Introduction to Spectroscopy_JGH Lec

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<ul><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 1/26</p><p>Introduction to OrganicSpectoscopy</p><p>Dr. Joy Granada HofilenaAugust 7, 2010</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 2/26</p><p>Review of Some BasicsReview of Some Basics c = R x P</p><p> Angular resolution: U = 1.22 P / D radians</p><p>206,265 in a radian</p><p> E = h R</p><p> F = L / 4 T d2</p><p> AZ, El, RA, Dec, Ecliptic, Galactic</p><p> Siderial time, Hour AngleG = 6.67 x 10-8 (c.g.s)</p><p>c = 3 x 1010 cm/sec,</p><p>k = 1.38 x 10-16</p><p>h = 6.626 x 10-27</p><p>mH ~ mproton = 1.67 x 10-24 gramsme = 0.91 x 10</p><p>-27 grams</p><p>eV = 1.602 x 10-12 erg</p><p>Luminosity of Sun = 4 x 1033 erg/sec</p><p>Mass of the Sun = 2 x 1033 grams</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 3/26</p><p>The Physics of EM RadiationThe Physics of EM Radiation</p><p> Light: PR- PR = c = 2.998 x 1010 cm/s (in vacuum)</p><p>- E = hR</p><p>Photon energy (erg)</p><p>1 erg sec-1 = 10-7 Watt</p><p>h = 6.626 x 10-27 (c.g.s)</p><p>1 eV = 1.602 x 10-12 erg</p><p>- p = E / c = h / PPhoton momentum- P = h / p = h / mv deBroglie wavelength</p><p>Planck Function: BR(T)</p><p> Emission, absorption, continua</p><p> Discrete energy levels: Hydrogen</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 4/26</p><p>Telescope</p><p>Focal Plane</p><p>Slit</p><p>Spectrograph</p><p>SpectrographSpectrograph</p><p>collimator</p><p>Dispersing element</p><p>camera</p><p>detector</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 5/26</p><p>Refraction:Refraction:</p><p>Snells Law: n1 sin(H1) = n2 sin(H2)</p><p>H2</p><p>H1 n1</p><p>n2</p><p>n1 = refractive index in region 1</p><p>n2 = refractive index in region 2</p><p>n = c / v = Pvacuum / Pmedium</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 6/26</p><p>Diffraction:Diffraction:</p><p>Light spreads as U = P / dIn the far field given by L = d2 / P</p><p>d</p><p>L</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 7/26</p><p>2 slit interference</p><p>Constructive</p><p>Destructive</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 8/26</p><p>Types of Spectra:</p><p>Nebulae</p><p>Stars</p><p>Hot,</p><p>Opaquemedia</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 9/26</p><p>EMR</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 10/26</p><p>Materials responseto radiation or particles</p><p>Valence electrons</p><p>Core electrons</p><p>Atoms/molecules</p><p> E&amp;M radiation interacts with materials becauseelectrons and molecules in materials are polarizable:</p><p>(refraction, absorption)</p><p>= n+ i k</p><p>n = refraction, k= absorption</p><p> Ions, electrons and atoms incident on materials can interact with materials because</p><p>they are either charged or can scatter from atomic cores</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 11/26</p><p>Techniques and information content</p><p>Molecular</p><p>Libration</p><p>(hindered rotations)</p><p>Molecular</p><p>vibrations</p><p>Electronic</p><p>Absorption</p><p>Valence band and</p><p>shallow electronic</p><p>levels (atoms)</p><p>Deep electronic</p><p>core levels (atoms)</p><p>Microwave,</p><p>THz</p><p>Infrared,</p><p>Raman,</p><p>EELSVisible</p><p>Fluorescence</p><p>Luminescence</p><p>UV absorption</p><p>UV photoemission</p><p>Electron lossX-ray photoemission</p><p>(XPS, ESCA)</p><p>Auger Electron (AES)</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 12/26</p><p>No. of molecular vibrations:</p><p>Where : n = no. of atoms</p><p>C3H8= 3(11) - 6</p><p>= 27</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 13/26</p><p>Fundamental vibrations</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 14/26</p><p>Linear CO2</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 15/26</p><p>For CH2groups</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 16/26</p><p>Other linear molecules</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 17/26</p><p>HookesL</p><p>aw</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 18/26</p><p>Harmonic oscillator</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 19/26</p><p>Energy curve of a vibrating bond:</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 20/26</p><p>T</p><p>he IR</p><p>spectrum:</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 21/26</p><p>A</p><p>nimations:</p><p> Introduction to IRspectroscopy</p><p> The theory of IRspectroscopy</p><p> Sample IRspectra of molecules</p><p>E:\Organic Chemistry Software\PC_IR_Tutor</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 22/26 </p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 23/26</p><p>octane</p><p>CH3CH2CH2CH2CH2CH2CH2CH3</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 24/26 </p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 25/26</p><p>CH3CH2CH2CH2C CH</p><p>1-hexyne</p></li><li><p>8/3/2019 Introduction to Spectroscopy_JGH Lec</p><p> 26/26</p><p>sec-butyl alcohol</p><p>benzyl alcohol</p><p>A Comparison of Aliphatic and Aromatic Alcohols</p><p>CH3CHCH2CH3</p><p>OH</p><p>CH2-OH</p></li></ul>