Reactivity of UI4(OEt2)(2) with phenols: probing the chemistry of the U-I bond

Solutions of UI4(OEt2)(2) in Et2O were found to deposit orange crystals of [H(OEt2)(2)][UI5(OEt2)] (1) upon standing at room temperature. The proton in the cation of 1 most likely originates from the surface of the glass vial in which the solution was stored. Reactions of UI4(OEt2)(2) with 1 equiv. of ArOH in toluene, followed by addition of THF, provides UI3(OAr)(THF)(x) (Ar = Ph, x = 3, 2; Ar = 2,6-Ph2C6H3, x = 2, 3). UI4(OEt2)(2) also reacts with 2 equiv. of ArOH (Ar = Ph, 4-(BuC6H4)-Bu-t, 2,6-Me2C6H3, C6F5) in toluene, followed by addition of THF, to generate UI2(OC6H5)(2)(THF)(3) (4), UI2(O-4-(BuC6H4)-Bu-t)(2)(THF)(3) (5), UI2(O-2,6-Me2C6H3)(2)(THF) 3 (6) and UI2(OC6F5)(2)(THF)(3) (7), in moderate yields. Complete conversion to the products requires the use of a dynamic vacuum to remove the HI generated upon addition of the phenol.