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MO: Fachverband Molekülphysik

MO 2: Theory: Quantum Chemistry and Molecular Dynamics

MO 2.4: Talk

Monday, March 14, 2011, 11:15–11:30, MER 02

Ab initio and DFT Calculations of the structure, properties and aromaticity of HATN derivates — •Florian Habecker and Thorsten Klüner — Carl von Ossietzky Universität Oldenburg, Ammerländer Heerstr. 114-118, 26129 Oldenburg, Germany

In this study the aromatic heterocyclic compounds hexaazatrinaphtylene (dihydrodiquinoxalio[2,3-a:2’,3’- c]phenazine, HATN) and its sixfold methylatet derivate (2,3,8,9,14,15-hexamethyldiquinoxalio[2,3-a:2’,3’-c]phenazine, HATNMe₆) together with their anti-aromatic derivates 5,18-dihydrodiquinoxalio[2,3-a:2’,3’-c]phenazine (H₂HATN) and 2,3,8,9,14,15-hexamethyl-5,18-dihydrodiquinoxalio[2,3-a:2’,3’- c]phenazine (H₂HATNMe₆) have been investigated by ab initio and density functional theory (DFT) calculations. Different methods, such as HF, MP2 and various functionals (B3LYP, PBE and PBE0) were applied with various basis sets, e.g. 6-31G*, 6-311G**, cc-pVDZ and cc-pVTZ, respectively. The aim was to determine the structure and properties of all four heterocyclic compounds and to gain insight into the selective, reductive N-hydrogenation of one bisazine moiety of the hexaazatrinaphtylene derivates, especially concerning the formation of an antiaromatic system. Hence, calculations of the ultraviolet-visible and the infrared spectrum on PBE0/cc-pVDZ level were carried out, too. Additional calculations of the structural phenazine unit of the HATN derivates were performed revealing similar results concerning the structural and electronic alterations. Therefore, our theoretical findings are valid for a large group of derivates of the phenazine structure.