Study of Conversion of Polymeric Organophosphorus Ylide Complexes of Mercury(II) Halides to Phenazine Complexes: X-Ray Crystal Structures and Spectral Characterizations

The reaction of PPh3 with BrCH2C(O)PhNO2 leads to a new phosphonium salt [Ph3P-CH2C(O)PhNO2]Br (1). Reaction of the salt 1 with an appropriate base gave the free ligand, Ph3P=C(H)C(O)PhNO2 (2). The reactions of ligand 2 with mercury(II) halides form the C-coordinated polymeric complexes [(2)HgX2](n) {X = Cl (3), Br (4), I (5)}. Reactions of benzo[a]quinoxalino[2,3-c]phenazine ligand (L) with complexes 3, 4, and 5 cause the removal of ylidic ligand and lead to the formation of a new set of mononuclear mercury halides complexes {[(L)HgCl2] (6), [(L)HgBr2] (7), and [(L)HgI2] (8)} containing (L) as a bidentate ligand. The structures of 4 and 6 were confirmed by single-crystal X-ray analysis. The structure of the products were identified by IR, H-1, and P-31 NMR spectral data and elemental analysis.