The new stable low oxidation state arsenic(I) iodide reagent [(dppe)As][I] (dppe = 1,2-bis(diphenylphosphino)ethane) exhibits chemistry that is considerably different from its As-III analogues. While [(dppe)As][1] is not crystalline, the crystal structure of the derivative salt [(dppe)As][(dppe)AS(2)I(7)] is reported and is compared to that of [(dppe)AS](2)[SnCl6].2CH(2)Cl(2). The air oxidation of [(dppe)As][I] produces crystals of the salt [Ph2P(O)CH2CH2P(OH)Ph-2](2)[AS(6)I(8)].2CH(2)Cl(2) and suggests that, in contrast to previous studies, the reaction of the univalent arsenic iodide salt with certain oxidants results in the oxidation of the dppe ligand and the release of "As-I-I" fragments that oligomerize to form As-I clusters, Such reactivity is confirmed by the reaction of 6[(dppe)As][I] with 12Me(3)NO and 2[PPh4][I] to produce [PPh4](2)[As6I8] and 6dppeO(2). The reactivity is rationalized using density functional theory calculations.