Features of reactions of α-substituted acetylacetonate complexes

The reactions of coordinated ligands in acetylacetonate complexes of chromium and boron difluoride were studied by chromatograph mass spectrometry. It was found that bromo- and thiophenyl-substituted acetylacetonates of boron difluoride, unlike chromium complexes, do not interact with thiophenol. The interaction of thio-substituted chelates with SO2Cl2 also occurs differently. For chromium complexes, the reaction is accompanied by the replacement of the thioalkyl or thioaryl substituent by a chlorine atom. Thioethyl-substituted acetylacetonate of boron difluoride reacts with SO2Cl2 like aromatic analogues with chlorination of the ethyl group. Thioaryl-substituted acetylacetonate of boron difluoride does not react with SO2Cl2. In addition, it was found that bromo- and thiosubstituted chromium acetylacetonates react with sulfenyl chlorides with the replacement of the α-substituent by a chlorine atom. It was suggested that the difference in the reactivity of chromium acetylacetonates and boron difluoride is due to different charge distributions in the chelate cycle. The significant electroacceptor character of the BF2 group leads to the appearance of a positive charge on the substituent associated with the chelate cycle of the boron complexes.