CSD-Educators: Samuel Tetteh from University of Cape Coast in Ghana

For this CSD Educators blog it is my pleasure to welcome Dr Samuel Tetteh from the University of Cape Coast, Ghana. Samuel holds a PhD in Chemistry from the University of Cape Coast and is now a teacher and researcher at the University. I first met Samuel at a workshop in Kumasi in Ghana in 2016 and it has been fantastic to see how Samuel has gone on to use the Cambridge Structural Database to provide a more visual and engaging way to teach structural chemistry to his students. Samuel also employs the CSD in his research involving the study of structural and bonding properties of transition metal complexes and has published a number of research papers in this area. In this blog Samuel will tell us more about his teaching experiences and how crystal structures have helped him revolutionalise how he teaches chemistry. Samuel will also be speaking at our Educators UGM in March so if you want to find out more or have any questions for Samuel then you can register here.

 

A photo of the participants at the DFID-funded Workshop on renewable energy at KNUST, Kumasi Ghana in 2016 that Suzanna and Samuel attended

 

From Samuel Tetteh from the University of Cape Coast, Ghana

Use of the CSD for teaching and research at the Department of Chemistry, UCC, Ghana

As a lecturer in Physical/Inorganic chemistry, the teaching of concepts in structural chemistry has been one of the challenging tasks in my profession especially in this part of the world where chemistry is mostly recognized as a mystery. Throughout my undergraduate and postgraduate days as a student of chemistry at the University of Cape Coast, I had similar challenges understanding concepts such as the valence shell electron pair repulsion (VSEPR) theory, molecular symmetry and group theory, stereochemistry, coordination chemistry and organometallic chemistry. These 3-D concepts were best illustrated on 2-D blackboards with no molecular models and the best approach was to understand the Fischer projection diagrams which could get complicated with larger molecules containing multiple stereocenters.

Therefore when I became a lecturer in 2015, I was faced with the challenge of breaking down these ideas into simple concepts so that my L100 class, with students from different backgrounds, could understand and appreciate molecular geometries like seasaw, square-planar, tetrahedra and octahedra as part of the CHE 101 course. But I was lucky to get in touch with some friends in Germany who got me a pack of inorganic atomic models to help me build some molecular models to help my teaching. I could better illustrate concepts like, how the differences of the charge on ClF4 can give rise to different structures of the corresponding molecular ions. But I lost some of the models when I had to pass the structures around the class for the students to have a feel of it.

 

  

Molecular structures of ClF4+ (seesaw) on the left and that of ClF4- (square-planar) on the right.

 

So it was a breakthrough when in 2016, I came into contact with Suzanna Ward and her team from the Cambridge Crystallographic Data Centre (CCDC) at a workshop at the Kwame Nkrumah University of Science and Technology in Kumasi, Ghana. I got introduced to excellent packages like ConQuest, Mercury and Mogul for substructure searches, molecular visualization and molecular interaction studies as well as the Frank H. Allen International Research and Education (FAIRE) program which supports structural chemistry research and education in developing countries through the use of the Cambridge Structural Database (CSD) of which I am a beneficiary. Thanks to the teaching subset on the educational resources page of the CCDC, I can access 3-D structures to illustrate concepts in fundamental chemistry, drug molecules (cisplatin) and molecular point group symmetries to teach my undergraduate classes. For my MPhil class, the CSD programs, ConQuest and Mercury have been very helpful in teaching concepts in organometallic chemistry such as trends in metal-carbonyl (M-C) bond lengths, effect of molecular geometry and auxiliary ligands on the M-CO bond as well as visualization of molecular structures such as ferrocene and other sandwiched compounds which would have been difficult to illustrate on a 2-D board.

 

 

Visualization of an organometallic molecular structure (NEGNIW) using Mercury.

 

Currently, we are starting a lab for the synthesis of transition metal complexes with anticancer activities. I can confidently say that my encounter with the CCDC has really revolutionised the teaching of structural chemistry in the Department of Chemistry of the University of Cape Coast, Ghana