Principles of Spectroscopy, Chemistry 26:160:540
1. Course description:
The course lays down the general theoretical groundwork that is necessary for the
understanding of the interaction between electromagnetic radiation (light) and matter at the
molecular level. Practical illustrations are drawn from electronic and vibrational spectroscopy,
however, the primary goal is to provide broad basis applicable to any type of spectroscopy,
from routine UV-vis absorption to multidimensional NMR. The course begins with a brief review
of quantum mechanics and proceeds to introduce the concepts of transition probability,
absorption, emission, dispersion, stimulated emission and laser action.
2. Course objectives:
The key objective of the course is to familiarize the students with the rudimentary theories
which govern the interaction between electromagnetic radiation (light) and molecules,
polymers and solids. Furthermore, the students will use scientific graphing and analysis
software which will allow them to explore the response of equations to physically important
variables and parameters. In this fashion, by combining traditional solutions with visualization,
a deeper and more intuitive understanding of the underlying physics will be achieved.
3. Relation to the program:
The research activity of several most active groups in the department revolves around the
issues of solar energy conversion, photochemistry, photovoltaics and optoelectronic materials.
There is currently course in the Chemistry Department’s graduate offerings which provides
comprehensive theoretical explanation of the light-matter interactions at the molecular level.
4. Related courses:
Two most closely related courses are 26:160:532 Molecular Quantum Mechanics and
26:160:529 Special Topics in Physical Chemistry. The course on Molecular Quantum Mechanics
(532) introduces theoretical methods used to predict the structure and static properties of
molecules, while the proposed course addresses the dynamic interaction of molecules with
light. As a result the two courses are complementary to one another. The content of the Special
Topics course 26:160:529 varies considerably from year to year depending on the interest of
the instructor. Special Topics courses typically focus on a narrow area of research while the
proposed course strives to provide broad, generally applicable foundations.
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5. Prerequisites:
Successful completion of an undergraduate chemistry program which must have included 2
semesters of Physical Chemistry courses (equivalent to 160:345 and 160:346 at RutgersNewark). Students with non-chemistry backgrounds and advanced undergraduates will be
admitted only at the discretion of the instructor.
6. Expected “learning outcomes”:
It is expected that upon the completion of this course students will have the working
understanding of light absorption and emission by molecular species, the concepts of
coherence and dephasing, radiative and no-radiative decay, electron and energy transfer. By
working understanding we mean the ability to identify, set up and solve the appropriate
equations. Furthermore, it is expected that the students will become well versed in the use of
scientific graphing and analysis software. The latter ability will developed and evaluated
through a series of graded homework assignments.
7. Relation to the “learning objectives” of the program:
The research activity of several most active groups in the department revolves around the
issues of solar energy conversion, photochemistry, photovoltaics and optoelectronic materials.
Sound understanding of the principles which govern the light-matter interaction at the
molecular level will help the students from these groups in reading pertinent scientific
literature, analyzing experimental results and developing a deeper perspective on their own
PhD research.
8. Reading material:
Required: J. L. McHale, Molecular Spectroscopy, Prentice Hall 0-13-229063-4
Recommended: Any standard undergraduate physical chemistry text, e.g., Silbey & Alberty;
Barrow; Engel & Reed
Any standard undergraduate physics text, e.g. Halliday & Resnick.
Software: IGOR Pro scientific graphing and analysis program by Wavemetrics, Inc. (the
program will be provided to the students at no cost).
9. Grading criteria:
1st midterm:
2nd midterm:
Graded homework assignments:
Final examination:
5th week
10th week
1 hour
1 hour
3 hours
10%
10%
20%
60 %
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10. Week-by-week syllabus:
Week 1
The nature of electromagnetic radiation. Part 1:
Classical Maxwell’s equations vs. corpuscular properties of photons.
Week 2
Review of quantum mechanics.
The familiar solutions (particle in the box, rigid rotor and harmonic oscillator).
The approximate methods of QM (perturbation theory and the variational
theorem).
Week 3
The nature of electromagnetic radiation. Part 2:
Polarization of light, propagation through dispersive and absorptive media,
interaction with charged particles. Quantum mechanical aspects of
electromagnetic radiation.
Weeks 4-5
Electric and magnetic properties of molecules and bulk matter.
Electrostatics, multipole moments, interaction of multipoles with the electric
field. Polarizability, induced multipoles and dielectric permittivity.
Hyperpolarizability and the non-linear optical response.
Weeks 5-9
Time dependent approach to spectroscopy.
Time-dependent perturbation theory. Coupling of the EM field and a molecular
dipole. Two-level system and the density matrix (Redfield) approach. Coherence
and dephasing. Fermi’s Golden Rule and transition probability. Oscillator
strength and the QM expression for the emission rate. The fluctuationdissipation theorem. Correlation functions and frequency spectra as Fourier
transform pairs. Spectral moments.
Week 10
Einstein coefficients and physical principles of laser action.
Absorption, spontaneous emission, stimulated emission and lasing cast in terms
of equilibrium between light and a 2-level system.
Week 11
Electronic spectroscopy.
Born-Oppenheimer approximation and Franck-Condon factors. Radiative and
non-radiative decay. Time-resolved electronic spectroscopy (absorption and
emission) and the dynamic effects. Coherence, photon-echo, the rotating frame
of reference and 2D electronic spectroscopy.
Week 12
Vibrational spectroscopy.
Infrared spectroscopy in 1 and 2D. Anharmonicity. Raman scattering, resonance
Raman scattering, coherent anti-Stokes Raman scattering (CARS).
Week 13
Energy and electron transfer processes.
Exciton coupling, the mechanisms of singlet and triplet energy transfer. Coherent
and incoherent energy transfer. Marcus-Jortner theory of electron transfer.
Applications to solar energy conversion in biological systems and materials.
Week 14
Current research topics.
To be determined by the instructor.
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