Crystal structure of selenium-substituted acetylacetonates of boron difluoride

Abstract

The molecular and crystal structure of boron difluoride acetylacetonates containing selenophenyl (1), diselenide (2) and selenocyanate groups (3) at the central carbon atom (γ) has been determined. As a result of comparing the structure of selenium- and sulfur-substituted complexes, it is shown that the replacement of a sulfur atom with a selenium atom practically does not change the relative position of substituents and chelate cycles, as well as the values of the main angles. The packing of complexes 2 and 3 in crystals repeats the packing of sulfur-containing analogues. For phenyl-substituted selenide and sulfide, the crystals are not isostructural. In the diselenide complex 2 molecules crystallize in pairs with one chelate cycle of each molecule participating in pair formation. The pairs are linked by an interaction similar to the stacking interaction. The second chelate cycle of each molecule in the pair does not participate in intermolecular interactions. In the acetylacetonate complexes studied, the chelate rings are not planar. These cycles have a “boat” conformation. The magnitude of bending of the cycle is determined by intermolecular interactions.