Catalysis or photophysic of large flexible systems:
Results and limits of static approaches
Christophe Gourlaouen
Laboratoire de Chimie Quantique, Institut de Chimie de Strasbourg, Strasbourg, France
Mardi 5 Décembre 2023, 11H00
Bibiothèque du LCT, Couloir 12-13, 4ème étage, Campus Pierre et Marie Curie
The increase of computational capacities in recent days has allowed the full treatment of the experimental systems during computational investigations. Structures up to ca. 150-200 atoms can be treated at a full quantum level (mainly through DFT calculations) or mixed QM/MM approaches. However, such large systems present high degree of flexibilities and large surfaces accessible to solvent for which a simple treatment through a PCM may not be accurate enough. This can be illustrated through a first example, CO2 condensation on an epoxide catalyzed by a bis-Co(III)porphyrin cage. This work done in collaboration with Dr. S. Durot and Prof. V. Heitz (LSAMM, ICS, Strasbourg) have shown the cooperative effect between the two metalloporphyrins and the crucial role of the position of the chloride anion[1]. A second example concerns the absorption and emission properties of binuclear copper(I) complexes[2]. Theoretical investigations have allowed the elucidation of emission mechanism in solution and proposal for emission in solid state. However, significant differences are observed between computed and experimental emission values that can be attributed to structural (and electronic) flexibility has shown in Figure 1.
Figure 1. Structure of the bridging ligand 4 (left) and absorption spectra (right) in function of different conformations.
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References :
[1] L. Schoepff, L. Monnereau, S. Durot, S. Jenni, C. Gourlaouen, and V. Heitz, Chem. Cat. Chem. 2020, 12, 5826.
[2] A. Jouaiti, L. Ballerini, H.-L. Shen, R. Viel, F. Polo, N. Kyritsakas, S. Haacke, Y.-T. Huang, C.-W. Lu, C. Gourlaouen, H.-C. Su, and M. Mauro, Angew. Chem. Int. Ed. 2023, 62, e202305569.