Hydrazine → 1,4-Benzenediamine, N,N'-bis(4-aminophenyl)-

Participants

Reaction Steps

About 5.0 g of the tetraaniline in the emeraldine oxidation state synthesized in Example 2 was dissolved in 250 ml ethanol. 10 ml of anhydrous hydrazine was added with constant magnetic stirring. The reaction system was stirred for about 2 hours. The blue precipitate was collected by vacuum filtration and washed with 100 ml cold ethanol in 3 portions. The precipitate was suspended in 700 ml ethanol containing 1 ml of phenylhydrazine which was heated to reflux for 0.5 hours. The heat was removed and about 2.5 g of active carbon was added. The suspension was heated to reflux for another 0.5 hours and then was filtered hot by vacuum filtration and the filtrate was cooled in an ice bath. The off white precipitate was collected by vacuum filtration and washed with 50 ml cold ethanol and dried under dynamic vacuum. This precipitate was readily oxidized to, or approaching, the emeraldine oxidation state by air, especially if wet or in solution. Hence, minimum exposure to air is necessary in order to obtain the tetramer in the leucoemeraldine oxidation state. The dried precipitate was ground and stored in a dark bottle under Argon in a refrigerator. The yield was 3.5 g or 70%. A typical analysis for the tetraaniline in the leucoemeraldine oxidation state C24H22N4 was C: 78.38; H: 6.02; N: 15.28, total 99.68%. Calculated, C: 78.68; H: 6.05; N: 15.29. Mass spectrum (CI): 367 (MH+ /e). 1H NMR (DMSO): 7.66 (s,1), 7.42 (s,1), 7.15 (s,1), 7.12 (t,2), 6.88 (m,12), 6.65 (t,1), 6.52 (d,2) and 4.63 (s,2). 13C NMR (DMSO): 145.7, 142.6, 139.9, 139.8. 135.1, 134.1, 133.5, 129.0, 121.0, 120.5, 119.6, 117.7, 116.3, 115.9, 114.9 and 114.4 (TMS std.). These data are in agreement with the proposed structure, and are presented in FIG. 3 where it is identified as "B."

Provenance & Evidence