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

摘要

By reaction of the hydrazones of mono- and 1,1'-diacetylferrocene with mono- and diketones a series of ferrocenylazines has been prepared. The crystal structures of the monobridged ferrocenophane [4](1)(1,4-dimethyl-2,3-diazabuta-1,3-dien) ferrocenophane (II) and of the dibridged ferrocenophane [4(2)](1,1')bis-(1,4-dimethyl-2,3-diazabuta-1,3-dien) ferrocenophane (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-planar bridges. In II and VII the bridges are in the E,E configuration. The electrochemical results show that the ferrocenium ions of the acetylferrocene and the azines are stable in solution whereas those of the hydrazones are unstable. In agreement with a slightly increasing electronic communication between the two ferrocene units, II undergoes two almost overlapping one-electron oxidations (Delta E degrees' = 0.09 V) whereas VII displays two more widely separated one-electron oxidations (Delta E degrees' = 0.12 V). [References: 22]