CHEM2303: Chemical Dynamics

Course Organizer:  Prof Helen Fielding

Lecturers: Dr Simon Banks, Prof Helen Fielding and Dr Giorgio Volpe

Normal prerequisite: CHEM1301 / CHEM2301

Units: 1/2

Moodle page: http://moodle.ucl.ac.uk/course/view.php?id=1035

Aims

The aim of this course is to teach students the fundamentals of modern chemical dynamics and modern experimental methods in chemical physics.

Objectives

At the end of the course, students will be able to understand molecular potential energy surfaces, molecular collisions and light-matter interactions. The emphasis is on both developing an understanding of the underlying chemical physics principles and on learning about state-of-the-art experimental techniques.

Course Structure

  • Lectures: 27 (including worked problems)
  • Workshops: 3
  • Labs:0

Assessment

  • Exam: 80% (2 hours)
  • Lab: 0%
  • Coursework: 20%

Recommended Texts

Photophysics and Photochemistry (STB)

These lectures do not follow one specific text book or primer; however, the following books have all been used as source material and you may find some of them useful.

Photochemistry - C. E. Wayne and R. P. Wayne (Oxford Chemistry Primer) Principles of Molecular Photochemistry (An Introduction) - J. Turro, V. Ramamurthy and J. C. Scaiano. Molecular quantum mechanics - Atkins and Friedman

Reaction Dynamics (GV)

These lectures do not follow one specific text book or primer; however, the following books have all been used as source material and you may find some of them useful.

Molecular Reaction Dynamics - R. D. Levine Molecular Reaction Dynamics and Chemical Reactivity - R.D.Levine and R.B. Berstein (previous version of above text by Levine) Reaction Dynamics - M. Brouard Atkins' Physical Chemistry - 8th Edition, p 885-894

Chemical Kinetics and Reaction Dynamics, P. L. Houston (Dover)

Lasers and Laser Techniques (HHF)

These lectures do not follow one specific text book or primer; however, the following books have all been used as source material and you may find some of them useful.

Laser Chemistry, Wiley - H. H. Telle, A. Gonzalez Urena and R. J. Donovan Laser Spectroscopy, 3. Ed., Springer - W. Demtröder Molecular Quantum Mechanics, OUP - P. W. Atkins and R. Friedman Modern Spectroscopy, 4. Ed., Wiley - J. M. Holla


Course Outline

Photophysics and Photochemistry (9 lectures + 1 workshop)
Dr Simon Banks

This Module will introduce the following:

  • interaction between light and matter.
  • potential energy surfaces, electronic configurations and states.
  • vibronic excitation, transition dipole moments and selection rules.
  • fates of excited states: radiative and non-radiative processes, Jablonski and energy state diagrams.
  • quantum yields; Stern-Volmer plots.
  • Kasha’s rule; delayed fluorescence; excimer fluorescence.
  • diabatic and adiabatic representations; Landau-Zener theory.
  • deuterium isotope effect; conical intersections.
  • singlet-triplet transitions – El Sayed’s rules.
  • chemical change: dissociation; alkenes and carbonyls as exemplars of photochemical reactivity.

Reaction Dynamics (9 lectures + 1 workshop)
Dr Giorgio Volpe

This Module will introduce the following:

  • Introduction & motivation
  • Preliminaries (elementary versus complex processes, scattering and types of collisions)
  • Useful definitions (including impact parameter, reaction cross-sections)
  • Connection between impact parameter and scattering
  • Microscopic understanding of chemical reaction rates and link to thermal rate constants
  • Energy conservation
  • Reference frames and Newton’s diagrams
  • Reaction case studies (harpoon, sterically controlled reactions, long-lived intermediates)
  • Potential energy surfaces, definition, measurement and calculation, trajectory calculations (early and late barriers)
  • Experimental methods (molecular beams, reactant state selection, product state identification)
  • Case studies/additional examples

Lasers and Laser Techniques (9 lectures + problems in lecture)
Prof Helen Fielding

This Module will introduce the following:

  • Light-matter interactions: absorption, emission, polarisation, transition probabilities, spectral quantities, coherence, spectral line widths and profiles, homogeneous and inhomogeneous line broadening
  • Theory of lasers: population inversion, threshold condition, resonators, properties of laser radiation, pulsed operation, mode locking, Q switching. Implementation of laser sources: solid-state lasers, gas lasers, dye lasers. Non-linear optical techniques: phase matching, second-harmonic generation, frequency mixing, high-harmonic generation 
  • Laser spectroscopy and laser chemistry: cavity ring-down spectroscopy, laser-induced fluorescence, REMPI, Doppler-free spectroscopy, laser photolysis, pump-probe experiments