Preparation and Crystal Structure of Tetraphenylphosphonium Triiodotetrabromide [PPh4][I3Br4]

Tetraphenylphosphonium triiodotetrabromide [PPh4][I3Br4] is obtained by the reaction of tetraphenylphosphonium bromide with iodine monobromide. It is the first example of an iodine rich, seven-membered polybromide. [PPh4][I3Br4] crystallizes triclinic in the space group P1̄ with a = 10.947(1) Å, b = 11.945(1) Å, c = 12.896(1) Å, α = 66.80(1)°, β = 77.21(1)°, γ = 85.73(1)°, and two formula units per unit cell. The final R indices [I > 4σ(I)] are R1 = 0.0362 and wR2 = 0.0944.