Phosphoryl Dichlorobromide, POCl2Br, was made by passing a mixture of HBr and the vapour of POCl3 through a glass tube at 400° to 500° C., and also by the action of PBr5 on P2O3Cl4 (q.v.). A good yield is obtained from the halogenated alkyl derivatives. Phosphoryl ethyl dichloride when treated with bromine gives ethyl bromide and POCl2Br. Phosphoryl ethoxydichloride, which may be obtained from alcohol and P2O3Cl4, is acted upon by PBr5 according to the equation
PO(OC2H5)Cl2 + PBr5 = POCl2Br + POBr3 + C2H5Br
The formula was established by analysis and by the determination of vapour density. The density is 2.12065 at 0° C. and 1.83844 at the boiling-point, 137.6° C. The coefficient of expansion is expressed by the equation
vt = v0(1 + 0.00100518t + 0.0649053t2 + 0.0844065t3)
The solid melts at 11° to 13° C.
The chemical properties are similar to those of POCl3. When heated the compound dissociates into POCl3 and POBr3. |