Unusual condensation of N-phenylsemiquinonediimine ligands coordinated to the Ni-II atom with an acetone molecule to form a heterocycle

The reaction of a mononuclear Ni-II semiquinonediimine complex, viz., Ni[1, 2-(NPh)(NH)C6H4](2), with silver triflate was investigated. The starting mo nomer was not oxidized in benzene or CH2Cl2 solutions, instead, a solvate o f the complex with C6H6 was formed. According to the X-ray diffraction data , the solvate is characterized by an unusual molecular packing with short C -H(C6H6). . . Ni and C-H(C6H6). . .N-H contacts. An analogous effect is obs erved in the crystals of the solvate Pt[1,2-(NPh)(NH)C6H4](2).C6H6 Grinding of the nickel complex with silver triflate (the reagent ratio was 1 : 5) i n the presence of acetone led to the oxidation of the complex, yielding tet rahydroimidazophenazinium triflate, whose structure was established by X-ra y diffraction analysis.