Planar and Nonplanar Unsaturation. Preparation, Properties and Molecular‐Orbital Characterization of Some Fluoro‐Derivatives of Anthracene and Anthraquinone

Several fluoroanthracenes (I‐III) and fluoroanthraquinones (IV‐VII) were prepared, and their PMR and UV spectra, as well as dipole moments, recorded. These are discussed in terms of molecular‐orbital data, both of the pi‐electronic type (including nonbonding 2p‐orbitals) and of the all‐valence‐electron type. PMR signals can be assigned on the basis of such calculations. The interpretation of UV spectra is straightforward in the case of fluoroanthracenes, but other techniques are required for fluoroanthraquinones. Measured dipole moments are close to the theoretical, except in the case of 1, 4, 5, 8‐tetrafluoroanthraquinone. A distorted structure is proposed for this molecule.