Lecture 9 Vibrational Spectroscopy. Only photons of one specified wavelength are absorbed Ground state Excited state.

Slides:

Advertisements

Similar presentations

Raman Spectroscopy A) Introduction IR Raman

Advertisements

EE 230: Optical Fiber Communication Lecture 5 From the movie Warriors of the Net Attenuation in Optical Fibers.

METO 621 Lesson 6. Absorption by gaseous species Particles in the atmosphere are absorbers of radiation. Absorption is inherently a quantum process. A.

INDEX OF HYDROGEN DEFICIENCY THE BASIC THEORY OF THE BASIC THEORY OF INFRARED SPECTROSCOPY and.

Lecture 6 Vibrational Spectroscopy

Rotational Spectra Simplest Case: Diatomic or Linear Polyatomic molecule Rigid Rotor Model: Two nuclei joined by a weightless rod J = Rotational quantum.

Vibrational Spectroscopy I

Spectrum from a Prism. Example of a Spectrum Kirchoff’s Laws.

Spectroscopy. Atoms and Light  Atomic electron energy levels are a source of discrete photon energies.  Change from a high to low energy state produces.

Vibrational Spectroscopy CHE 626 Alex Nazarenko

Test #1, Wednesday, Feb 10 I will post a review for Test 1 in the A101 homepage under the link to “Lectures” this week. I will tell you the topics to review.

Lecture 11 Atomic absorption. Only photons of one specified wavelength are absorbed Ground state Excited state.

Rotational Spectra Simplest Case: Diatomic or Linear Polyatomic molecule Rigid Rotor Model: Two nuclei joined by a weightless rod J = Rotational quantum.

Photons of Light The smallest unit of light is a photon A photon is often called a particle of light The Energy of an individual photon depends on its.

Introduction to Infrared Spectrometry Chap 16. Infrared Spectral Regions Table 16-1 Most used – 15.

PHOTONS IN CHEMISTRY OUT. PHOTONS IN CHEMISTRY OUT WHY BOTHER?

Advanced Higher Chemistry Unit 1 Spectroscopy. Spectroscopy  Spectroscopy is used to give information regarding the structure of atoms or molecules.

Lecture 3 INFRARED SPECTROMETRY

Spectral Regions and Transitions

Physics and the Quantum Model

Wave Nature of Light and Quantum Theory

Solar Spectrum. Bit of Administration …. c = 3 x 10 8 m/sec = 3 x 10 5 km/secc = 3 x 10 8 m/sec = 3 x 10 5 km/sec Reading Reading –BSNV pp

Light. Light Terminology Which is not a measure we use to identify a type of light? A. Wavelength B. Speed C. Frequency D. Energy.

Lecture 6 Raman spectra of carbon nanotubes. Infrared (IR) spectroscopy IR 700 nm3500 nm400 nm Visible light IR IR spectra can be used to identify the.

Spectroscopic Analysis Part 4 – Molecular Energy Levels and IR Spectroscopy Chulalongkorn University, Bangkok, Thailand January 2012 Dr Ron Beckett Water.

Pat Arnott, ATMS 749, UNR, 2008 Chapter 9: Absorption by Atmospheric Gases Visible and UV Absorption: due to electronic transitions. Monatomic - polyatomic.

Vibrational and Rotational Spectroscopy

Electromagnetic Radiation

© 2010 Pearson Education, Inc. Light and Matter: Reading Messages from the Cosmos.

1 Part III Physical Chemistry III Points and credit: Approximately 20% for quiz & homework 80% final examination Note*Extra.

Electromagnetic Spectrum The emission of light is fundamentally related to the behavior of electrons.

Electromagnetic Radiation. Is light a wave or a particle? Yes It’s both, and neither At atomic scales, we have no exact analogs for phenomena For some.

1.1 Introduction Energy of IR photon Near IR 12, cm -1 Mid IR cm -1 Far IR cm -1 Energy of IR photons insufficient to cause.

