As—Halogen-Containing Compounds

Compounds of pentacoordinated arsenic(V) containing As—halogen bonds are summarized in Table VI. Compounds containing As—Br and As—I bonds are generally ionic and hence are not included in the table. For the same reason, compounds of type R4ASX have been excluded. 

Arsenic pentafluoride is made by the reaction between AsF3 or the oxide and elemental fluorine (166). The greater volatility of AsF5 compared with the trihalide is associated with the zero dipole moment of AsF5. Vibrational spectra of AsF5 have been interpreted in terms of Z)3h symmetry (12). 19F-NMR studies indicate that all five nuclei are equivalent even at the lowest temperature observable. This suggests 

Compounds of Pentacoordinated Arsenic(V) Containing Arsenic-Halogen Bonds 

If this reaction is run at low temperatures with less sulfur tetra-fluoride, RASOF2 is formed (174). 

All of the organyl tetrahaloarsoranes are readily hydrolyzed by water to the arsenic(V) acids. When heated in air, phenyltetrachloroar-sorane produces the dichloroarsane and chlorine, but when heated to 150°C in a sealed tube, it gives chlorobenzene and trichloroarsane. 

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