CO3lhIUNICATIONS TO
1762
months in the absence of air. n'hen 111 was treated with an entire mole of iodine, the initially formed radical cation disappeared and an orangered solution remained. Concentration caused the solution to deposit orange-red crystals of the diiodide of V formed by transfer of a second electron to iodine. Purified by recrystallization from acetonitrile, the diiodide melted a t SS4-2S5°. Ph
l
Ph
Ph
Ph 1
Ph
l
I Ph
Ph
Ph I11
yh
Ph
Ph
V
I
IV
Ph
In a similar fashion, oxidation of I11 by silver nitrate in acetonitrile could be carried out in two discrete stages." The violet color due to IV faded upon addition of a second equivalent of silver ion, leaving a yellow solution of the dinitrate. Canary yellow prisms of the dinitrate were obtained from acetonitrile benzene (n1.p. 242-243'). The corresponding diperchlorate was prepared from the ethy1e:ie 111 with silver perchlorate as the oxidizing agent (canary yellow crystals from acetonitrile, n1.p. :3-kl-342°) - 1 nal. Calcd. for C:
