Spectroscopic Studies of Photochemical Transformations of Cymantrenylquinazolinone Derivatives: Spectroscopic Studies of Photochemical Transformations of Cymantrenylquinazolinone Derivatives

For the first time, the photochemical properties of compounds 1-4 containing a cymantrene fragment at the 2- or 3-position of the quinazolinone have been studied. It was found that the -NC=O group in compounds 1 and 2 is capable of coordinating to the Mn atom with the formation of intramolecular chelates. The influence of the nature of the solvent and substituent in the side-chain of cymantrene on the thermodynamic and kinetic stability of the dicarbonyl complexes was studied. For the first time, the olefin chelate 9 was isolated; its structure was established by X-ray diffraction analysis and its photochemical and fluorescence properties were studied. The photolysis of compound 4 gave only stable intermolecular dicarbonyl complexes, in which the solvent can be easily replaced by n- and pi-donor ligands.