《FTIR的基本原理与结构.ppt

Welcome to the Thermo Electron Spectroscopic Seminar Series. We would like to use this seminar presentation to tell you about many of the solutions we offer to make your analytical work better, faster, and hopefully more fun. During these presentations we will tell you about basic theory of infrared spectroscopy and current technologies and we will also tell you about our very latest innovations and share with you how these new techniques apply to your sampling requirements. Introduction of FT Theory In this theory overview we will describe the energy states we sample and briefly how a fourier transform spectrometer works. That which is common to all of Vibrational Spectroscopy - spectral identification, quantitative analysis, spectrometer design and function, use of spectral information. This brief presentation is meant to be a general overview. Several topics are further developed in subsequent presentations. Point out the low and high energy ends of the electromagnetic spectrum, from long wavelengths of light at 10^-5 cm-1 (radio waves) to 10^9 cm-1 (x-ray energy). Note from our chart that a molecule behaves differently when exposed to these different energy levels. For example when exposed to x-ray energy a molecule will undergo nuclear transitions (i.e.. lose a neutron) or when exposed to ultraviolet energy it may undergo an electronic transition (i.e. a transition to a higher electronic state). NOTE: Frequency can be measured in Hertz, or re-calculated into wavelength of the light. All these values are interrelated. We like to use something called wave number, which is basically the amount of waves per cm. The reason why IR spectroscopists use this is because it enables us to use normal numbers rather than a ZIILION or GIGA!! Mid Infrared covers the region from about 200 to 5000 cm-1 Our FT spectrometers allow us to measure transitions from the visible (25,000 cm-1) through the far-IR (50 cm-1) spectral range. These regions yield specific