5. Vibrations in Molecules

The Nobel Prize in Physics 1930 "for his work on the scattering of light and for the discovery of the effect named after him" Sir Chandrasekhara Venkata.

Lecture 2 INTRODUCTION TO SPECTROMETRIC METHODS Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Spectroscopy and electromagnetic waves. Polarisability of Matter.

Chapters: 3and 4. THREE MAIN LIGHT MATTER INTERRACTION Absorption: converts radiative energy into internal energy Emission: converts internal energy into.

Chapter 6 An Introduction to Spectrometric Methods Spectrometric methods are a large group of analytical methods that are based on atomic and molecular.

Introduction to Spectroscopy Yongsik Lee.

Spectroscopy and Atomic Structure Ch 04.

Raman Spectroscopy A) Introduction IR Raman

Electronic Structure of Atoms Chapter 4 Electronic Structure of Atoms.

1.1 What’s electromagnetic radiation

1 Aims of this lecture The diatomic chain –final comments Next level of complexity: –quantisation – PHONONS –dispersion curves in three dimensions Measuring.

Spectroscopy and Atoms

Infrared Infrared radiation extends from the nominal red edge of the visible spectrum at 700 nanometers (nm) to 1 mm. NameWavelength Gamma rayless than.

modes Atomic Vibrations in Crystals = Phonons Hooke’s law: Vibration frequency   f = force constant, M = mass Test for phonon effects by using isotopes.

Rotation and vibration spectra. Rotational States Molecular spectroscopy: We can learn about molecules by studying how molecules absorb, emit, and scatter.

An introduction to Spectrometric Methods. Spectroscopy Definition Spectroscopy is a general term for the science that deal with the interactions of various.

Electromagnetic Radiation. Waves To understand the electronic structure of atoms, one must understand the nature of electromagnetic radiation. The distance.

MOLECULAR SPECTROSCOPY

Absorption Spectroscopy

Infra-Red (IR) Spectroscopy Vibrational spectroscopy

PHYS 172: Modern Mechanics Lecture 14 – Energy Quantization Read Summer 2012.

MET 4430 Physics of Atmospheres Lecture 4 More Radiation 28 SEP-08 OCT 2012.

Vibrational frequency :

Spectroscopy and Atoms

Introduction and Principle of IR Spectrophotometry

Physics and the Quantum Mechanical Model

Spectroscopy Copyright © Houghton Mifflin Company. All rights reserved.

Raman Spectroscopy A) Introduction IR Raman

Lecture 8 Detectors Spectrophotometer design Background correction

Raman Scattering ——CCl4 molecular Raman Spectrum 崔婧

Chapter 5: Electrons in Atoms

Chapter 9: Absorption by Atmospheric Gases

Electromagnetic Radiation

Computation of Harmonic and Anharmonic Vibrational Spectra

CHEM I, Discussion 4-1 Atomic Spectra & the Bohr Model

Harmonic Oscillator.

Presentation transcript:

Lecture 9 Vibrational Spectroscopy

Only photons of one specified wavelength are absorbed Ground state Excited state

Width Doppler Speed of light 300,000,000 m/s Velocity of a particle >1000 m/s collisions Approximately as Doppler Both effects increase with the temperature and decrease with the size of the molecule/atom Multiple energy levels Width is around nm in visible area

Energy levels of ground state Energy levels of excited state Energy sublevels

A primitive rule: Molecular spectra - wide bands Atomic spectra - narrow lines

Dissociation energy Energy level/ vibrational quantum number 2 - real (anharmonic) oscilator 1 - ideal (harmonic) oscilator

a1a1 1CH 2 s-str SSgas SS a1a1 2CO str VSVSgas WW a1a1 3CH 2 scis SSgas MM b1b1 4CH 2 a-str VSVSgas2866 WW b1b1 5CH 2 rock SSgas b2b2 6CH 2 wag SSgas Raman IR

Frequency Wavenumber

Carbon Monoxide in gas

Rayleigh scattering No changes!

Raman scattering Escaping photon has smaller energy because the molecule did not return to the ground state

Raman scattering