B3130 - STRUTTURISTICA CHIMICA

Learning outcomes

At the end of the course the student will acquire a good knowledge of the principles of the structural investigation methods that use X-rays and other radiations of comparable wavelength

Course contents

• Elements of crystallography: symmetry, point groups, space groups, crystal systems, asymmetric unit, fractional coordinates
• International crystallographic tables. Systematic absences
• Crystalline geometry. Axes, planes, Miller indices
• Reciprocal lattice. Construction and meaning of the reciprocal lattice, relationships between the reciprocal lattice and the real lattice
• X-ray diffraction. Laue interpretation, Bragg interpretation, Ewald interpretation
• Structure factors and Fourier transforms. Atomic scattering factor, structure factor, diffracted intensity, phase problem
• Instrumentation. X-ray generators, synchrotron light, single crystal and powder diffractometer
• Single crystal X-ray diffraction. Crystallization methods, instrumentation, structure resolution by direct methods, structure refinement methods, analysis of the molecular structure and its thermal parameters. Use of the crystallographic database (Cambridge Structural Database, CSD)
• X-ray diffraction from protein crystals. Sample preparation, structure resolution methods, structural validation methods, use of the crystallographic database (PDB)
• Time-resolved X-ray crystallography. Pump-probe, diffusion-trapping
• X-ray powder diffraction. Sample preparation, instrumentation, information obtained from the diffractogram
• Quantitative analysis of powder diffraction patterns. Phase recognition for organic and inorganic molecules.
• Transmission electron microscopy (TEM). Brightfield, darkfield, high resolution images. Electron diffraction

Readings/Bibliography

Lecture slides and other teaching material distributed by the instructor. The lecture slides will be uploaded to the VLE at the beginning of the course, together with the corresponding chapters of the reference textbook.

Reference textbook:

G.H. Stout and L.H Jensen: "X-ray structure determination. A practical guide" (J. Wiley and Sons)

For students seeking additional information:

A. Immirzi, C. Tedesco: "La diffrazione dei cristalli" (Libreriauniversitaria.it)

C. Giacovazzo, H.L. Monaco, G. Artioli, D. Viterbo, G. Ferraris, G. Gilli, G. Zanotti, M. Catti: "Fundamentals of Crystallography" (Oxford University Press, USA

Teaching methods

The course is organized into lectures, computer lab exercises, and hands-on laboratory sessions, during which an introduction to the use of X-ray diffraction techniques on single crystals and powders is provided, as well as an overview of the use of crystallographic databases.

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Activities in the X-ray diffraction laboratories are part of the course. In order to participate in lab experiences, all students must have attended health and safety Modules 1 and 2 [e-learning mode at https://www.unibo.it/it/servizi-e-opportunita/salute-e-assistenza/salute-e-sicurezza/sicurezza-e-salute-nei-luoghi-di-studio-e-tirocinio] and (for the X-ray diffraction laboratory) Module 3 [in presence]. Information about Module 3 dates and locations will be published in the course website.

Assessment methods

Learning is assessed through a final examination, which aims at verifying the acquisition of the expected knowledge and skills through an oral test. The oral exam lasts approximately one hour and consists of three general questions on the topics covered during the lectures.

The final grade will be based on the ability to:

• clearly and accurately present the concepts, both in terms of content and scientific terminology;

• make connections between the acquired notions, demonstrating an understanding that goes beyond mere memorization of the subject matter.

Active participation in the computer and laboratory exercises will also contribute to the final evaluation.

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Students with learning disorders and/or temporary or permanent disabilities: please contact the office responsible (https://site.unibo.it/studenti-con-disabilita-e-dsa/en/for-students ) as soon as possible, so they can propose acceptable adjustments. The request for adaptation must be submitted to the lecturer at least 15 days before the exam date. The lecturer will assess the appropriateness of the adjustments, taking into account the teaching objectives.

 

Teaching tools

Projector, PC, white/blackboard. Graphics programs will be used to represent selected molecules. Practical sessionswill also be carried out in the laboratory.

Office hours

See the website of Emilio Parisini