Molecular Structure of 2,5,9,12-Tetraethylbenzo[f]quinolino[3,4-b][1,7]naphthyridine-6,8(5h,9h)-dione in Gas Phase from Electron Diffraction Method Supported by Theoretical Calculations

The semi-experimental molecular structure of 2,5,9,12-tetraethylbenzo[f]quinolino[3,4-b][1,7]naphthyridine6,8(5H,9H)-dione has been determined using the gas electron diffraction method in combination with the quantum chemical calculations. It was compared to X-ray diffraction data known from literature. Close to planar configuration of the frame is found to be undistorted. Conformational analysis revealed a set of isoenergetic conformers of the compound, the intramolecular interactions were characterized with the use of AIM and NCI approaches. Mean vibrational amplitudes (uij,h1) and anharmonic vibrational corrections (rij,e-rij,a) were calculated for the experimental temperature of 606 K using the quadratic and cubic force constant fields.