Synthetic, structural and electrochemical studieson some ferrocenylazines: crystal structuresof [4]( 1)( 1,4-dimethyl-2,3-diazabuta- 1,3-dien) ferrocenophaneand [42 ](1,1') bis( 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 beenprepared. The crystal structures of the monobridged ferrocenophane [4](1)(1,4-dimethyl-2,3-diazabuta-1,3-dien) ferrocenophane (II) andof the dibridged ferrocenophane [42 ](1, l')bis-(1,4-dimethyl-2,3-diazabuta-1,3-dien) ferrocenophane (VII) have been determined. II existsas a centrosymmetric molecule with eclipsed cyclopentadienyl rings and a planar MeC=NN=CMe bridge whereas VII has staggeredcyclopentadienyl rings and non-planar bridges. In II and VII the bridges are in the E,E configuration. The electrochemical results showthat the ferrocenium ions of the acetylferrocene and the azines are stable in solution whereas those of the hydrazones are unstable. Inagreement with a slightly increasing electronic communication between the two ferrocene units, II undergoes two almost overlappingone-electron oxidations (AE °' = 0.09 V) whereas VII displays two more widely separated one-electron oxidations (AE °' = 0.12 V).