Charge-transfer complexes of metal dithiolenes .22. Bis(maleonitriledithiolato)oxomolybdate(IV) - Bipyridinium ion pairs

The oxomolybdenum complex (NBu(4))(2)[MoO(mnt)(2)] (mnt(2-) = maleonitriledithiolate) 2 was characterized by X-ray structural analysis. By metathetic reaction with bipyridinium salts AX(2) ion pair charge-transfer complexes of composition {A(2+)[MoO(mnt)(2)](2-)} were isolated. Although a plot of the energy of the ion pair charge-transfer band vs. the driving force of electron transfer from the dianion to the dication afforded a straight line, the slope of 0.45 suggests significant deviations from the Hush-Marcus model. When bis(2-hydroxyethyl)viologen is the acceptor, in addition to the supramolecular charge-transfer interaction, hydrogen bridges are introduced between the two components as indicated by IR and X-ray diffraction analysis.