Tutorial sobre espectroscopia infrarroja

NESTOR E. MASSA

Corrientes, Corrientes

Workshop; Taller/ escuela sobre técnicas experimentales en el estudio de la materia condensada; 2007

Comite ad-hoc Drs. Nestor E. Massa-Ricardo Casali

Infrared  Spectroscopy Néstor E. Massa Laboratorio Nacional de Investigación y Servicios en Espectroscopía Optica-CEQUINOR Universidad Nacional de La Plata C.C. 962, 1900 La Plata, Argentina In this tutorial we will review scientific topics involving  a most important analytical tool  in which virtually any sample, crystals, liquids, solutions, pastes, powders, films, fibres, gases and surfaces can  be studied  using current      easily available accessories. Infrared spectroscopy, spanning from 20 to 13000 cm-1,  is a comprehensive tool for the quantitative study of vibrational modes  in terms of changes in  electric dipoles associated with vibrations and rotations. In addition, the electronic structure, as in  highly correlated materials  covering  from regular transition metal oxides to high Tc  cuprates, may also be probed through the interplay of external variables such as quasihydrostatic pressure, temperature, and applied magnetism fields. This   yields  information of instabilities of  great interest to solid state research. Infrared spectra are based on Fourier spectroscopy that is a powerful  technique applied to transmission as well as reflectivity measurements and built in the Michesol Interferometer. An interferogram is created  that it is Fourier transform to obtain transmission (absorption) as function of frequency. Then the optical properties are deduced  by a Kramers Kronig integration  or a dielectric simulation (using damped oscillators and plasma)  of the reflectivity spectra. This produce in a complete low energy characterization that adds to the search of novel compounds. We will also see more recent applications on biology where now the samples of interest are biomolecules, very complex systems such as protein, nucleic acid,  carbohydrate, lipid, or biomembrane structure where spectroscopic IR-microscopy help bridging data from X-ray cristallography that otherwise would be intractable. M. S. Dresselhaus. Optical Properties of Solids http://web.mit.edu/afs/athena/course/6/6.732/www/opt.pdf See for example, D. Nauman on Infrared Spectroscopy in Microbiology, Encyclopedia of Analytical Chemistry, R. A. Meyers (Ed.) , John Wiley and Sons Ltd , Chichester, (2000). Pp. 102-131.  Infrared Spectroscopy: Fundamentals and Applications B. Stuart  2004, http://media.wiley.com/product_data/excerpt/86/04708542/0470854286.pdf#search=%22introduction%20%2B%20%20infrared%22