Spectroscopic Studies of Photochemical Transformations of Cymantrenylquinazolinone Derivatives

Abstract

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 π‐donor ligands.