98672 - CRYSTAL ENGINEERING

Learning outcomes

At the end of the course the student has acquired knowledge to design, prepare and characterize crystalline molecular materials and coordination networks and to study crystal polymorphs and co-crystals.

Course contents

The course is in English and comprises lectures provided by guest professors chosen on the basis of their specific expertise in one or more of the topics listed below.
Guest lectures are usually delivered in on-line mode and presided by professor Braga, whose lectures are delivered in the presence of all students.

The content of the course is as follows

1. Introduction. Hystorical background. When crystal engineering was born. Tutorials on most relevant techniques for the investigation of the solid state (IR and RAMAN spectroscopies, solid state NMR, X-ray diffraction, differential scanning calorimetry, TGA)

2. Intermolecular interactions in molecular crystals, amorphous substances, hydrogen bonds, halogen bonds, sigma-hole interactions, coordination bonds to construct superstructures.

3. Crystal forms. Multeplicity of crystal forms for a same substance, crystal polymorphism, hydrates, solvates, salts, co-crystals and their polymorphs

4. Crystal Polymorphism. The issue of identification, characterization, usage of crystal forms. The impact in the pharmaceutical field. Aspects related to intellectual property issues. Enantiotropic and monotropic polymorphism. Case studies.

5. Crystallization. Main techniques. From solution, from melt, The kinetic problem and the quest for the most thermodynamically stable form.

6. Solvates and hydrates. Dynamic vapour sorption. Solubility and stability of hydrates. The formation of solvates and hydrates via crystallization. Solvent removal and interconversion. Thermodynamic and calorimetric aspects. Case studies.The case of rifaximin.

7. Co-crystals. Preparation of multicomponent molecular crystals, the problem of acid-base crystals, proton transfer. mechanochemical prep. Aspects related to IP issues and patentability. The ionic co-crystals. Case studies.

8. Chirality. Chiral crystals, relationship between chirality at the molecular level and at crystal level. Racemic mixtures, racemic conglomerates, racemates. The importance of chiral resolution. Case studies.

9. Metal Organic Frameworks. Hystorical background: the relationship between coordination chemistry and coordination networks: spacers and knots. Case studies. The properties of MOF. Their industrial utilization: gas storage, catalysis in nanocavities, molecular sieves. Adsorption and desadsorption of molecules in/from MOF.

10. HOFs. Organic hydrogen bonded networks. Preparation and applications as porous materials.

The course comprises three laboratory experiences, with the participation of tutors. Participation in the lab experiences is reccomended but not compulsory.

The subjects of the three lab experiences are basically focused on

i) detecting and evaluating polymorphic transitions by applying DSC, and Xray powder diffraction methods

ii) detecting and evaluating dehydration of hydrates (TGA, DSC, Xray diffration)

iii) preparation and characterization of co-crystals (database analysis, crystallization, characterization)

iv) preparation and characterization of coordination polymers / MOF preparation (characterization)

Readings/Bibliography

Crystal Engineering. Lectures notes by Fabrizia Grepioni and Dario Braga. Available on line from UniBo web site

Crystal Engineering. A textbook. Gautam Desiraju, Jagadese Vittal, Arunachalam Ramanan. World Scientific Publishing

power point presentations provided by the teacher.

Teaching methods

The course is in English and comprises lectures provided by guest professors chosen on the basis of their specific expertise in one or more of the topics listed below.
Guest lectures are usually delivered in on-line mode and presided by professor Braga, whose lectures are delivered in the presence of all students.

Lab experiments and instrumentations. Attendance to the lab is not compulsory.

Assessment methods

The assessment is usually carried out via an oral examination.

The exam lasts between 30 and 45 minutes and proceeds as follows

question1: the student is asked to examine the output of an experiment with one of the fundamental solid state techniques discussed during the course, namely DSC, powder X-ray diffraction, TGA, DVS or a combination of these.

The student is asked to provide hypothesis on the phenomenon giving rise to the observed experimental results and also to suggest alternative or complementary techniques that could be used to confirm or corroborate the initial hypothesis

question 2 and question 3 concern broad topics of the programme listed above and are used to initiate a critical evalluation of the various aspects discussion

Upon request of the student(s) it is always possible to transfer exactly the same scheme from oral to written examination. In this case the exam will last two hours. The evaluation will be based on the reading of the elaborate delivered at the end of the allotted time. Books, computers, cellphones etc are not allowed during the exam.

Lab experiments. The attendance to the lab experiments is not compulsory. It is however, compulsory to deliver a written report based on the materials distributed to prepare the lab experiments. The lab report is required to participate in the exam. The evaluation of the lab report will be only of the type PASS / NO PASS.

In the (rare) case of "NO PASS" the student is asked to meet professor Braga and discuss with him the issues concering the elaborate.

Teaching tools

power point presentations and videos from the web

Links to further information

https://site.unibo.it/molecular-crystal-engineering/en

Office hours

See the website of Dario Braga