o-Semiquinonato and o-iminosemiquinonato rhodium complexes. EPR study of the reactions in coordination sphere of rhodium

► Dicarbonyl-o-semiquinonato rhodium complexes have similar structures in spite of different semiquinonato ligands. ► Mentioned compounds interact with tertiary phosphines forming square-planar phosphine-carbonyl species. ► Some of species attach additional molecule of PPh3 forming five-coordinate adducts which geometry is close to trigonal bipyramid.