Regensburg 2019 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 77: Organic Molecules on Inorganic Substrates V: Solid-Liquid Interfaces, Self-Organization, Ordering
O 77.5: Vortrag
Donnerstag, 4. April 2019, 11:30–11:45, H9
Molar Ratio of Building Blocks in Controlling the Domain Size of an Imine-Covalent Organic Framework — •Vipin Mishra1, Vivek K Yadav2, Jayant K Singh2, and Thiruvancheril G Gopakumar1 — 1Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India — 2Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
Imine COF[1,2] (covalent organic framework) based on Schiff base reaction between p-phenylenediamine (PDA) and benzene-1,3,5-tricarboxaldehyde (TCA) is prepared on the HOPG-air interface. Using a combination of STM, AFM and XPS the microscopic formation of imine COF is confirmed. Role of the molar ratio of TCA and PDA has been explored and large smooth domains up to 2 um are formed for high TCA ratio (> 2) compared to PDA. It is also observed that the quality of imine COF is strongly influenced by the presence of water atmosphere during the Schiff base reaction. The electronic property of imine COF is understood by experiment (tunneling spectroscopy) and dispersion corrected density functional theory (DFT) calculation. It is observed that the imine COF is semiconducting in nature with a band gap of ~1.9 eV. The calculation also indicates that the frontier orbitals are delocalized over the framework of imine COF. The calculated cohesive energy shows that the stability of imine COF is comparable to that of graphene.
[1] Y. Yu et al. Chem. Commun., 2016, 52, 8317. [2] X. Lirong et al. Angew. Chem. Int. Ed., 2014, 53, 9564.