Ethyltriphenylphosphonium perrhenate and (iodomethyl)triphenylphosphonium perrhenate

Ethyltriphenylphosphonium perrhenate, (C(20)H(20)P)[ReO(4)], and (iodomethyl)triphenylphosphonium perrhenate, (C(19)H(17)IP)[ReO(4)], have been crystallized from 2-propanol. Both crystal structures consist of phosphonium cations and perrhenate anions. The cations show the typical propeller-like geometry. In both crystals, the positions of the nearly tetrahedral anions are stabilized by weak C-H...O hydrogen bonds, and for the latter compound, I...pi interactions also occur.