作用，让学生了解更多关于细胞膜的结构。在分析化学实验中，学生使用拉曼光谱学，通过内标法研究标准二甲苯混合物的组成。他们还将比较拉曼和红外光谱的采样容易程度。对于物理化学实验室，将扩大红外光谱分析振转带的范围。作为分析HCl中两种氯同位素在气相振动-旋转吸收带中的旋转结构的经典实验的替代方案，现在学生可以对HBr中的溴同位素进行类似的实验。改进的近红外能力有助于研究HCl或HBr光谱中的泛音，从而绘制势阱的下部，并发现键长如何随振动激发而变化。对于学生在先进的分析和物理实验室，一个新的实验比较拉曼和红外光谱的顺式和反式异构体的1，2-二氯乙烯提供的数据用于分配所有1,2个振动基本的每一个异构体。新仪器的红外和拉曼特征都支持研究生的研究。该仪器为学生提供了对振动光谱学的理论和应用有更广泛，更深入理解的机会。

Fourier transform-Raman spectroscopic experiments are being introduced into several laboratories for chemistry and biochemistry majors and other upper-level science students. The higher resolution (about 0.1 cm-l) and near-infrared range of the new FT-Raman instrument permit more sophisticated experiments. For the biochemistry laboratory, students use Raman spectroscopy in a new experiment to study synthetic phospholipid bilayers dispersed in water. Students will monitor the change from ordered to disordered structure in the hydrocarbon chains in the interior of dipalmitoylphosphatidylchloine bilayers as a function of temperature by observing intensities in the CH and CC stretching regions. The effect of cholesterol as an additive is studied allowing students learn more about the structure of cell membranes. In the analytical chemistry laboratory students use Raman spectroscopy to study the composition of a standard xylenes mixture using the method of internal standards. They will also compare the ease of sampling for Raman and infrared spectroscopies. For the physical chemistry laboratory, the scope of analyzing vibration-rotation bands by infrared spectroscopy will be extended. As an alternative to the classic experiment of analyzing the rotational structure due to the two chlorine isotopes in HCl in the gas-phase vibration-rotation absorption band, it is now possible for students to do a similar experiment on the bromine isotopes in HBr. The improved near-infrared capability facilitates the study of overtones in the HCl or HBr spectrum and thus mapping the lower part of the potential well and finding how the bond length varies with vibrational excitation. For students in the advanced analytical and physical laboratory, a new experiment comparing the Raman and infrared spectra of the cis and trans isomers of 1,2-dichloroethylene provides data used to assign all twelve of the vibrational fundamentals of each of the isomers. Both the infrared and Raman features of the new instrument support und ergraduate student research. This instrumentation provides opportunities for students to have a broader, deeper understanding of the theory and application of vibrational spectroscopy.