SYNTHETIC, STRUCTURAL AND ELECTROCHEMICAL STUDIES ON SOME FERROCENYLAZINES - CRYSTAL-STRUCTURES OF 1,4-DIMETHYL-2,3-DIAZABUTA-1,3-DIEN)FERROCENOPHANE AND 1,4-DIMETHYL-2,3-DIAZABUTA-1,3-DIEN)FERROCENOPHANE

By reaction of the hydrazones of mono- and 1,1'-diacetylferrocene with mono- and diketones a series of ferrocenylazines has been prepared. T he crystal structures of the monobridged ferrocenophane [4](1)(1,4-dim ethyl-2,3-diazabuta-1,3-dien) ferrocenophane (II) and of the dibridged ferrocenophane 2)](1,1')bis-(1,4-dimethyl-2,3-diazabuta-1,3-dien) fer rocenophane (VII) have been determined. II exists as a centrosymmetric molecule with eclipsed cyclopentadienyl rings and a planar MeC = NN = CMe bridge whereas VII has staggered cyclopentadienyl rings and non-p lanar bridges. In II and VII the bridges are in the E,E configuration. The electrochemical results show that the ferrocenium ions of the ace tylferrocene and the azines are stable in solution whereas those of th e hydrazones are unstable. In agreement with a slightly increasing ele ctronic communication between the two ferrocene units, II undergoes tw o almost overlapping one-electron oxidations (Delta E degrees' = 0.09 V) whereas VII displays two more widely separated one-electron oxidati ons (Delta E degrees' = 0.12 V).