Molecular Spectroscopy and Diffraction, 7.5 Credits

Contents

The course comprises two modules:
Module 1: Theory, 6,5 ECTS
Module 2, Laboratory exercises, 1 ECTS
The course will cover fundamental aspects of molecular spectroscopy, and diffraction. Techniques based on these principles are important to all fields of chemistry.

Molecular spectroscopy is primarily focused on optical spectroscopic information arising from either atomic movement -- such as infrared or Raman spectroscopies -- or electron transitions between different molecular orbitals. You will learn basic group theory to understand and predict IR and Raman spectra on a fundamental level, and to use symmetry to construct and use molecular orbital diagrams for polyatomic molecules, in order to predict and understand electronic transitions in molecules. Electronic transitions in d-block elements will also be covered.

Diffraction is a key technique for gaining atomic level information about the molecular structure in solid crystalline materials. Crystalline materials contain periodic arrangements of atoms that cause incident beams of X-rays, electrons or neutrons to produce constructive interference patterns, which in turn provide element and position-dependent information of the crystalline material. You will learn the basic principles behind diffraction, with a special focus on X-ray crystallography and its use for the study and determination of crystalline structures.

The course will be given in English on request.

Expected learning outcomes

Part 1: Molecular spectroscopy

• You should be able to identify all symmetry elements in a molecule and determine the corresponding symmetry point group.
• You should be able to use symmetry-based operations to identify all IR and Raman active modes in a molecule, and what kind of  atomic movements they correspond to.
• You should be able to use symmetry-based operations to construct molecular orbital diagrams for arbitrary molecules. You should be able to use this to predict electronic transitions.
• You should be able to use symmetry-based reasoning to determine splitting of the d-orbitals in transition metals according to crystal field theory. You should be able to use this to infer spin configuration, colour, reactivity and other information about metal-centered complexes.
• You should be able to combine crystal field theory and MO theory to use ligand field based reasoning to explain the spectroscopic series.

Part 2: Diffraction

• You should be able to explain the basic crystallographic concepts: unit cell, crystal lattices and lattice planes, symmetry operations, space groups and Miller indexes and the reciprocal space.
• You should be able to explain the difference in elastic scattering of X-rays by an electron, an atom and a unit cell in a crystalline material.
• You should be able to explain the general principles behind diffraction, constructive interference and be able to derive the Bragg relation.
• You should be able to index simple unit cell types and explain what structural features in a unit cell contribute to the positions and intensity of reflections in a diffractogram.
• You should be able to understand the differences between different common diffraction techniques and evaluate their respective advantages and disadvantages.

Part 3: laboratory practicals

• Demonstrate ability to, in writing, discuss conclusions and the knowledge and arguments underpinning these.

Required Knowledge

Fundamentals of Chemistry, 15 ECTS, or the equivalent.

Form of instruction

The course will be delivered in the form of lectures, tutorials and laboratory practicals.

Examination modes

The examination takes the form of written reports of the laboratory module and an individual written examination at the end of the course.

For the written examination, the following grades are awarded: Fail (U), Pass (3), Pass with merit (4), Pass with distinction (5) or Fail (U), Pass (G) or Pass with distinction (VG). On the lab module, the grades Fail (U) or Pass (G) are given.

For the entire course, the following grades are awarded: Fail (U), Pass (3), Pass with merit (4), Pass with distinction (5) or Fail (U), Pass (G) or Pass with distinction (VG). To pass the entire course, all examinations and obligatory tasks must have been passed.

Those who pass an examination may not take the same examination again with the aim of achieving a higher grade. A student who has taken two exams for a course or part of a course without passing, has the right to have another examiner appointed, unless special reasons speak against it (HF Chapter 6, Section 22). Requests for a different examiner are to be made to the Head of the Department of Chemistry.

Deviations from the course syllabus examination form can be made for a student who has a decision on pedagogical support due to disability. Individual adaptation of the examination form should be considered based on the student's needs. The examination form is adapted within the framework of the expected syllabus of the course syllabus. At the request of the student, the course responsible teacher, in consultation with the examiner, must promptly decide on the adapted examination form. The decision must then be communicated to the student.

Other regulations

In the event that the syllabus ceases to apply or undergoes major changes, students are guaranteed at least three examinations (including the regular examination opportunity) according to the regulations in the syllabus that the student was originally registered on for a period of a maximum of two years from the time that the previous syllabus ceased to apply or that the course ended.